Can't get a straight answer Immersion heater

Owain_Moneysaver

Richie-from-the-Boro wrote: »

How much it looses is a function of insulation. Example a PartL cylinder will lose 1/2 as much as a non PartL cylinder, ditto the pipe run ≥ insulation.

And of course that heat loss isn't wasted: it contributes slightly to heating the house.

Richie-from-the-Boro

All electric immersion heaters cost [most] everyone on these islands the exact same amount - 3 kWh @ their individual tariff rate.

This because most are the same 3kW elements, the differences are most heat to 50°C+ because of legionella others have a lower setting - some are 120 litres others larger or smaller volume - some lose more through poor insulation others with good insulation lose less.

E7 [and other non-core rate] users have the best default advantage of twice the insulation value and 30% cheaper individual tariff rates.

Richie-from-the-Boro

Owain_Moneysaver wrote: »

And of course that heat loss isn't wasted: it contributes slightly to heating the house.

- it certainly does, zero actual waste, just converted to usable heat value !

footyguy

tomsolomon111 wrote: »

I have read dozens of sites and still can't get a straight answer on this. How much does it cost to run an immersion heater full time?

Let's say for one minute money is no object, I have heard it costs 50p per hour to run one of these with a 125l tank and a 3kwh heater element. Others say it switches on every 12 minutes for 6 minutes which would mean it was on for at least twelve hours a day. With both of these scenarios the usage would be, with one bath a day, approximately for the 50p hr £84 per week and for the on 12 out of 24 at my current tariff of 13.37p ( taking into account it supposedly takes 1h to reheat the water after a bath) 13h x 3kwh x 7d = £36.50pw

I know I'm not using £36pw and definitely using less than £84pw.

Everybody has advice on how to use these things, but never have I found any actual figures on how they work and how much they are using. Is there some conspiracy to stop people know the real fact about these things, or do people really not know. If you reply to this post with why don't you just turn it off when not using it. I will ignore you! :rotfl:

So you know it's a 3 kW heater, now you need to multiply that by the kWh charge applied by your electricity supplier.

That's in the most simplistic form, and would be the cost of the heater runing constantly.
In reality, it will be thermostatically controlled by a thermostat. So how long it actually runs will depend on various variables such as (a) temperature thermostat is set to, (b) level of insulation, (c) ambient temperature (d) hot water consumed (e) temperature of incoming water etc.