What is an immersion heater?

02nd July 2022

Today homeowners have several different options when it comes to generating hot water for their property. Some opt for a combi boiler, others go for renewables and a small number of people choose an immersion heater.

Whereas boilers create hot water using gas and solar panels create energy using sunlight, immersion heaters use electric. Here we’ll explain how this type of electric water heater works and what type of properties they’re suitable for. We’ll also weigh up the various pros and cons of having an immersion heater to help you decide whether it’s a sensible choice for your home.

How does an immersion heater work?

An immersion heater is an electric water heater that is found inside a hot water cylinder. It works a little bit like a kettle, in that it uses an electric resistance heater (that looks like a big metal loop) to heat the water around it.

Immersion heaters are connected to the electric mains via a cable. This means you can switch them on and off as you please. The water in the direct hot water cylinder doesn’t need to be constantly hot.

Today some people choose to connect their immersion heaters to renewable energy sources, like solar panels. This is considered a more eco-friendly way to create energy and will save you money too.

Who uses an immersion heater?

The majority of people have a boiler to heat their hot water. This might be a traditional boiler, with a hot water tank or a combi boiler, which will heat both your radiators and water supply. Some people may choose to install immersion heaters as a backup water heater, especially if their boiler is older and not as reliable.

Immersion heaters can also be used as a main hot water source. However, this only tends to be in properties that aren’t connected to the main gas supply.

Advantages of having an electric water heater

The main advantage of having an immersion heater is that it’s separate from your boiler. This means if your boiler breaks down you can still generate hot water for your home.

Another advantage of immersion heaters is that if the hot water cylinder is well insulated, your water will remain hot for several hours, even after the immersion heater has switched off. We recommend installing an immersion heater timer, which works just like a thermostat. This means that when the water reaches the desired temperature, the immersion tank will automatically turn off, so you aren’t wasting money.

You can also keep costs low by asking your energy supplier to put you on a time-of-use tariff. Set your immersion heater timer to switch your hot water heater on during off-peak hours so you can save money.

02nd July 2022

Disadvantages of having an immersion heater

Although there are ways you can keep your immersion heater’s running costs down, heating water with electricity still tends to be more expensive than using gas. According to the review website ‘Which?’ a typical immersion heater will use three kilowatts of electricity an hour, which will cost the average household 50p per hour. You’re likely to need your immersion heater on for at least a couple of hours a to generate enough hot water, so the cost soon mounts up.

Alternatives to immersion heater tank for hot water

As we’ve discovered from looking at the pros and cons of electric water heaters, the main issue is the cost. No matter which way you look at it, it’ll always be cheaper to heat water with gas than electricity.

Installing a boiler for hot water

If you have access to a gas pipe, it’s more cost-efficient to run a boiler than use an immersion heater daily. The type of boiler you need will depend on your property, how many radiators are installed and how much hot water you require.

If you’ve got an older boiler, with a separate hot water cylinder that isn’t very efficient, you’d still be better upgrading to a more efficient combi boiler than using an electric water heater. A combi boiler will provide hot water, as well as heating and will save you money in the long run. It will also take up less space than a traditional regular boiler and you can always install an immersion heater as a backup.

Here at Hometree, we sell a range of different boiler models from market leaders, Worcester Bosch and Vaillant. These two brands offer some of the very best boilers available, with something to suit properties of all sizes. Our installations include a free smart thermostat and a 5-year warranty as standard.

Renewables for free hot water

Renewables are also worth your consideration, especially if your property doesn’t have access to gas. We’d recommend looking into schemes such as the Renewable Heating Incentive from the Government, which offers financial incentives to make your new installation cheaper.

Did you know you could also have a device fitted that will redirect any energy you’re not using to your immersion heater? It’s the best way to generate hot water free of charge!