Economy 7 heating

Cardew

ginnyknit wrote: »

I have had economy 7 for many years and don't particularly love it. However I had a disabled shower fitted for hubby recently so decided to turn off the hot water and just heat it up for an hour or so every couple of days, i am amazed the water is as hot as if I had it on for the full cycle - how much extra has that cost me over the years???

I assume you mean "heat it up for an hour or so" during the 7 hours of economy 7?

Actually you probably have lost very little over the years.

A well lagged hot water tank with a full tank of hot water at 65C will lose about 2kWh to 3kWh in 24 hours.(they are tested to a BSI spec)

You still have hot water in your tank using your method, so although you will lose less heat, the difference is probably about 1kWh a day - say 5p.

However, and this is very important, that heat is not 'lost' as it warms the fabric of the house. You have in effect another small 'storage heater' albeit with a very low output.

Admittedly in the summer you don't need that leaked heat from the HW tank, but the rest of the year you will.