Electricity Saving Tips For Homes And Offices

Instant water heater/geyser: may be good for individual but bad for system

By on April 22, 2016

We recently got an email from a reader of Bijli Bachao saying that he purchased an instant water heater after reading our articles. This made us think: did we ever recommend using instant water heater to people? The answer was NO. Were the articles written in such a way that it came out that instant water heaters were better? May be! So we thought of writing this article that can give our understanding and take on instant water heaters. There is nothing like buying instant water heaters/geysers is right or wrong, but with this article we will provide our take on instant water heaters and the impact of using the same.

Water Heater/Geyser electricity consumption

As we presented in our previous article: Choose the right sized water heater/geyser for electricity saving, it is important to choose the right sized water heater because the amount of electricity used by water heater depends a lot on the usage of hot water. The lesser the hot water used, the lesser is the electricity consumed. Also lesser the water you heat, lesser is the electricity consumption. Thus it is important to choose the optimum sized water heater that suffices your needs. The smaller the size better it is. Although smaller the size, higher will be the rating of the water heater. Also it is better to switch on the water heater before the use and switch it off immediately after.

Instant water heaters

Looking at the suggestions above, instant water heaters come across as the most ideal solution as they do not have any storage (so no chance of heating extra water or wasting hot water) also they have to be switched on before use and switched off immediately after. The electricity unit consumption is apt and there is very less wastage. From an individual’s perspective it sounds great.

Drawbacks of Instant Water Heaters

Because the instant water heaters have to provide water at the desired temperature, the rate at which it draws electricity at any moment is very high. So a storage water heater may be rated at 2 kW, an instant water heater is rated at 3 to 4.5 kW. So if 15 liters of water is heated in both, although the units consumed may be the same, but because instant water heater heats it immediately, it draws more power from the system i.e. it puts more load on the system.

Imagine a city where most people use water heaters between 7 AM and 10 AM in the morning and most water heaters are switched on during this time. If most of them are of 4.5 kW then the infrastructure required to handle the same will be huge and if the infrastructure is not there then grid failures (similar to the one happened in North India in 2012) can happen again. There will be sudden need of a lot of power. Instead if most systems are 2 kW systems, it may take time to heat water, but the system will not be strained.

Personally for an individual, the connected load of the house will increase by 2.5 kW (4.5 – 2) and may cost additional money in terms of fixed cost. So the savings in energy cost may get transferred to fixed costs.

Our recommendations

We always recommend saving water and using lesser water for all purposes. More water is required if you take bath in shower or tub (about 25-30 lts), bathing using a bucket uses lesser water (about 15 lts). A 6, 10 or a 15 lts storage water heater is mostly sufficient for such use. In places that are cold or extremely cold during winters, a 15 lts water heater may be sufficient, whereas in places where the room water temperature is not too cold, a 10 or even a 6 lts water heater may suffice.

If water heater is to be used in kitchen and usage of water is less, a 6 or 10 lts storage water heater may be good enough. The intent should always be to heat optimum water to save electricity.  Smaller water heaters also have smaller energy losses and thus provide ideal water heating. Please note that there are few models of 6 or 10 ltrs storage water heaters are also rated at 3 kW (and not 2 kW). These are again not recommended from power system point of view.

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Instant geyser using 4.5 kW will heat up the electric wiring of home and may lead to rewiring after an accident. This will end up in expenditure & inconvenience.


I want to buy a gyeser for kitchen upto 5 ltr which 5 star . pl give option

Abhishek Jain (Mod)

Hello Mr Saini,

BEE star rating for water heater starts with volume of 6 lts and above. There is no star rating for models with lesser capacity.


Can someone suggest me which type of geyser to go for to be used with a shower panel?
It has about 6 jets and might require atleast 15-20 minutes of instant heated water during bath.


My 35 litres water heater (brand: Usha Shriram) gives just only 15 litres of very hot water after 30 minutes of heating. After that, the water temperature falls sharply down to lukewarm water. What could be wrong? Should I not be getting 35 litres of hot water - not just 15?

Abhishek Jain (Mod)

To heat 35 lts of water (to a preset temperature of 65-70), any water heater (not just Usha) would need about 2 units (or kWh) of electricity. Most storage water heaters are either 2 kW or 3 kW. A 2 kW system will generate 2 kWh in 1 hr and a 3 kWh system will do the same in 45 mins.

So you will not find any water heater in the market that will heat 35 lts water heater in 30 mins. If you are using it for a bathroom, then the ideal size would be 10 lts (for bucket bath) or 15 lts (for shower bath). 35 lts is too big and would take time to heat (any brand).


How much quantity is better for 4 members of a family?
Which geyser is better instant or storage?

Abhishek Jain (Mod)

Size of geyser depends on the single maximum usage. So for e.g if everyone prefers bucket bath, then 6-10 lts is good enough in most cases (if you live in a slightly hotter location like Mumbai then 6 lts is good enough, but for a colder city like Delhi 10 lts would be good). Similarly, if some people prefer shower bath then 10-15 lts is good (similarly 10lts for Mumbai and 15 lts for Delhi).

An instant geyser is good for short use. So it will be ideal for kitchen usage and not for a bathroom.


3/L written on a water tank. Then what mean of this 3/L for water tank.

Abhishek Jain (Mod)

It has a storage capacity of 3 litre.


I am across these geysers from Stiebel Eltron (Germany's leading geyser manufacturer). The geyser costs 18000 but occupies very less space. Since both my bathrooms are close to each other I will need to install only 1 geyser instead of 2. These instant geysers do not have any specific capacity but the company says that it can provide unlimited hot water for normal shower (not rain shower) . They also talk of significant power saving. Only heard pros not any cons. Has anybody used them or researched about them

Abhishek Jain (Mod)

Can you provide an online link to the product so that it can be analyzed? Usually any geyser with less water storage consumes less electricity (so instant geysers consume less electricity as there is no standing loss). But then total electricity consumption depends on the volume of water that is heated. If you heat 100 lts the electricity consumption will be more as compared to if you heat 50 lts. And you can get unlimited hot water if the heating element has high wattage. Ususally instant geysers have heating element of 3 kW, but the one with 8-12 kW can certainly heat faster. Most gas geysers available in market have heating capacity equal to 12 kW and thus gas geysers also give unlimited hot water. And are energy efficient too. The only major care that you have to take with gas geysers is that you have to make sure that installation is safe.


https://www.aquagreensolutions.in/faq This link has all the FAQs. Clearly this is not a gas geyser. Seems to be a completely different product.

Abhishek Jain (Mod)

Their single phase models are 6 to 8 kW models. Regular instant water heaters are about 4.5 kW. So 6-8 will certainly heat faster. But that will increase the connected load of your house. So the pros are:

1) You can get instant hot water. May work with shower as well (however I doubt it will work with rain shower).
2) Your electricity units consumption will be little less. Not very less if you usually do not leave hot water in water heater. However, if you leave hot water in water heater then this can make it significantly less.
3) Your energy charges on electricity bill will come down.


1) You will have to get your connected load increased because one single water heater will put 6-8 kW extra load on the system as compared to 3-4.5.
2) Your fixed charges on electricity bills will increase because you increase connected load. One has to analyze if it really gives benefit by decreasing energy charges but increasing fixed charges.

This is not a gas geyser but gas geysers that are tankless are far more economical as well as energy efficient.


Thanks Abhishek for your clarifications.


hey abhi

Kenstar Hot Spring KGS10W5M-GDE 10-Litre 2000 Watt Storage Water Heater,
Kenstar is good brand to buy?
is it good to buy for 4 member's family?

Abhishek Jain (Mod)

Kenstar is a good brand. You can certainly go for it. Also size of water heater depends on the volume of water required for single maximum usage. So for e.g. if all the members in your family prefer bucket bath, then 10 lts is more than enough. For shower bath, 15 lts is good enough. If you have a tub then you need bigger water heater.


Which brand of instant electric heater can receive pre-heated hot water of 60-80c without any problem?
My builder has provided roof-top solar heater on building terrace which works well except in winter and rainy months, when hot water is just luke warm. If I install an instant electric heater between the hot water line and the mixer unit I should get hot water in winter also, but the electric heater inlet will receive 70-80C hot water in summer months (when the heater will be switched off). Will this damage the heater?

Abhishek Jain (Mod)

Hi Ajay,

Most top brands can easily handle 70-80 degrees because these water heaters themselves heat to that temperature. You can look at AO Smith, Racold, Havells, etc. They all can handle that temperature.


I live in Bombay and we are a family of 3. I require a geyser for Bathing (Shower) and Kitchen. Shall i go for a Storage or Instant? Also please let me know the capacity. Thanks

Abhishek Jain (Mod)

Ideally size of geyser should be based on single use requirement. For shower for a single person 15 lts is good enough. Usage in kitchen should be less. If you are planning for separate geyser then 15 lts for bathroom and 6 lts for kitchen should be goo.


Hello Abhishek, I am from Bangalore and for my house, I am installing pressure pump at the main to ensure adequate pressure in shower panels of my bathroom. I have two issues:
1. Should I install normal or pressurised solar water heater - The plumber is saying that in order to get adequate pressure for hot water, I should install the latter.
2. Will pressure continue to persist once I combine the pressurised solar water heater with storage geyser - I will need to put storage geyser in bathroom so wasn't sure if the pressure of hot water getting into the geyser will persist as the hot water will come out of it into the shower panel.
FYI, I am also putting a water softener before the main.


its better to put this gyser outside of the washroom as it emit gas which can unconcious anybody, as my daughter became unconscious due to leakage of gas into wash room so avoid this or put the stuff outside of the washroom thanks


i want to purchase a instant heater for shower needs for a family of 4 members
i am confused about what capacity i should buy
also plz tell me if we have to wait for hot water during bath in instant water heaters

Abhishek Jain (Mod)

Instant water heaters are only 1 or 3 lts. And they are not good for bath. So I would suggest you to not go for an instant water heater.


i want to purchase a geyser for my family of 4 members but i am confused with 6l and 10l. can you suggest which one will be good for me??

Abhishek Jain (Mod)

Depends on the climate in your city and the method that people in your house prefer for bathing. In general we suggest 10 lts water heater for bucket baths and 15 lts for shower bath. If the climate in your city is hot and people mostly use bucket bath then 6 lts would also work. But 10 lts is safe in general. You can look at the list of top ten 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 Abhishek,
I am basically confused for Instant Water geysers.Since they cost less,around 1500-2000 Rs, 'am planning to buy one. I generally use 20-22L ater during my shower usage.
But the query is,Do they provide me a constant flow of hot water during my shower use in bathroom...?


Sir This is yalli marketing from madurai sun water heater manufacturers
If you want please contact 9787580123

Abhishek Jain (Mod)

Instant water heater will not provide constant water flow of hot water for shower. You will have to go for bigger storage water heater for that.


i stay in bmby, and we are family of 2.Previously we had a 3l geyser, but now after reading the discussions, i am confused for 3l or 6 or 10.

the usage is very less, in a bucket we put 2/5 hot and 3/5 cold.

and 2/3 is what we need to take shower.

What do you suggest and what brand


Don't put your useless AD here.....

Abhishek Jain (Mod)

If you were satisfied with 3L geyser then I would say stick with a 3L because it will be more energy efficient. If not then for bucket bath in bbay 6 lts is good enough. For shower bath 10-15 lts is good depending on how long you use shower. Racold, AO Smith, Bajaj, Havells, Morphy Richards, Venus are some good brands. You can look at the list of top models on this link: https://www.bijlibachao.com/top-ten-appliances/best-water-heaters-geysers-brand-in-india-by-standing-loss-and-size.html


1ltr vs 3 ltr (instant geyser) What is the difference between 2 in terms of pros and cons????

Abhishek Jain (Mod)

1 lts instant geyser is good to be used for taps and wash basins where the water requirement is less. You will just wash hands or say use it while shaving, etc. 3 lts would be good for slightly longer use say in kitchen for washing utensils or for washing vegetables. The longer the instantaneous use of water (or more the use of water in one go), the storage capacity needed increases.


Which is more energy efficient 1L or 3L?

Abhishek Jain (Mod)

1L as it stored less water.


i am planning to buy geyser, please advise , instant geyser or storage geyser, we are small family, if power cut at the time of use, it is very difficult to kitchen, we are staying i n delhi

Abhishek Jain (Mod)

Do you want it for kitchen or for bathroom? In Delhi if you want it for bathroom then 10 lts water heater is good for bucket bath and 15 lts for shower bath. A 3 lts instant water heater may work for kitchen but will certainly not work in bathroom.


Hi are the new air heat exchanger water heaters more efficient than storage water heaters. Im talking about this one from AO Smith. https://www.aosmithindia.com/water-heaters/air2heat-water-heatersgeysers/hpw-80

Abhishek Jain (Mod)

These are heat pumps and are far far better than regular storage water heaters. These are just like air conditioners as they use refrigerant to take heat from air and heat water. But they consume a lot less electricity as compared to regular water heaters.


I'm looking for a geyser to use tor my bathtub. what size do you suggest ? also vertical or horizontal?

Abhishek Jain (Mod)

For bath tub it should be 25 lts. Vertical or horizontal depends on the setup you have. If you can fit vertical then you will get lot more options as there are few options in horizontal.


HI Abhishek,

I am planning to put an instant water geyser with a fully automatic washing machine. Is is workable.



Moreover WM don't accept hot water

Abhishek Jain (Mod)

I would say better buy a washing machine with inbuilt heater. I am saying this because washing machines need optimal water pressure. And then if you want constant flow of hot water from instant geyser, you will have to significnatly reduce the flow of water.


Hi Myself Rahul Raghav From Gurgaon.

I wanna buy two Geysers for three members n two bathrooms, using basket. Which types should i go with instant water geysers of storage water geysers & what should be capacity to use...??

Abhishek Jain (Mod)

In Gurgaon, do not go for Instant geysers. Go for 15 lts storage geyser. It would be safe.


why, is there any specific reason behind that ...??

Abhishek Jain (Mod)

Hi Rahul,

Firstly 6 lts water heater is not classified as instant geyser. Only 1 and 3 lts water heaters are classified as instant. And the reason I do not suggest instant is because you will not get sufficient hot water for bathing if you go for 1 or 3 lts instant geyser. More on it on this link: http://www.bijlibachao.com/water-heaters/should-you-buy-instant-water-heater-for-your-bathroom.html

As for 6 lts water heater, you can certainly go for it. But you may not get high wattage heating element in 6 lts heater. It may work out for bucket bath as a typical bucket just fills 10 lts. But winters in Gurgaon would be really cold and if two people use the water heater immediately one after another, you may not get sufficient hot water and that is why I suggested a bigger one. You can certainly go for 6 lts water heater. But if there are electricity issues, then it will be same for any water heater. Will not matter if it is small or big.


basically I'm living in a village there is light issue, so that's y i wanna buy Instant geysers of 6 ltrs. ... Now What do u suggest ..?


Is this a good geyser for 3 person family?
V-Guard Sprinhot Plus 6-Litre 3000-Watt Water Heater

Abhishek Jain (Mod)

depends on where you are and how you plan to use it. If you use bucket bath and do not live in a city with extreme cold weather, then it will work. Else it may not.

Udayakumar Palani

Please help me in choosing a brand/model in Instant water heater.

Abhishek Jain (Mod)

You can go for AO Smith, Racold, Havells or Bajaj instant water heater.


If same volume ( Say 30 litres) of water is used, then which will same more electricity
1. 3 litre instant water heater with 3K Watt
2. 6 litre storage water heater with 3K Watt
3. 6 liter storage water heater with 4.5 Watt

Abhishek Jain (Mod)

All will be same.


Finally decided to get Instant Water heater instead of Storage living in Mumbai

Which Instant heater should i go for Shower Bath electrician guy was telling me to go for 4KW but what storage and brand and model ?

Abhishek Jain (Mod)

You will need high wattage instant heater to make it really work for a shower bath. I would suggest that you read this link: https://www.bijlibachao.com/water-heaters/should-you-buy-instant-water-heater-for-your-bathroom.html

We do not have data on instant water heater to suggest something to you.


Hi, I want to know if buying an instant water heater of 3 ltr for 2 people who use a bucket and require 6-10 ltrs of hot water (total 15 ltrs warm water) having 3kw will be good enough to give out that quantity of hot water. Will 4 or 4.5K be better in such cases. As i live in mumbai the weather is usually hot and tap water is usually room temperature. I am confused between havells, crompton greaves and bajaj models of 3 ltrs. I have also heard remson is a excellent choice but it usually has 25 lts storage which is too big for me and i am not sure if remson has safety features as my parents are both aged and may forget to switch off the power sometimes. I am also unable to find BEE ratings for instant water heaters. does the govt not give BEE ratings to instant water geysers?? Thank you bijlibajao team just for taking time out to help out the average indian.


I would recommend a 6 ltr. storage type heater as now a days it comes with insulated storage tank and temperature setting knob which together will help you to save on electricity. Also the element is of 2 KW only which wont creat any problems for your wiring. Also the failure rate of instant heaters are more if you are living in high rise building. A storage type heater uses as low as 0.4 unit/24 hrs stand by power if you forget to switch off the heater.

Abhishek Jain (Mod)

BEE star rating is not available for Instant Water Heaters. It is only there for storage water heaters. I think an instant water heater can work great if you live in Mumbai and prefer buckets. Even a 3 KW heater should also work. Havells and Bajaj are good brands. You can choose anyone of them. Instant water heater can be great energy saver for you and I would not recommend you to go for 25 lts model.


Hello !!
I am planning to buy a Instant water heater (Racold 3Ltr) for my home use.
I have a big confusion weather instant water heaters will cause any health problems for new born baby's..
Can some on help me on this..

Thanks in Advance !!

Abhishek Jain (Mod)

There is not much difference between storage and instant water heater. Instant just heats faster. As long as water is not too hot, I do not think instant water heater should cause any health problems. Make sure that you collect water in a bucket and mix it with right amount of cold water so that temperature is just right for your baby.


We take some hot (boiling) water , mix it with cold water and use for bathing purposes. Also, while during bathing, we may even take additional hot water and mix it with cold water and use. Storage or instant water heater should be used ?


hi plz tell the difference between 1 ltr instant geyser and 3 ltr instant geyser?

Abhishek Jain (Mod)

The main difference as the name says is in storage. 1 lts one will have storage capacity of 1 ltr and 3 lts one will have storage capacity of 3 lts. The other difference that comes is that 3 lts one will come with a 3 kW heater while 1 ltr models have 3 or 4.5 kW heaters. The 4.5 kW heater will heat faster as compared to 3 kW heater. You can read more on instant water heaters on this page: https://www.bijlibachao.com/water-heaters/should-you-buy-instant-water-heater-for-your-bathroom.html


Which consumes more electricity? 3 ltr water heater or 1 ltr water heater? Both V-guard 1 ltr and 3 ltr water heaters consumes 3kw power as per specifications

Abhishek Jain (Mod)

It will depend on the amount of water you use. It is not dependent on the size of water heater. The size will just change the standing loss and standing loss comes in picture when you leave hot water inside the water heater. You can read more about it on this link on our website: http://www.bijlibachao.com/water-heaters/choose-the-right-sized-water-heater-geyser-for-electricity-saving.html


hii my self jaydeep. i am living in Ahmadabad. i want to setup a instant 3 l water heater in my bathroom. pl. suggest me the best 3 L instant water heater. i dont want any storage water heater.

Abhishek Jain (Mod)

Hi Jaydeep,

Havells, AO Smith, Racold, Bajaj, Ferolli are some brands that typically have high energy efficiency models in water heaters. So you can go for a model from any of these brands.


hi my self sandeep. I want to buy a water heater . I am living in join family with separate bedroom attached with bath. I am confused whether to buy instant water heater or storage one. please guide.

Abhishek Jain (Mod)

Hi Sandeep,

Instant water heaters are good when you use them for taps for washing hands or washing utensils or usage where the water use is less. If you plan to buy a geyser for bathing, then it is better to go for storage water heater.


Also i want to ask when its an instant geyser n nt storage geyser then what difference does it make, i mean b/w 3 or 1 ltr ?


Hii, we are a family of 4 people 3 adult n 1 chil in Delhi. Should i go for a 3 ltr instant geyser or 1 ltr? Consumption is just bucket bath on morning.

Abhishek Jain (Mod)

Would not recommend instant water heaters of 1 or 3 lts in Delhi as the climate gets quite cold over there. For bucket bath, better go for 10 lts one. You can check the top most efficient ones 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 am from Bangalore and use Solar Water Heater. However, 60 - 75 days (not continuous) in a year Solar will not work due to weather conditions. I would be requiring water heater during this time. We are family of 4 (3 adults + 1 Kid). Usually it would be bucket bath. Please suggest whether instant would be suitable or storage. If storage what capacity should I opt. Also please advise few geysers.

Thanks in advance.


Hi, can you please advise me


I want to buy 10 Leter Geyser not preferably instant but it must be more reliable and energy efficient. Please suggest which will be the best option Morphy Richards or AO Smith or anyone else??


I am Ajay from New Delhi. I need to buy water heater & need your guidance for the same.
Our usage of water heater is restricted to Bathing only [Shower & bucket use] We are two members.
What should I choose ?

Instant or Storage geyser and with what capacity?

Abhishek Jain (Mod)

Hi Ajay,

A storage water heater with 15-25 lts capacity would be better in Delhi especially if you use shower. If both of you will use it immediately one after another then a 25 lts would be better. Climate is quite cold in Delhi in winters.


Thanks Abhishek


can you guide me... its an confusion electric heater is good enough or investment in solar water heater is good option. as we consume hot water for maximum 4 months as belongs to Ajmer Rajasthan

Abhishek Jain (Mod)

Hi Rajiv,

If you consume hot water only for 4 months then I assume that those are the coldest 4 months of a year. A solar water heater may not be very effective in winters and you would need additional electric heater. And thus I would suggest that you go for electric heater.


And what is good.. Instant heating system or storage type of system... One more thing can we make assumption of electricity uses for 5 star rating 15 ltr storage and 5 star rating 3 ltr instant heater for a bucket...

Abhishek Jain (Mod)

Well it depends on usage. Instant heating system can be more efficient as it does not have much storage and thus heat loss will be less. Storage ones will have more heat loss. But instant water heater will not work well if you use it for bathing in Rajasthan. Because it has less storage and it does take some time to heat water, it may not work as you may expect. For extreme cold in Rajasthan a 15 lts water heater would be good in Winters.


the tap water in bangalore is very cold especially in winter. what geizer can we buy with temperature control from say, 30 degrees to say 50 degrees centigrade so that we can wash our hand straight on the taps

Abhishek Jain (Mod)

Hello Mr Natarajan,

If you are looking for something for tap water (and not for bathing) then an instant water heater of 1 lt would be great for you (if you keep tap open for long then you may go for 3 lts one).


as a senior citizen i face the problem of washing my hands in cold water. by tapwater i meant water say at 20 /25 degrees. what i want is water at say 32 degress for directly washing hands instead of mixing hot and cold water etc. and 36 degrees for washing my plates,mugs etc. is there any geizer with adjustments at such low heat. thanks for such immediate response

Abhishek Jain (Mod)

Hello Mr Natarajan,

If you go for a geyzer with temperature control (thermostat) then you can adjust the settings as per your comforts. Some of these might be good for you: http://www.havells.com/Product.aspx?s=122


We are 2 adults and 1 child and uses shower. My son likes to stay in water for little long. Should I got for instant water heater or storage type? I currently have 35 litres storage type and want to change it now.

Please advise.

Abhishek Jain (Mod)

Hi Varun,

Instant water heater would not give hot water for long unless you are in a place that does not get too cold in winters. Instant water heater may not work well with Shower. You would need storage. A 15 lts water heater is usually good enough for shower. But if you like long bath then max 25 lts should be good enough.


This is Balaji from Bangalore. Since our solar water heater went down, we started using the 3L instant water heater. Since then, the electricity bill has doubled.
Meanwhile, we have a newborn baby in our house and we require lot of hot water for both mother and baby throughout the day.
In this scenario, I'm wondering if it would be better if I replace my instant heater with a storage type.

Thanks for the advises.
Best Regards,

Abhishek Jain (Mod)

Hi Balaji,

Instant water heater should not cause increase in electricity bill as electricity bill depends on amount of hot water you use. If your hot water usage has increased then certainly your electricity bill will go higher. But a storage type water heater would not help in reducing electricity bills if your hot water usage has increased.


Hi Bijli Bachao Team
First of all thanks for such an gr8 initiative. Energy conservation / going green is need of the hour. Its quite useful for many ppl. Thanks again.

Myself Sandeep M. from Mumbai's Western Suburbs. I need to change our old 1 litre 3kw Instant water heater & need your guidance for the same.
Our usage of water heater is restricted to Bathing only [bucket use] We are 5 elders & 1 four yrs old kid & our usage is around approx. 100-130 litres of hot water daily maximum would be 150 litres.
Instant water heaters is preferred as there is hardly any space to fit large storage heaters. Gas heaters skipped due to space issue as it requires proper ventilation.

What should I choose ?
3 liter Instant or 1 liter instant Heater?

Suggest me some energy saving Instant Water Heaters asap as need to fix it by next 2-3 days.

Thanks & Regards
Sandeep M.

Abhishek Jain (Mod)

For bucket bath in Mumbai, 3 lts instant water heater should be good enough.


What will be energy consumption?
Will 3 litres instant water heater save some energy compare to 1 litre while heating faster or its otherwise please elaborate.


Abhishek Jain (Mod)

Hi Sandeep,

Electricity consumption of water heater depends on volume of hot water you use. As the volume of hot water will be same in both the cases (as with small volume water heaters, it is less likely that you will leave hot water lying in the water heater), electricity consumption will almost be the same in both. Also as both are small water heaters, standing loss (loss of heat due to hot water lying in the water heater) will be very less.


I installed 1 litre 3kw racold prono neo.
Due to poor rainfall there is water shortage in Mumbai so had to choose this as the water will also come from storage tank over loft.

Thanks for your help.


Hello BB Team,

This is Saurabh from Mumbai, we are a family of 5 adults n water usage 70 ltrs approx. n looking for small size gyeser...pls suggest me which type.. instant or storage..which brand...n size of gyeser to buy...

Thanks in advance..


Does it mean that a higher wattage instant geyser will give more hot water ? Comparing a 3KW instant geyser with a 4.5KW geyser. Will the 4.5kw one give hot water for a longer duration ?

Abhishek Jain (Mod)

Higher wattage geyser will heat faster. It will not give more hot water. Heating rate will also depend on the rate at which you draw water from instant geyser. If flow rate is high, then you need a higher wattage geyser so that it can heat faster. If flow rate is low, then low wattage will also be fine. Finally as far as electricity units consumption is concerned, it will depend on the volume of hot water you use. If you use 20 lts, then the unit consumption will be same for both 3 kW and 4.5 kW, however 4.5 kW will heat it faster.


Good comparison. Good Suggestion.
I also read your reply of Srinivas G question. Still i want your suggestion.
We are 5 (2+3kids). Am using solar heater system. But in extreme winter at my city Baroda, after 3 person am not getting hot water so want to connect with solar system in master bedroom for bucket bath. Which one is good for me Instant or Storage ? if storage then capacity ? Can you pls suggest me 2 brands with usage style ?

Abhishek Jain (Mod)

Hi Iresh,

A 10 lts storage water heater would be good for you. You can look at the top models of 10 lts on this link: https://www.bijlibachao.com/top-ten-appliances/best-water-heaters-geysers-brand-in-india-by-standing-loss-and-size.html


Your review on instant electric water heaters shows Morphy Richards Lavo EM 6 model on the top however I am not able to trace this model to buy online even on the Company's web site. Can you please help me locate the product for Purchase decisions ? I am located in Ahmedabad Gujarat and even a address of Company's authorised both for sales and service outlet may help if the same is not available on web shopping. Please guide.


Please suggest on what to select so that power consumption is less and the choice to be economical and serve are need :). Confused on what to choose between Geyser or Solar water heater connection for our new house in Bangalore.Thanks in advance.

Abhishek Jain (Mod)

Solar Water Heater is a great choice in B'lore.


hi iam krishna rao from vizag, i want to use two water storage geysers for master bedroom (two adult)and children(two child) bed room for shower and bucket bath. please adivce me which brand and capacity of heater is better to us.

Abhishek Jain (Mod)

Hello Mr Rao,

If you use shower bath then the water usage would be high (25-30 lts). In that case a 15 lts water heater would be better. You can look at these water heaters for your bathrooms:

Ferroli Caldo.15V
USHA Aquagenie 15L


In Kolkata which water heater will be the best for 6time*10ltr hot water in a day?and how much amount will come for this usage?

Abhishek Jain (Mod)

Hi Vishal,

Any 6 lts water heater can give you 10 lts hot water suitable for bath. For 6 lts you can look at these models:

BAJAJ Majesty 6 GPU
Ferroli Mito.6
AO Smith HSE-SBS-006
AO Smith HSE-SDS-006
AO Smith HSE-SAS-006

If you use it 6 times then you will heat 36-40 lts of water in a day. For the same you would end up using 1-1.2 units of electricity per day.


I have a 10 year old storage type electric geyser. Nameplate says 15 Litres & 3 kW. It does not have any BEE stars on it probably because it ages from before the rules came in.

What I want to estimate is how much savings could I potentially get by replacing this old heater with a new heater that is rated, say, 5 stars? What's the best way to calculate this? Currently load cycle on this geyser is approx. 45 minutes everyday. Unit cost is Rs 7 / kWh approx.

But even current unit does not always stay on for 45 minutes every day because internal thermostat will cycle it on & off.

I see online that a 5 star A O Smith Unit for 15 Litres shows a 2 kW power. But will the on-off duty cycle be identical to the existing unit to compare power consumption? I want to estimate payback period since this new unit costs approx Rs. 11,000

Abhishek Jain (Mod)

Hi Rahul,

Electricity consumption of water heaters depend on the amount of water heated. The time for which it is switched on is less important. The insulation of water heater defines the standing loss (or heat loss) and BEE rating is done on standing loss. If standing loss is more star rating will be less. However standing loss in general is less than 1 unit of electricity. You may read more about all this on our article: https://www.bijlibachao.com/water-heaters/choose-the-right-sized-water-heater-geyser-for-electricity-saving.html

So if the amount of hot water used remains the same then the savings will only be on standing loss difference. And it will be difficult to tell the standing loss value of your existing water heater.

As far as power rating of water heater is concerned, a 3 kW heats faster than a 2 kW. Otherwise electricity consumption is not dependent on that.


Thank you. To illustrate this better, can you show a calculation of payback on geysers? Say replacing a 2 star with a 5 star. With typical usage values. What's the payback? I wanted to get a general idea.

Abhishek Jain (Mod)

Hi Rahul,

Electricity consumption of water heater = Amount of electricity used to heat up water + Standing Losses.

Now assuming you heat the same amount of water using both 5 star and 2 star. The electricity used by both to heat up water will be the same.

Again let us assume that you leave hot water standing (stored) in both the water heaters for the whole day. Then the only difference would be the difference in standing losses.

The standing loss of most efficient BEE 5 star rated water heater of 15 lts is 0.426 units (or KWH) per day. That of most inefficient water heater is 0.681 units per day. The difference between the two is 0.255 units per day. So in a month the total savings would be 0.255 x 30 = 7.65 units. If you are in Mumbai where the tariff is highest (about Rs 10 a unit), then in a month you save 7.65 x 10 = Rs 76.5 per month.

If your water heater is not start rated and the standing loss is much higher (say 0.826 units) then the difference would be of 0.4 and monthly it would amount to 12 units (or Rs 120 if in Mumbai).

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