Boiler, water heater or immersion heater: which is best for your home?

Heating is only used in winter, but we need hot water all year long and there are broadly three ways to achieve this. It is only natural to be unsure which to choose: boiler, water heater or immersion heater , the three most common types of equipment.

We help you understand in which situations each of them is most recommended.

• Boilers: they can be natural gas or fuel oil. They serve both for heating the house and for hot water.
• Water heaters: can be natural gas, butane or propane. They provide hot water only.
• Immersion heaters: they work with electricity and provide hot water only.

Boiler: if in addition to hot water you need heating

If you need hot water and heating, your best option is a regular gas boiler .

If you are thinking of installing radiators or underfloor heating, a boiler is also the best solution, since it will provide you with water and heat practically instantaneously.

The boilers most commonly used are natural gas with condensation technology. They are able to make use of the latent heat in the combustion gases to achieve yields greater than 100%. What does this mean? It means you’ll save up to 30% on your gas bill.

If you want to install a boiler in your home remember that you’ll need a natural gas outlet and you’ll have to have it installed. If you’re not prepared for the expense and disruption this inevitably involves, you’d better opt for another heating system.

Another aspect to consider is the output of the boiler. You don’t need as much for an apartment with a single bathroom and a kitchen as for an apartment with several bathrooms, a large kitchen and many rooms. Reckon on 115 W per square metre .

To give you an idea, the most common outputs are 23-25 kW, enough for a standard home. But if your house is very large or you live in a cold area you can increase the margin and opt for 30-35 kW.

“Multiply the square metre area of your house by 115. The result is the capacity that your boiler must have.”

Water heater: only for water and if you already have a gas outlet

If you only need domestic hot water, the gas water heater is a recommended option.  Smaller in size than boilers and immersion heaters, they can heat all the water that enters the system as long as their capacity is not exceeded .

In other words they heat cold water by means of a gas combustion circuit (normally natural gas, butane or propane). There are also electric heaters , but they are not particularly efficient.

But water heaters are not all-powerful: they have a production limit which is measured in litres per minute. The most common capacities are 5, 10 and 15 litres per minute , but there are models with much greater capacities. If you want to know how much you need, you must take into account the number of people living in the house and the number of consumption points (bathrooms, kitchens and appliances).

If you already have a gas outlet, or if you don't mind switching to butane or propane, a water heater is your best choice. It is very simple to install and its fuel costs less than electricity.

“The key in a gas heater is its production limit. Whether it can heat 5, 10, 15 or more litres per minute.”