Immersion heater newbie error

emilygilmore

How much would it cost if you left your immersion heater on for two months without realising? No reason... but am I going to need to take out a second mortgage?

comeandgo

We had to use ours for a few days and calculated it as £3 per day but we had to heat a large tank from cold then left it on all the time.

Owain_Moneysaver

Depends how much heating it actually has to do, it would be about £150 a month running continuously -- which it won't have been.

[Deleted User]

Hi,

and it depends how well insulated tank is, how much water being run off.

emilygilmore

Ah thanks for your replies, we had an average of 1.5 showers a day and the tank is quite modern so hopefully it was not doing too much reheating work. The plumber was really horrified now to work out why the heating seems to come on with the hot water timer..

Cardew

To set your mind at rest, a modern well insulated Hot Water tank will lose between 1.5kWh and 3.0kWh every 24 hours with the water set to 65C - you can sometimes see the British Standard figure stamped on the casing.


Taking a worst case scenario of 3.0kWh a day your losses will be approx. 180kWh in two months - say £22.


You can then deduct from that £22 the losses that would have occurred with gas CH - say £7.


The additional cost of used water heated by electricity instead of gas might add a further £10 to your losses.

emilygilmore

Oh wow seriously? I have been so worried about this after what the plumber said! Was going to cancel Christmas!