Advantages and disadvantages of instantaneous water heaters

Instantaneous water heaters heat water on demand instead of heating it up and storing it in a tank. You may not have heard of this option, or you may only know about it briefly: we will give you the advantages and disadvantages of this type of system.

We won’t go into the details of how a tankless water heater works here, but we refer you to our article on tankless water heaters for a more detailed explanation.

Instantaneous water heaters: main advantages

A virtually infinite supply of hot water

An instantaneous water heater represents an opportunity to save energy, as it does not heat the water in advance, so does not represent additional energy consumption when not in use.

Unlike a tank water heater, which heats the water gradually and continuously and stabilises once the water is heated, the instantaneous water heater, as the name suggests, heats the hot water in real time.

Since an instantaneous water heater heats the water as soon as it is required, the issue of having to save hot water disappears. This is the main reason why people choose to equip their homes with an instantaneous water heater

These points affect your comfort and your wallet: it also takes up much less space than a tank model. It also has a longer lifespan than a tank water heater (20 years lifespan compared to 10 or 15 years for its tank equivalent).

This type of installation also reduces the risk of bacterial proliferation, as it does not contain warm water, which is a breeding ground for bacteria such as legionella.

However, rest assured that regardless of the type of installation, the water in your water heater is kept at a high enough temperature to kill these bacteria, but this is one reason why you should not drink the hot water in your home.

Instantaneous water heaters: main disadvantages

Choosing the right model

Tankless water heaters have a few disadvantages that must be discussed in order to fully understand this system before purchasing and installing it.

We mentioned an infinite supply of hot water earlier, which can be a disadvantage if you want to save money on your energy bill. While the concept of a tank with a limited supply of hot water is no longer a problem, it can also lead to extra costs if you use too much hot water, as you are still paying for the electricity or gas that the heater needs to function properly.

On-demand water heating represents on paper an endless supply of hot water, which means that it continues to heat water as long as the tap is not turned off. In addition, this equipment may require you to modify your electrical outlet or make modifications to allow for a gas supply, which is another cost to consider.

To consider the usefulness of a tankless water heater, it is also important to understand that it heats the water to the temperature at which it arrives through the pipe between the municipal system and your home. During peak winter months, water arrives at your home at near freezing temperatures and heating it instantly can require a lot of power.

A tank-type water heater is based on its recovery rate (the number of gallons of water heated in an hour) and the size of its tank. For a tankless water heater, it is more a question of the number of simultaneous uses: some can only be used for one use at a time, at the risk of seeing variations in the temperature of the hot water.

An instantaneous water heater will cost more than a tank water heater and if you want to use it as your central water heater, it is strongly recommended that you consider a gas model, as electric models are less powerful.

In summary: a tankless water heater, efficient depending on the model

The tankless water heater is a convenient and space-saving system, but you will need to do your research to get the best unit for your home and hot water use.

A tankless water heater is more expensive to purchase and install than a tank water heater, but if you want to have an endless supply of hot water and save energy, it may be worth considering.

Remember, like so many things in our homes, the tankless water heater must be able to continue to do its job during peak winter full stops! Get a gas-fired tankless water heater if it is your central water heater and take the time to see how many hot water uses a tankless water heater can provide.