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What is an immersion heater and how does it work?

What is an immersion heater and how does it 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.

Do immersion heaters use a lot of electricity?

Cons of immersion heaters. Heating water using electricity is more expensive than heating water with gas. A typical immersion heater uses three kilowatts of electricity an hour, so it will cost the average house about 50p an hour to run.

Is immersion water heater safe?

Is it safe to use an immersion heater? Yes, it is, provided you buy a good product and use it appropriately. You can even use it to boil drinking water and coffee. Electrocution, burns, and short circuits may occur if you do not use the correct immersion water heater or wrongly utilize it.

When should you use an immersion heater?

We would typically recommend switching the immersion heater on around two hours before you intend to use the hot water to give it time to heat the cylinder. Many of these systems will use ‘Economy 7’ electricity tariffs and, as such, will have an on-peak and off-peak immersion heater.

How Long Does immersion take to heat water for shower?

It can take between one to two hours for an immersion heater to heat a tank of water to the desired temperature. The time varies depending on how powerful the heater is, as well as how much water the tank holds.

What happens if immersion is left on?

“The main problem with leaving an immersion on constantly is that the immersion thermostat will be constantly switching on and off. After so many hours the thermostat will give up, causing one of two problems.” “Problem one is that the immersion will not work. At all.

How long does it take for an immersion to heat up water?

The immersion heater is connected to the mains electric via a cable and has its own on/off switch. When the heater is turned on, electricity heats the metal element and this heat passes to the surrounding water. It can take 1-2 hours for the water in the cylinder to reach your desired temperature.

Do houses still have immersion heaters?

It seems immersion heaters still have a place in the modern home as both a backup for your combi boiler and as a potential source of free hot water with solar technology. You can keep its energy supply switched off when it’s not needed so you won’t be wasting energy by having it.

What happens if immersion is left on without water?

Just like geysers, using the immersion water heater with inadequate or no water in the container or the bucket will burn and damage the coil and make the appliance useless.

Can I leave immersion heater on overnight?

Hi Katie, Immersion heaters have a thermostat which turns them off when they reach the target temperature. Leaving it on for a few hours is enough for it to warm up and so it will be no different to leaving it on overnight.

What are immersion heaters and how do they work?


  • Storage/Tank Heating
  • Freeze Protection
  • Sterilization
  • How much does it cost to replace an immersion heater?

    They may determine that you can simply replace a part of the immersion heater (such as the heating element) rather than having to replace it entirely. The cost of replacing an immersion heater varies depending on its size and type. If there are no complications, it will typically cost around €140 excluding VAT.

    What principle is used to make an immersion heater work?

    Principle of Operation. Immersion heaters are made by encasing a nichrome resistance heating wire in a ceramic jacket which is then surrounded by an Inconel sheath.

  • Conduction and Convection. Once the Inconel sheath starts to heat,the water surrounding it starts to heat quickly.
  • Instant Hot Water.
  • Industrial.
  • Self Regulation.
  • How much electricity does my immersion heater use?

    Volume of tank x 4 x temperature rise / 3412 = Power (kW) required. For example, if the cold water in your 120 litre tank is 15°C and you would like it heated to 60°C, the calculation would be: 120 x 4 x 45 / 3412 = 6.3kW. So you would need at least a 6 kW immersion heater to heat a full tank of water in 1 hour.

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