The rattling of teeth and shivering of the body in winters can only be stopped by a warm, relaxing bath. Thanks to a Water heater or geyser that helps us shower in the chilly winters!

While buying a Water Heater, we come across a variety of models. We find it tough to decide which one to choose.

It becomes even more difficult to decide whether we should choose a Storage water heater or an Instant water heater.

In this article, we’ll be walking you through the pros and cons of both the types of water heaters. It will help you choose which one is a better option.

First, let us have an idea as to what is an Instant and a Storage water heater.

What Is An Instant Water Heater?

As the name suggests, an Instant water heater is capable of heating the water instantly.

In other words, they are made for instant use.

These geysers have a low storage capacity of 1-3 litres.

They are small in size and don’t occupy a lot of space.

One of the main reasons why this type of geysers is so popular is that they provide hot water only as required.

You turn on the tap; cold water gets transferred to the tankless unit through a pipe. Either electricity or gas can be used to heat the water.


  • An instant water heater is a right pick for you if you are short on space in your house.
  • They are energy-efficient.
  • You don’t need for the water to get heated. You will be able to get the hot water as and when you need it. You have to switch on the system only.


  • Lack of storage may not be ideal for many people. If you use it in a bathroom, you wouldn’t be able to heat the water for entire family at once.
  • There doesn’t seem to be any power wastage but, they put a load on the entire system.
  • Installation charges are higher as compared to the storage water heaters. Repairing charges are also high.

What Is A Storage Water Heater?

Anything over 3 litres constitutes a storage water heater.

You get a constant flow of hot water until it is over.

Most of the water heaters in the market are storage models.


  • Installation charges are quite reasonable.
  • If the system tends to stop working, repair charges are not that high.
  • It can store a huge amount of water all at once. Once the water gets heated, you can use it for diverse purposes.
  • They are best to be used in bathrooms. You don’t need to switch on and off again and again as in the case of Instant water heaters.


  • They require larger space as compared to Instant water heaters.
  • Their lifespan is little lower than Instant water heaters.
  • You need to wait for a few minutes for the water to heat up.
  • Lazy bums.

Now that we talked about the pros and cons of both the types of water heaters, let us take you through a comparison between the two.

Time Taken for Heating Water

In Winters, the temperature of water in India varies from 4-21 degree Celsius.

If the input water is 15C, Instant water heater will heat the water to 60C within 2 minutes.

If water is 22C, it will take just 20 seconds to heat the water.

Whereas, Storage water heaters take more time to heat the water.
Flow Rate of Water

Usually, tap water flows at a rate of 3 litres/minute, and showers have a rate of 8 litres/minute.

If you have a 3-litre Instant water heater, the water will heat up as you empty the tank. Since showers have a higher flow rate, you don’t get water at a right temperature to bathe.

It means that if someone lives in a colder city, he/she won’t get a continuous flow of hot water. He/She would have to wait for some time.

Energy Consumed for Heating Water

Looking at the pros and cons, you may infer that an Instant Water Heater is the most ideal choice.

Since they don’t have any storage, there is no chance of heating extra water or wasting hot water. And there is less wastage of electricity. It sounds great!

But, the rate at which it draws electricity is quite high.

Therefore, a storage water heater may be rated 2kW, and an Instant water heater is rated 3-4.5 kW.

If 10 litres of water is heated in both the water heaters, the number of units consumed might be the same.

But, it puts more load on the entire system. Since an Instant water heater heats the water instantly, it draws more power from the system.

What Does This Mean?

It means that an Instant Water Heater may be good for an individual but is bad for the system.

However, if the usage of water is less such as in kitchens, wash basins, Instant geyser can be used.

These geysers might serve you well even in the bathrooms if you live in the southern part of India. The reason is input water temperature will be around 20C.

Otherwise, it is better to opt for Storage water heaters.

Final Verdict

There is nothing like buying instant water heater is wrong or buying a storage water heater is right.

Small water heaters have small energy loses.

Our intent should be to save water and minimise the wastage of water. For example, you can use a bucket instead of a shower or tub to take a bath.

Also, try to heat optimum water to save electricity.

By using Instant geysers, you may save money in the short run.

But, Storage geysers balance out the equation of power usage. They consume the same power over a longer period of time.