Electricity Saving Tips For Homes And Offices

Choose the right sized water heater/geyser for electricity saving

By on April 22, 2016

Planning to buy a new water heater/geyser and confused with the options available and sizes available? If yes then you are not alone, there are many people who face the same situation while buying a water heater. While buying a water heater one has to make sure that it not just suffices the need of the family but also does not increase electricity bills (or units consumed) significantly. People might look at the wattage of the water heater to determine the amount of electricity the water heater might use, but wattage does not have any impact on the electricity consumption of water heater. We will try to list some facts that can help you decide on the size and type of water heater.

What factors does electricity consumption of water heater/geyser depend on?

Electricity consumption of water heater depends on:

  • Volume of Hot Water used: This is the main driving factor of electricity consumption by water heaters. The more the hot water you use, the more the electricity it will consume.
  • Tap (Input) water temperature: Places with colder climates need lot more heating than places with warmer climates. A water heater in Kashmir will require lot more electricity than a water heater in Tamil Nadu.
  • Temperature of water used for bathing: Please note that this is different from thermostat temperature.
  • Thermostat temperature: This is by default set to about 60oC for most water heaters. Some heaters have external control to change this setting.
  • Standing Losses: Yes, water heaters do lose heat and this is calculated as standing loss. It is the heat lost through the surface of the water heater. BEE defines standing losses as the energy consumption of a filled water heater, after steady state conditions have been reached when connected to electrical supply, when no water is drawn. Much of this depends on the quality of material used for making the water heater. Branded water heaters are of better quality and thus they are preferred. BEE also rates only the branded water heaters.

How much water is required for my family?

A very straightforward guideline for the same is as mentioned below:

  • For bathing using bucket water: 15 lts/person per bath (one bucket). If more buckets of water are used, then add 15 lts/bucket.
  • For bathing using shower: 25 lts/person per bath.
  • For tub bath or extended shower bath: 35 lts/person per bath.
  • For washing cloths: 10 lts/person per day.
  • For washing utensils: 5 lts/person per meal.

(Source: http://www.teriin.org/ResUpdate/reep/ch_9.pdf)

So if there are 4 people in the household and all 4 take shower bath. Then the total hot water requirement per day of the household is 100 lts. Keep adding the water per use as per the guidelines above and you will get the water requirement of your house.

What is the ideal temperature for bathing?

Although most water heaters have a thermostat setting of 60oC, which means that, the water is heated up to 60oC but can human body handle water at 60oC? The answer is NO. Water at 60oC is too dangerous for human body and can cause first-degree burns. Human body temperature is 37oC and any temperature above it feels hot. A temperature of 46oC is quite hot but far less dangerous than water at 60oC. So even though your water heater heats the water to 60oC, you need to add extra cold water to make it bearable.

(Source: http://www.telegraph.co.uk/health/3318578/So-Mr-Prescott-how-hot-should-my-bath-be.html)

So what is the ideal Electricity Units that are required by your family?

Heating of water is a classic thermodynamics problem and has a straight forward formula:

Heat required = M (Mass of water) x Cp (Specific heat of water) x delta T (Difference in starting temperature and desired temperature).

A simplified solution to calculate electricity units is:

                                    Ideal Units for heating = Volume of Water x Temperature Difference x 0.0012

So if your family’s water requirement is 100 lts of hot water per day and you prefer to use water at 40oC and your tap water temperature is 20oC. Then the ideal units for your water heating requirement is:

                                    100 x (40-20) x 0.0012 = 2.4 units per day.

Will all water heaters consume ideal units of electricity?

No. The amount we calculated above is the ideal units and not the actual units. The actual units depend on the size of water heater, standing losses and the way you use it. The bigger the size of a water heater higher are the standing losses, because more is the surface area. Typical 100 lts water heaters have standing losses of more than 1 unit/day, 70 lts water heater is close to 0.9 units/day, and it decreases as the size decreases.

If you leave the water heater on throughout the day then you certainly loose the full standing loss units in a day. The way to minimize it is by heating the appropriate amount of water that is required which can be done by switching the water heater on before use and switch it off after use. This way the standing losses will be minimized to the period when water heater is used. Also do not waste any extra hot water because that is waste of electricity.

So does it mean that you should buy smallest volume water heater?

Depends. If the water heater is too small then the amount of hot water (even if it is at 60oC) will not suffice the need of single person (even after adding cold water). You will have to wait for longer for the water heater to heat the desired amount of water or keep the output flow of water from the heater low.

So what is the ideal size?

Ideal size of water heater should be close to the volume of hot water required at one go. If people take bath one by one and use 25 lts of water, then a 25 lts or a 15 lts of water heater will make sure that the water is optimum hot when one goes to take bath (at places where tap water temperature is not too low). If the tap water temperature is too low (especially in cold places) only a 25 lts capacity hot water will work if 25 lts of water is required for a bath. If water heater is connected to 2 bathrooms then ideal size is 25 + 25 = 50 lts, because 50 lts of water can be used simultaneously. This does not mean that 6 lts water heater will not suffice; it’s just that it will take more time to heat the same amount of water or you might have to bear with cold water at the end of your bath. Ideal sizes are those that generate enough heat that are good for maximum instantaneous use.

How does the wattage of water heater effect?

Wattage of water heater makes the water heat faster or slower. If you buy an instant water heater of 4.5 kW the water will heat faster than a water heater of 2 kW. At times a 4.5 kW instant water heater can also heat the water required for bathing and can save electricity (by stopping wastage of extra hot water). The only downside of 4.5 kW water heater is that it increases the electricity load of your house which means that you connected load will have to be increased which may increase the fixed charge component of your electricity bill.Infographic11

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I have a multi shower system from Grohe and Artize. We are to install a water heater at our place and I had a boiler previously installed but its body failed. When asked the plumbing consultant, he said that a three phase line is essential for an inline geyser. I would like to know if it is actually required (the three phase line) or a single phase electric line can help in this situation.

These showers put out almost 20L/min at 6ps.

Abhishek Jain (Mod)

Hi Ishan,

Firstly, three phase is not required for a geyser. Geyser runs only on single phase. But I guess your consultant recommended three phase because if you go for an instant geyser, it will be 4.5 kW geyser and it will increase the total load in your house and usually if the total load in the house is more than 7 kW, then electricity distribution companies will suggest you to go for 3 phase.

To give you a analogy to understand it easily .... imagine you have a truck to run. You can easily run it on a single lane road. But then your truck will not be the only thing running on the road and there will be many other cars, etc (which all can also ideally run on single lane), but just so that there is no traffic jams, the truck will be advised to run on a 3 lane road.

An instant geyser is like a truck (a high electricity consuming appliance), and to keep other things running along with it (without a traffic jam), you need a bigger connection (a three phase connection).

Now having said that, I do not think any electric instant geyser can give you hot water at 20L/min. You will have to go for a storage geyser (I am not sure what you meant with inline geyser). For that flow rate you will need a 50 lts geyser. However, most 50 lts geyser available in market are max 2 kW or 3 kW. And they will take up good enough time to heat the water (atleast 30-45 mins). And you will have to keep the heater on much before the water will be used. If you go for 2 kW one then I do not think it will be very necessary for a 3 phase connection.


Hi Abhishek,
Thanks for giving detailed information. We are having single connection point for a geyser that will be used for 2 bathrooms. There are only 3 family members in the house who will be using bucket bath. I am planning to get a Racold 6 ltr Instant geyser. Do you think that will be sufficient or should I be going for a storage water heater of larger capacity?

Thanks in advance!!

Abhishek Jain (Mod)

Depends on how cold it gets in your city. I have a 6 lts geyser in one of my bathrooms and it works perfect for a bucket bath (a bit less for shower bath), and I am in Mumbai where temperatures are not too cold in winters/monsoons. If it gets too cold, then 10 lts water heater would be good.


Hello, thanks for all the information. I am trying to estimate power consumption of the following electric heater which is fitted in a 300 liters tank: The heater is kept switched on for around 8 hours. The wattage of the heater is 3kW. I do not know the water consumption details.

Is it possible to estimate the power consumption per day using only this data?
I am a bit worried due to the thermostat.

Abhishek Jain (Mod)

Hi Apoorva,

All water heaters are equipped with a thermostat. This is because if they do not have a thermostat then the water will keep on heating and will get converted to steam and that will burst the tank. So it will surely have a thermostat.

And as mentioned above the electricity consumption can be calculated using this formula:

Ideal Units for heating = Volume of Water x Temperature Difference x 0.0012

Now suppose you heated the water from 20 to 40, then the electricity consumption would be 300 x (40-20) x 0.0012 = 7.2 units.

There would be extra electricity consumption that would be because the standing loss of the tank. And that depends on the insulation of the tank. If insulation is bad, then heat loss will be fast and the thermostat will sense that the water has lost temperature and it will start the heater again. Once it again senses that the water has reached the set temperature, then again it will switch off the heater.

The heater wattage just determines how fast the water will get heated. It has no impact on actual electricity consumption. That depends on the water volume being heated.


I got a 3litre geyser, what is it helpful with? Can i use it for bathing purpose? We are a family of 3 and have shower.

Abhishek Jain (Mod)

Instant water heaters are not good for showers. It will soon run out of hot water. May work ok for bucket bath depending on your city. If the city is too cold in winters, then it would not work. For places like Mumbai or Chennai, it may work. You can read more here: https://www.bijlibachao.com/water-heaters/should-you-buy-instant-water-heater-for-your-bathroom.html


Hi Abhishek

i stay at 7 floor of a 14 floor building is it advisable to buy geezers with pressure valves

Abhishek Jain (Mod)


Pressure Valves are for safety of the geysers. In case the pressure inside the geyser increases, it will open up and release the pressure. If you think that the water pressure is really high then you can go for it. Most brands these days mention the water pressure that the models can handle. You may go for a model that can handle high pressure in case you feel that the water pressure is high in your building. In general for high risers, it is better to go for such models that can handle high pressure.


Hi Abhishek
Suppose i need 100 liters for a long shower at temperature of 40 degrees celcius, then what could be the best scenario assuming no standing loss/cost of investment

1) I install a 100 liter geyser and set 40C
2) I install a 50 ltr and set at 50C approx and mix little cold water
3) Just install a small geyser and set at highest setting and mix with cold water till i get 40C?

Also, does it take more energy to heat water from 40 to 60 than say, 20 to 40? I think 0 to 20 may be really bad.

Abhishek Jain (Mod)

Hi Veepul,

Energy taken to heat water from 0 to 20 will be slightly more than what it would take it to get it from 20 to 40, but it will not be a huge difference. It will be quite close as property of water just changes slightly with varying temperature. So for all practical purposes it could be assumed the same for the same temperature difference.

Now a larger geyser will have more standing losses and thus the best strategy is to minimize the size of the geyser. A geyser can heat water till 60-70 degrees and the best strategy is to get a geyser that can heat water to 60-70 and then you mix cold water with it to get water at 40 degrees.

Now suppose you need 100 lts water and temperature of incoming water is about 20 degrees. Then as per the formula above you need 2.4 units of electricity.

The same electricity can be used to heat water to 60 degrees, and the volume of that would be: (2.4/((60-20)*0.0012)) = 50 lts.

So if you need 100 lts water in one go then a 50 lts water heater would be sufficient. Assuming all the inputs mentioned above are right.

You can get a smaller geyser as well, but then shower will be difficult to use and you will have to rely on bucket. Because with a smaller water heater, you will have to reduce the flow rate from the tap so that heater gets enough time to heat the water to desired temperature.


I am only receiving 100V supply. Does my 2 KW geyser consume the same 2 units/ hour of electricity?


no 1 unit/hr. Less volt means less flow of current, current directly proportional to volt

Abhishek Jain (Mod)

A 2 kW geyser will always consume 2 units of electricity per hour irrespective of the voltage. If voltage is low, it will draw more current.


current = volt / Resistance. Here Resistance is fixed. Volrtage directly proportional to current. So less volt means less current flow.


this reply is wrong. he is not having basic knowledge of electricity


Sir if I will use a tranformer to step up the voltage will their be any effect on the electricity units consumed / hour or will it remain same 2 units/hour


increase voltage means increase in current, so quick heating and more heating. Watt = current2 x resistance. hence consumed watt will be more than 2 units/hour

Abhishek Jain (Mod)

There will be losses in transformer of about 2-3%.


And also please suggest me that should I use the transformer as the water will become hot quickly?

Abhishek Jain (Mod)

Why are you using transformer to heat water? You can heat water directly with an induction rod. Why do you need to transfer energy from one circuit to another to heat water?


Is induction rod a better option than electric geyser for low voltage(100V)?Will it save electricity?
And please guide me which induction rod to buy?

Abhishek Jain (Mod)

My bad. I did not go through the previous comments properly before replying to you. No Induction rod is not better than a geyser. For better efficiency you should go for a geyser only. Do check for the operating voltage of the geyser given on the model. If the operating voltage is about 200-240 then you do need a voltage stabilizer (or transformer as you say). If the operating voltage is less (and about 100V) then you cannot use the water heater at 100V. And yes, you will get better performance (faster heating) only when you use the geyser at right operating voltage as mentioned on the model.


Can you tell me which voltage stabilizer will be good?

Abhishek Jain (Mod)

For 2 kW system you need a stabilizer that would be rated about 3 kVA. If you are in India then VGuard is a good brand.


Does that mean for 2KW transformer losses will be about 40-60Watt/hour?

Abhishek Jain (Mod)

Yes a 2 kW transformer would have about 40 W losses. In an hour 40 Watt would mean 40 Wh or 0.04 kWh or 0.04 units of electricity.


Hi Abhishek,
we are a family of four and need a electric water geyser for kitchen, in north India.
could we go for instant or 6Ltr geyser or any other you suggest.

Abhishek Jain (Mod)

Hi Navdeep,

In North India 6 lts geyser would be a safer option. Instant ones will not be good enough for slightly longer water usage (considering the fact that it gets too cold in winters). Had it been just hand wash, instant would have worked. But for kitchen usage where you may need it to wash utensils, I think 6 lts would be better.


I appreciate your efforts.


hi abhishek ,
i have family of 6 members and i need a electeric water geyser so could you pls suggest what type with tank or tankless and how much litres of water geyser i have to buy..... i dont have any knowledge about water geysers...

Abhishek Jain (Mod)

Hi Jai,

I would not suggest a tankless (or instant) water heater if you plan to use it for bathing purpose. Also a lot depends on the method used for bathing. In most cities in India a 10 lts water heater is good enough for bucket bath and 15 lts is good for shower bath. If the climate is hot (like in mumbai or chennai) even a 6 lts is good enough for bucket bath. Also if you prefer longish showers (which actually is not good for the environment :) ) then you can go for a 25 lts water heater. But then 10 and 15 lts are the safest choices.

As far as tank or heating element is concerned, I would suggest you to look for a brand that can give you longest warranty on each of these elements. For water heaters brands do mention warranty for tank as well as heating element as both of these can get damaged due to corrosion. They need to put good corrosion protection for these two.

If you want to know about different types of tanks and corrosion protection then you can read this post on our website: https://www.bijlibachao.com/water-heaters/coating-storage-water-heater-thermoplastic-stainless-steel-enamel-coating-glasslined.html

Most top brands: Havells, Bajaj, AO Smith, Racold, Morphy Richards, Venus, Ferolli, etc have good corrosion protection for tank and heating elements.


hi Abhishek,
You are doing a good job. Keep it up.
I want to buy a water heater for my new house with plumbing facilities for solar water heater also. We have never used water heater. And so Im new to this.
We use 3 different bathrooms simultaneously. We need 3 water heaters or one heater that may supply to 3bathrooms.
We use hand shower rather than head shower. Sometimes bucket bath.
Kindly suggest a water heater

Abhishek Jain (Mod)

So here is the thing and this is what I suggest to most people: size of water heater does not depend on number of people or number of bathrooms. It depends on the maximum volume of water to be used in one use. From one use I mean in a bathroom it would be one person taking a bath. If the water heater is to be used for bucket bath then 10 lts water heater is sufficient in most (99%) cases in India. In places where the climate is not too cold (like mumbai or chennai) even a 6 lts one would be good enough for bucket bath. For shower bath 15 lts water heater is sufficient. Because after mixing with cold water, you get sufficient water for one person to take a bath. And by the time next person goes in, it becomes hot again (assuming the time difference between two use is about 15-20 mins ... which is mostly the case).

In most cases bigger ones are no good if you want to save electricity. Sometimes people think that they can have one single water heater for multiple bathrooms, but from an energy saving point of view, smaller water heaters for individual bathrooms is better.

Now if you plan to go for solar water heater then that would be the best thing to do. You can have a hybrid system installed where the water is originally heated in a solar water heater and then it goes to individual bathrooms where there are individual heaters which can heat the water just in case the water is not hot enough. That can save you a lot of electricity. You can go for a 100 lts solar water heater that is connected to all the rooms where you need hot water.

You can have a look at the top most efficient water heaters on this page on our website: https://www.bijlibachao.com/top-ten-appliances/best-water-heaters-geysers-brand-in-india-by-standing-loss-and-size.html

Brands like Havells, Bajaj, AO Smith, Racold, Venus, Morphy Richards, Ferolli are good.


Thanks for your immediate reply. Your suggestion was useful.
The link you specified has only electric heaters.

Abhishek Jain (Mod)

We do not have data on Solar Water Heaters right now. When we have it, we will publish the same.


Hi, I just bot a new vguard 6 ltrs storage geyser for a family of 3 for bathing using bucket however after initial cut off (after 25 mins) it only gives less than half bucket hot water. Even if i mix it with cold water to fill the bucket, the water becomes cold. I have to wait for next cut off for about 10 mins for more hot water. It is not hitting instantly. What are my options to achieve best of it

Abhishek Jain (Mod)

6 lts would typically be less than half bucket. Which city are you in? In cities with extreme cold climate, a 10 lts water heater is a safer option for bucket bath.

Do you have a knob on water heater to change the heating level? If yes then try to keep it at the hottest level. If not then it will be difficult to use this water heater.


Thank you Abhishek. The model is sprinhot and im not sure if there is a knob for setting the temperature. Is there a way to atleast get continuous hot water after initial cut off? Or any setting which can be done on the mixer tap?

Abhishek Jain (Mod)

You can slow down the flow rate of water from the tap. Slow flow rate may most likely get you continuous hot water. But as I said, 6 lts may turn out small especially if you are in a city where the climate is very cold (like Delhi or most parts of north India). 10 lts model is better in case you are in North.


In my city ground water is hard then which geyser should I buy...... Water hardness will effect geyser????..... Plz write some model no for hard geyser......

Abhishek Jain (Mod)

It will be important to decide the right size before buying. A 10 lts would be good for bucket bath and 15 lts for shower bath. You can check the list of top efficient models on this link: https://www.bijlibachao.com/top-ten-appliances/best-water-heaters-geysers-brand-in-india-by-standing-loss-and-size.html

Havells, AO Smith, Racold, Bajaj, Morphy Richards, Ferolli, Venus are some good brands.


I am considering a water heater tank size for shower of: 3 litres, 15 litres or 25 litres for a flat in Tamil Nadu. Heaters under consideration are 2kWh units. If water has to be heated from 25 deg. C to 60 deg., how long time in advance would one have to turn each unit on in advance?

Abhishek Jain (Mod)

If you use the formula given above you need

0.126 units of electricity to heat 3 lts water
0.63 units of electricity to heat 15 lts water
1.05 units of electricity to heat 25 lts water

A 2 kW heater gives 2 units of electricity in 1 hour. So to heat the water it will take

(0.126/2)x60 = 3.78 minutes to heat 3 lts
(0.63/2)x60 = 18.9 minutes to heat 15 lts
(1.05/2)x60 = 31.5 minutes to heat 25 lts

Now suppose you need 15 lts hot water at temperature of 40 then you cannot get it in 3.78 minutes using 3 lts water heater. If you mix 12 lts of cold water to 3 lts hot water, the temperature will be lower than 40. You will have to keep it on for some more time to get 15 lts.


Thanks for the answer. Now, Let us assume that I spend 10 minutes for a shower, that I spend 20 litres and that I am a waterhog, leaving the water running all the time. Let us also assume that 40 C is a good water heater exit temperature, allowing for some cooling on the way from the tank to the (dirty) skin.
Then the water must be running at 2 litres/minute. Warming up from 25 C to 40 C as per the formula = 0.36 units/minute or 0,36*60 kWh= 2,16 kWh. So, a 2kW unit can (almost) keep up, warming the water as it flows through.
The 3 liter tank will be ready with 40 C water after (40-25)/(60-25)* 3,78 minutes = 1.62 minutes, the 15 liter will be ready after 8.1 minutes and the 25 liter ready after 13.5 minutes.
So, if I got it right, it is silly to go for larger size than 3 liters. Unless my assumptions in the first paragraph are unrealistic. Would you comment on this?
Thanks, PeP

Abhishek Jain (Mod)

Assuming that you need 2 lts per min of water. You need:

2 x (40-25) x 0.0012 = 0.036 units/min

A 2 kW heating element will give 2 x (1/60) = 0.033 units/min.

which will make the water heater mostly work in your case. However, 2 lts per min is very slow flow rate. A typical tap has flow rate of about 6-8 lts/min or more. Also water temperature of 25 degrees will not be there in every city (it will mostly be in warmer places).

We have done some analysis on this and published it on this page: https://www.bijlibachao.com/water-heaters/should-you-buy-instant-water-heater-for-your-bathroom.html

It is always better to go for the smallest possible water heater. If you get water at 25 degrees then even a 6 lts water heater would work ok (I have one in my house in Mumbai and it works fine). Though even with 6 lts water heater it is difficult to have longish showers (5-10 mins is fine). 10 lts is good enough even for longish showers (although from an environment perspective it is great that people do not have longish showers :) ).


Thank you gain for excellent, theoretically grounded, but practical advice that I have enjoyed as so many others, not only regarding the present issue (water heater dimensioning), but earlier also on A.C.s, fridges, inverters, stabilisers and other appliances. In cyberspace, where there is really no quality control of the advice being offered, your site and your advice stick our above most other web sites.
Wishing you success, - /PeP, Chennai

Abhishek Jain (Mod)

Thanks for the good words. I am glad that you found the information useful.


what is the actual power consumption of Havells 3L 3KW Neo EC Instant Geysers

Abhishek Jain (Mod)

If you ask about instantaneous power consumption then it is 3 kW. But actual power consumption will depend on the volume of water heater and also a bit on the time for which it is kept on.

Wattage is like Speed. So 3 kW is the rate of electricity consumption.

Units consumed (or kWh) is like distance. Depends on how long and how fast you use something.


Hi, We are only two adult members in family and lives in Delhi. I want to install storage water heater with TEMPERATURE CONTROL facility for bathing by bucket. Can you please suggest capacity of water heater ?


Hi, We are only two adult members in family and lives in Delhi. I want to install storage water heater for bathing by bucket. Can you please suggest capacity of water heater ?

Abhishek Jain (Mod)

10 lts water heater should be good enough for your needs.


I want to buy a water heater for home. We are 4 people(3 adults and 1 kid).I selected Reconnect RHWHE1502 Instant Water Heater, 15 litres.. Is it good? Can you recommend ?

Abhishek Jain (Mod)

As you have asked about a specific brand, then I will just copy and paste a reply that I have given to someone else in the past:

Since there is a huge demand for cheap products in India, there are many companies that are importing cheaply manufactured products from China and putting their own brand name on them and selling it in Indian market. They are not the OEM (or Original Equipment Manufacturers). Most electronic retail stores have such brands like Future Group has Koryo, Reliance has Reconnect, Vijay Sales has Vise, Croma has Croma. These guys are not OEMs but they are just importing from china and putting their name (brand). If you want to buy them, you can buy them at your own risk.


Then which one should I go for ?

Abhishek Jain (Mod)

Havells, Bajaj, AO Smith, Racold, Morphy Richards, Ferolli are some good brand .... You can check the list of top most efficient water heaters on this link: https://www.bijlibachao.com/top-ten-appliances/best-water-heaters-geysers-brand-in-india-by-standing-loss-and-size.html


Hi i'm looking for Gas geyser with Auto off and Auto overheating protection - we are the family of 4 + 1 kid.
kindly suggest the best Gas geyser to buy.

Abhishek Jain (Mod)

Almost all top brands have gas water heaters these days. You can check Bajaj, Havells, AO Smith or Racold gas water heaters.


Hi we are looking for geyser for 2 people. We stay in Hyderabad and it's v.cold now.What capacity is better for shower? Which brand ?

Abhishek Jain (Mod)

Hi Pallavi,

A 15 lts water heater should be good for your needs. You can look at the list of top most efficient water heaters on this link: https://www.bijlibachao.com/top-ten-appliances/best-water-heaters-geysers-brand-in-india-by-standing-loss-and-size.html

As far as brand is concerned, AO Smith, Havells, Bajaj, Racold, Venus, Ferolli, Morphy Richards are good brands.


Thank u for ur quick response. What about v guard?

Abhishek Jain (Mod)

Hi Pallavi,

VGuard is also a good brand. The most important thing with water heaters is that you should switch it on before use and switch it off immediately after the use to make sure it does not waste electricity. As long as you get a decent brand and use it right it would work out good.

Additionally if you want to control electricity consumption then buy a water heater with external thermostat using which you can reduce the heat level of the water. Lower the temperature setting, lesser will be your electricity consumption.


I have installed a 1ltr 3000w insta geyser of USHA in my flat. However it shuts down itself and the whole power supply after being switched on for 5-10 seconds. Since then I have not been able to use it
My friend in the same society (same building) has a 1ltr 3000w bajaj insta geyser and he has been using it without any issue. We both have the same 3Kv power supply. I tried switching off all the appliances including the refrigerator but in vain. Any solution Abhishek?

Thanks in advance!

Abhishek Jain (Mod)

Ask your electrician to check the capacity of the circuit breakers in your house. The wiring/Circuit Breakers in your house are not able to handle the load of the instant geyser. Your electrician should be able to help you.


Hi, i was looking for instant water heaters for my bathroon in pune for bathing purposes, we are a family of 5, but was confused with 1ltr, 3ltr and 6ltr variety. how does the capactiy affects the energy consumption.

Abhishek Jain (Mod)

By the way as mentioned on this article above, electricity consumption does not depend on the size of water heater. It depends on the volume of hot water you use.

Abhishek Jain (Mod)

Instant Water Heaters are not good for bathing purpose. I would suggest that you read this: https://www.bijlibachao.com/water-heaters/should-you-buy-instant-water-heater-for-your-bathroom.html


I want to go for 6L 500W geysers to make good with not using gas geyser. No doubt I have to wait for water heating. We are 4 persons. We are living in a moderate temp and 6L per person is sufficient. How much power consumption will be there? Pl let me know

Abhishek Jain (Mod)

If we assume that the temperature of water on the tap is about 25 degrees and you heat it to 65 using the water heater (assuming that you will mix it with cold water while using it .... and 65 degrees is the temperature to which your water heater heats the water), then the amount of electricity consumed would be:

6 x (65-25) x 0.0012 (formula give above on this page) = 0.288 units of electricity per person.

For 4 people it would be 4 x 0.288 = 1.152 units.

There will be some losses as well but that will not be more than 0.1 unit per day. So you would consume roughly 1.25 units per day.


Hello Abhishek,
I am from Vadodara (Guj). We are family of 4 members. I have selected two model (6 liter, for bucket bath) of Electric Water Heater. one is Haier Quadra ES 6V Q1 6-Litre & AO Smith HSE-SBS- 006 6-Litre 3000-Watt. Haier model comes with incoloy heating element, PUF insulation. on other hand in AO Smith model comes with Glass coated heating element & Blue diamond glass lined tank. Please suggest me, which model will be right choice for me as I am confused on Heating element & tank coating/Insulation.

Abhishek Jain (Mod)

Both have good corrosion protection and insulation. Both are giving similar warranties. AO Smith model is more energy efficient and AO Smith is a better brand for water heaters. So I think you should go with AO Smith model.


Thanks for your advice and quick response. your suggestion means a lot.


Hello Abhishek,

I am looking geyser for 1 person/ 1 bathroom only and it is for showers only .Can you pls guide me .. My budget is below 5k.
I will blindly buy whatever you suggest as I saw your blog is very informative.


Abhishek Jain (Mod)

Hi Harsh,

Which city are you in? Because in place like Mumbai a 6 lts water heater may suffice, but in Delhi it may fall short.


Noida .. If you can share the link i will buy .. really appreciated .. thanks

Abhishek Jain (Mod)

In Noida a 10 lts model would be better. I could not find a reputed brand in your price range. The only one that I could find on Amazon with good rating was this one: http://amzn.to/2eZ1DcG .... But I am not sure about the brand.


I am moving to a new home. My flat has 2 bathrooms, one is common and other is attached to the master bedroom. We are 2 members, but sometimes parents/siblings visit our place. The attached bathroom has solar supply. I like to have warm showers. Plz suggest appropriate Geyser/s
I am planning to buy a 3 ltr. geyser. Will that be sufficient?
Is 10/15 ltrs geysers (price almost the same) really required?
I want geyser which will fulfill my need - price & electricity efficient, Durable, Reputed, ideal for showers.

Abhishek Jain (Mod)

When you say Solar Supply, you mean hot water supply from solar water heater and you want a new geyser to heat water if hot water from solar is not sufficiently hot? If that is the case then 3-6 lts water heater should be good enough as it will just supplement solar water heater.

For other bathroom 3 lts may not be sufficient. See here is the challenge, a 3 lts water heater can just store 3 lts water. It may have a 3-4kW heating element to heat water, but once your 3 lts are over (obviously mixed with cold water), then the next volume of water that flows in does not get sufficient time to heat up well. So you will not get a continuous flow of hot water. A lot also depends on temperature of water incoming to the geyser. If it is not too cold, then it will heat up fast, but if it is cold, then you won't find it comfortable to take a bath. So if it acts as a supplement to solar water heater, then it may work depending on the temperature of water coming from solar water heater. But for standalone, it may not be sufficient for bathing. Typically, if you use bucket you use about 10-15 lts of water (size of a typical bucket) or if you take shower then you use 15-25 lts. So depending on the climate of your city a 6-10 lts water heater will be sufficient for bucket bath and 10-15 lts is sufficient for shower. Please note, if the climate is too cold then be on the higher side.


We are 2 members and we live in hyderabad. We already have solar water heater for complete apartment so i am mainly looking for water heater in winter and rainy seasons. We use bucket bath mostly. I am thinking about 6L instant or 10/15L storage in Racold. What you will suggest wrt durability and life and energy effecient. Which one will be good choice instant or small storage.

Abhishek Jain (Mod)


6L water heaters are not classified as instant. They are classified as storage. Only 1 and 3 lts models are classified as instant. You can get list of top models of storage water heaters on this link: https://www.bijlibachao.com/top-ten-appliances/best-water-heaters-geysers-brand-in-india-by-standing-loss-and-size.html

For bucket bath 6 or 10 lts models would be more than enough.


We are 3 members in Jamshedpur. Use of water for bathing and morning time brushing.. What will be your recommend size and brand of geyser which is value for money? Please help me.

Abhishek Jain (Mod)

Depends on what you use for bathing: bucket or shower. For bucket bath, 10 lts water heater is good enough and for shower 15 lts is better. You can look at top models on this link: http://www.bijlibachao.com/top-ten-appliances/best-water-heaters-geysers-brand-in-india-by-standing-loss-and-size.html


I am setting up a resort in Shimla, where hot water will be required 24x7 for about 8 months. The guest rooms are spread out in small cottages over a large area of land. As a result a centralised heating system will probably not work. So how best do I heat the water for a 24x7 hot water supply? We need to plan for guest rooms having 2/3 adults or 2 adults with 2 children, all having shower baths. I am thinking of using storage electric geysers, but cannot decide on the size. Would it make sense to use 2 geysers in each bathroom - say a 35 litre main geyser with a 15/25 litre auxiliary geyser. When the room is occupied by only 2 guests, only the main geyser is switched on, and when there are extra guests in a room, the auxiliary geyser is also switched on. I have also considered AOSmith heat pump geysers but they are costing about Rs 65,000 each for a 60 litre geyser. I think the payback period is almost 20 years. Another point to be kept in mind is that in winters, the tap water is bitterly cold, close to freezing. Would greatly appreciate your advice. Many Thanks.

Abhishek Jain (Mod)


Each individual will not need more than 15 lts of hot water even if they use shower. I think 30-35 lts should be more than enough as the water will get heated by the time 3rd person comes in for bath. I do not think you would need an auxilary geyser. You can try putting one 35 lts in one bathroom and do an experiment for 2-3 people taking bath immediately one after another. Try it in one room and then if it works then fit similar setup in all of them.


I suggest you to install solar water heater as feed water to your geyser- individual or common depends on the distance between cottages. Which will redue your eb bills by more than 65%. The payback period for geyser will be around 2to 3 years. - Prakash, Ooty


Ours is a two storied house with a single point for geyser on the terrace connected to 3 bathrooms - 2 bathrooms on 1st floor and 1 ground floor. We are 6 members. What capacity of geyser do you suggest? Also horizontal or vertical, was looking at AO smith

Abhishek Jain (Mod)

Because you have 3 bathrooms connected and it is possible that all of them may get used at any given time, it is better to go for a 50 lts geyser for this (assuming 15 lts is needed for each bathroom at any given time for shower bath).


I am planning to buy a Morphy Richards Lavo EM-6 for a family of 3 in Chennai. We take only bucket baths and only during winter. Will that be a good choice? Or would you suggest going for a different brand or a bigger capacity?

Abhishek Jain (Mod)

6 lts should be sufficient for chennai in winter if you prefer bucket bath. I have a 6 lts model in my bathroom in Mumbai and it works fine for bucket bath or short shower. Climate in Mumbai/Chennai will not get too cold in winters, so 6 lts should be sufficient.


Thanks Abhishek. Should I go with Lavo or Salvo? I couldn't find much details on the make of the two. Would like to have your opinion.

Abhishek Jain (Mod)

6lts is too small. From an energy consumption point of view the choice will not make much of a difference. Go for one that gives you flexibility to change water temperature as you can reduce your electricity consumption by reducing the water temperature from the geyser.


I am using pressure pump to send water to the bathrooms. So, what options.do we have in geysers that will work with the pressure pump. It is for two persons use in each bathroom.

Abhishek Jain (Mod)

You will have to check for the pressure tolerance level of a geyser before purchase. Many are designed to handle high pressure as in high-rise buildings, water pressure is usually high.


Hi Abhishek ,
I would like to buy a geyser for my home located @OOTY. Please answer me on these
1) Storage or instant which is preferred ?
2) What happens if we forget to turn off the switch
3) Bajaj or havells which service is recommendable.

Thanks in Advance.

Abhishek Jain (Mod)

Here is my response:

1) If it is for bathing, better go for storage. Electric Instant will not heat up fast enough. If you want instant then better go for gas geyser.

2) If you forget to turn off the switch, when water reaches set temperature, thermostat switches it off. But during the day, water looses heat and cools down and themostat again senses it and switches on the geyser. The process continues.

3) Depends on service at you local level. Cannot comment which one is better.


i wish to buy instant water heater...i dont understant which to buy....1L ot 3L...also which brand is good....havells or bajaj?

Abhishek Jain (Mod)

If it is for a tap on wash basin, then go for 1 lts. Else if you want more hot water, go for 3 lts. I think Havells is better.


Hi, I am confused between Havells Monza 15 ltr, Kenstar Aquafresh 15 ltr and Kenstar Jacuzzi 15 ltr. Could you help me choose the best among these? Is there any other heater which would be best in 15 ltr category? I have heard negative reviews about Kenstar servicing.

Abhishek Jain (Mod)

Havells has more energy efficient and feature rich models. So I would suggest Havells to you.


Thank you for the quick response!


Hi Abhishek
We have 2 bathrooms connected to 1 water heater point. N we have 2 family member using shower so what qty of storage water heater is right for us in terms of saving electricity n also what brand ..Please advice.

Abhishek Jain (Mod)

A 35 lts water heater should be good for you. You can look at these models:

AO Smith HSE-VAS-035
Morphy Richards LAVO DIGI35 or LAVO EM35
Havells MONZA EC 35 or MONZA TURBO 35


Hi abhishek
we taking bucket bath, would you please suggest which one water heater is good for use , electricity or gas for saving purpose .


Abhishek Jain (Mod)

Depends on what you use and if you have LPG without subsidy, then going for gas would be very expensive. You can go for a 10lts water heater or even a 6 lts water heater with higher kW rating. You can look at the top most efficient water heaters on this link: http://www.bijlibachao.com/top-ten-appliances/best-water-heaters-geysers-brand-in-india-by-standing-loss-and-size.html


I have 2 toilet in the apartment, 5 people will be using it ( with or without shower ), can say how many liter of water heater required, what will be usage of electricity , Can u refer which company deals efficiency of water hear.

Abhishek Jain (Mod)

Hi Srikanth,

In general a 10 lts water heater is good enough for bucket bath and 15 lts is good enough for shower bath. You can look at the top models on this link: http://www.bijlibachao.com/top-ten-appliances/best-water-heaters-geysers-brand-in-india-by-standing-loss-and-size.html


Hi I have a house connection load of 3KW is it fine if I install a 2000W -15 liter geyser

Abhishek Jain (Mod)

You will have to make sure that your total load running at any given time does not exceed 3 kW. Otherwise adding 2 KW geyser should not be a problem if your connected load is 3 kW.


Hi abhishek, I am staying in Pune , we are 3 adults +2 kids , we generally taking bucket bath. the gap between 2 persons bath is around 5-10 mnts so would you please suggest which gyeser or water heater we want to use, and also save electricity point of view...plz suggest thanks,Mahadev

Abhishek Jain (Mod)

You should go for a 15 lts water heater. You can look at the top most efficient ones on this link: http://www.bijlibachao.com/top-ten-appliances/best-water-heaters-geysers-brand-in-india-by-standing-loss-and-size.html

I think the ones from AO Smith, Morphy Richards, Ferolli or Havells would be really good.


what is the ideal brand for borewell water bathing and for family of 4 what should be the size of geyser

Abhishek Jain (Mod)

For Bucket bath 10 lts water heater is good and for shower 15 lts is good.

Abhishek Jain (Mod)

Racold, AO Smith, Havells, Bajaj, Ferroli, Morphy Richards, Venus all have good corrosion protection. You can go for anyone of them.


Dear Abhishek, I have Ferroli Calda 15. We knew the water heater stops heating when it reaches set temperature (thermostat) and re-start when the heater loses temperature. I want to know how many degrees of temperature drop is required to re-start heating. Please try to get the answer

Abhishek Jain (Mod)

Typically thermostats cycle on differential of 1 degree (source: http://www.explainthatstuff.com/thermostats.html ), but then there are thermostats available with adjustable differential as well. Truly depends on what the company has used.


Hi there!
I am the only one who will use geyser for shower bath. Which brand and capacity would you recommend for low energy consumption and long run usage? Could the same be also used for 2 adults in family, if not one? also, can geysers have settings for low high temperature as we use warm water for bath not hot. Thanks. :)

Abhishek Jain (Mod)

Hi Ahmed,

You should go for a BEE 5 star rated 15 lts water heater from AO Smith, Havells or Racold. You can use it for 2 people as well. You can look at the list of top most efficient geysers on this link: http://www.bijlibachao.com/top-ten-appliances/best-water-heaters-geysers-brand-in-india-by-standing-loss-and-size.html

Naresh Bogavaram

Hi Abhishek,
The service guy told me that, it doesn't matter whether we use 4 star or 5 star, if we are just using for shower. As star rating comes into picture for standing loss only. If we switch off geyser after use, does it make considerable difference between 4 star and 5 star?


Abhishek Jain (Mod)

Hi Naresh,

Your service guy is right in his statement. In fact not only for shower, but if you have a water heater and you optimize your hot water use in such a way that you do not leave hot water in the heater, then star rating will not matter much. Because standing loss will not be much if you do not leave hot water in heater for long. If you switch off geyser after use, then you should focus more on getting a model from a good brand with good corrosion protection and adjustable thermostat.


Hi Abhishek,

I want to choose between AO-SMITH and Rachold 15L water heaters, one has a standing loss of 0.451 and another 0.461. How much of a difference does this actually make? It feels too small a difference. Please guide me.


Abhishek Jain (Mod)

Hi Srikar,

Standing loss is amount of heat loss (in units of electricity) that can happen if hot water is left in the water heater for a full 1 day. This means that any model with standing loss of 0.451 will loose 0.451 units (electricity equivalent) of heat in 1 day if you leave hot water in it.

Frankly if you use up all the hot water efficiently, the standing loss will not matter at all. But then as you rightly guessed, the difference is too small.


Dear Abhishek, I have Ferroli Calda 15. We knew the water heater stops heating when it reaches set temperature (thermostat) and re-start when the heater loses temperature. I want to know how many degrees of temperature drop is required to re-start heating. Please try to get the answer.


Hi 4 memebers are there in my home, i want to purchase geyser, plz suggest company,model,capacity is best for me

Abhishek Jain (Mod)

Will it be used in bathroom? Will it be used for shower bath or bucket bath? If you will use it for shower bath, then 15 lts would be better else, 10 lts would be good enough.


Want to buy a gas water heater for house. I need a better model. Can anyone please suggest. we have instoshot which needed servicing lot of times.

Abhishek Jain (Mod)


Most leading brands have gas water heaters these days. Racold, AO Smith, Bajaj, Havells, Venus all are leading brands.


We also want to use the same tap for cold water usage with high force will it affect the geyser?

Abhishek Jain (Mod)

pipes for cold and hot water are usually different. So it should not affect the geyser.


We have 6 family members using 50ltrs of water each and there is 20 -30 min gap after each bath.we live in pune. We want to buy a storage geyser. Plz suggest me the right capacity geyser to save electricity.

Abhishek Jain (Mod)

If 50 lts per person total daily consumption or just for bath? As just for bath 50 lts is a whole lot of water. Ideally a bucket bath involves about 15 lts and shower bath involves 25-30 lts of water.


It is for 2 times bath daily for 6 person.


As Mr. Abishek said, you can go for 15 storage geyser. It is suffice. My recommendation for you is to go for Ferroli Calda 15 which is brand new and I found this better than all brands which are currently available in the market. I have installed 3 geysers at my 3 bath rooms and all 3 are working fine.

Abhishek Jain (Mod)

If 50 lts is for 2 bath then 25 lts for 1 bath. In that case a 15 lts water heater should be good enough for your use and electricity saving. You can look at top most efficient water heaters on this link: https://www.bijlibachao.com/top-ten-appliances/best-water-heaters-geysers-brand-in-india-by-standing-loss-and-size.html


1. Which type of connection tube is recommended for storage water heater ? SS tubes or Rubber tube (suitable for hot water upto 70 degree-Water Tech brand ) ?
2. If water re-filling in tank is cycle process, when hot water is withdrawn, then there will be reduction in temperate of hot water (set temperature) which is due to re-filling of cold water. Hence, we won't get hot water as per our set temperature. How to manage this to get hot water as per set temperature ?
3. When water become empty in Over head tank, the water heater won't get water re-filling. In such cases Heating element will be damaged if water is not there in the water heater tank. How to manage this ?
4. We noticed that the hot water flow from the shower is too slow. But, cold water flow is OK. Is there any problem with my newly installed 15 L geyser ?
5. We noticed that while bathing the temperature of hot water inside the water heater gradually reduces. (2 degree Centigrade reduction in every minute). Can we avoid this temperature reduction ? My set temperature is 50 degree centigrade. But, I am getting this temperature only for 2-3 min. Soon after, I am getting temperature only 35 degree centigrade by gradual reduction in temperature. Is there any problem with my new water heater ?

Please clarify above points.

Abhishek Jain (Mod)

The only thing that a water heater does is: heat water to the set temperature. It does not regulate the flow of water. The pressure of water flow (or rate of flow) will depend on the pressure in the system and the piping used. It does not have inbuilt system (pumps etc) to increase the flow of water. If you need that, then you need to put external pumps or increase the height of the water heater from the shower level.

Now to answer your questions:

1) SS tubes are more long lasting as compared to Rubber tubes (which can get damaged and can cause leaks). However, it is better to go for stainless steel flex connectors (as shown in this link: ) as they have stainless steel plus rubber insulation.

2) The water in the storage tank gets heated to 65-70 degrees. For home use you do not need water having temperature more than 40 degrees. So you will need to mix hot water and cold water if the temperature of water is more. The tank will get filled with cold water (unless you have something to stop it) when hot water is drawn out of the water heater. Some brands like Havells have models that prevent this mixing. But 99% models in the market do not have this feature. So the right sizing of water heater based on the need is very important.

3) I don't think emptying of overhead tank will cause damage to water heater, but it is better if you switch it off immediately, else you will waste electricity.

4) For slow water rate, you will either have to install a pump or increase the height of the water heater so that there is pressure difference.

5) 15L water heater is a bit small for shower bathing especially if you are used to long shower baths. Average water consumption for a shower bath is 25 lts (statistical average). Some people use more than that as well. If your usage is more then it is highly likely that you will get cold water after some time as a 15 lts water heater would take about 15-20 mins to heat water to its capacity. This is not a problem with your water heater, but more of a problem of undersizing the water heater.


Is there any minimum time or temperature drop required to again switch on the thermostat when observed a drop in temperature ? My Heater is equipped with digital display temperature panel.

Abhishek Jain (Mod)

There has to be some sensitivity for thermostat. How much is it, I am not sure about that.


I am using Ferroli Calda 15 L Water Heater.
How much electricity units will be consumed to heat 15 L water (one time). Inlet water temperature is 30 deg C. Hot water requirement is 60 deg C.
Pls comment on the same parameters of Ferroli Calda10 L also.

Abhishek Jain (Mod)

Formula is simple and as mentioned above:

Energy consumption = Volume of Water x Temperature Difference x 0.0012

so for 15 lts it would be 15 x (60-30) x 0.0012 = 0.54 units per round (15 lts) of heating
for 10 lts it would be 10 x (60-30) x 0.0012 = 0.36 units per round (10 lts) of heating. Additionally there would be some standing loss (as per specification of the model) which will depend on the time for which hot water is left in the water heater.

Typically standing loss value mentioned on the water heater is units lost per day. So if the value is 0.4 units, then it means that the water heater will loose 0.4 units if the water is left in the heater for the full day. If you do not leave water in the heater, it would be negligible.


Thanks for easy explanation. What is 0.0012 ?

Abhishek Jain (Mod)

The standard formula is m (mass) * cp (specific heat) * dT (temperature difference). We have converted mass to litre and multiplied it with specific heat and that's how we have come up with this number of 0.0012.


Can you please derive the formula by putting values for mass and specific heat ? I would appreciate if you can explain this as did for energy consumption calculation. What is meant by specific heat ? Whether the value of specific heat applicable to all capacity of water heater ?

Abhishek Jain (Mod)

Specific heat is explained well on this link: http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/spht.html

The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius. ..... it does not change with capacity of water heater ..... it is a constant value.

Specific Heat of Water is 4.19 KJ/Kg degree centigrade ( source: http://www.engineeringtoolbox.com/heat-work-energy-d_292.html)

1000 joules or 1 kJ is 0.000277778 kWh or unit of electricity (source: http://www.rapidtables.com/convert/energy/Joule_to_kWh.htm) ...... so converting 4.19 KJ/Kg degree centigrade to KWh/Kg degree centigrade would be 4.19 * 0.000277778 = approx 0.0012 kWh/Kg degree centigrade

So if you have 1 lts, that is equivalent to approx 1 kg water.

So to raise temperature of water from 30 to 40 degrees would be

1 kg x 0.0012 (specific heat in kWh/kg degree centigrade) x (40-30)

and that is where 0.0012 comes into picture.

The values does not change with capacity of water heater ... nor does it change with brand of water heater .... it is a universal constant!!


As mentioned in your point no. 2, How Havells can prevent mixing ? I've also noticed that they use Whirl Flow Technology for this. Do you have any idea how this technology works ?

Abhishek Jain (Mod)

I am not very sure on how this technology works. May be they close the incoming water source till the point the hot water in the heater is used up completely.


Thanks for your immediate responds.

But, I've very recently brought Ferroli, Calda, 15 L Water Heater.

1. Long lasting of SS tube is agreed. But, the seller recommends to have Rubber tubes (suitable for hot water) since, SS tubes sometimes may shock/leak electricity or earth to user. Is it true ? Shall I go with seller recommendations or ask only for SS tubes?

2. According to your point no. 5. post withdrawing of hot water from shower tap (approx. 4L) I am getting gradual reduction of the water temp. from 55 to 32 deg C (My set temp. is 55 deg C). Water with 32 deg C is unfit for hot water bathing. How to solve this issue ? My usage during shower bath is not more than 15 L.

3. Can't we get 15L of hot water from 15L water heater ? If no then, how much is minimum volume of hot water supposed to get from 15L Heater ?

4. According to your point no 3, during bath using water heater, if no water supply to water heater due to emptiness of Over head tank(Sintex-1000L) the heating element become dry due to heat and get damaged. However, we can not ensure the fullness of Overhead tank, all times. We come to know about the emptiness only If we observe no water supply from the tap during bath. After observing this only we can switch off the power. Before we switch off the power, the heating element will have no water hence, there are chances of damage to heating element due to dryness. Am I right ? If yes, do you recommend any preventive action to safeguard the heating element which is the heart of Water Heater ?

5. How long the 15 L Ferroli Calda water heater preserve the hotness of water?

Abhishek Jain (Mod)

Hi Bharath,

1) Shock happens when there is earth leakage in the wiring. Which is actually not good. You should always use RCD in your house to prevent electric shock. Here is more about RCD: https://www.bijlibachao.com/general-tips/why-is-rccb-necessary-for-your-house-rcd-electric-shock-residual-current-detectors-rccb-circuit-breaker.html

2) The only solution to have continuous hot water is to go for bigger water heater. I do not think you can solve it with your existing water heater (unless you have an option/thermostat to increase temperature from 55 to say about 70 degrees). I think Ferolli Caldo has thermostat to adjust temperature to 70 degrees.

3) Depends on how hot you actually call hot and what is the temperature of input/cold water. Typically one would need water at 39-40 degrees for bathing. Total volume of water from 15 lts water heater will be less in a cold city as compared to a hot city.

4) I do not think that heating element should get damaged in case if you switch off the power after few minutes if the tank getting empty.

5) Frolli Caldo is BEE 5 star rated water heater. It would have standing loss of about 0.45 units (kWh) per day. So in 1 hour the loss would be 0.45/24 = 0.01875 unit per hour. Which means it will loose 0.01875/(15x0.0012) = about 1 degrees temperature per hour. So if you heat water till 70 degrees and leave it in the water heater for 1 hour, it would become 69 degrees.


To add answer to my point no.4, To safe guard the heating element from damage when no water flow from the Overhead tank, the product is equipped with safety valve which controls not to permit water flow from tap (point of use). Hence, water will be always available to contact with heating element to prevent dry heating.

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