Immersion heater

[chazza]

Approximately how much would it cost to run an immersion heater for an hour?

[Ethel]

https://www.energyefficiency.powergen.co.uk/advicecentre/category4/WiseAppliances.htm


About 20p an hour on daytime electricity.

[brachiopod]

Typical immersion heaters are around 2 - 3 KW (Kilo-Watts)

A unit of electricity is the KWh (KiloWatt hour), which is the amount of energy used by a 1KW appliance in one hour.

So your immersion will use 2-3 units per hour. Depending on the cost of a 'unit' from your supplier, (typically around 10p per KWh inc. VAT), then you are looking at 20 - 30p per hour max.

Remember though, once your immersion reaches the temperature of the thermostat setting, it will switch off. So, if starting from cold, once it reaches the correct temperature

[brachiopod]

(whoops - premature submission !)

... it will switch itself on and off intermittently as the water in the cylinder cools or hot water is drawn off and replaced by cold.

So Ethel's answer of about 20p an hour is probaly about right.