DIY Doctor UK DIY Forums

I own a flat that has a very old electric underfloor heating system - it is like a huge storage heater in that it heats the floor up overnight and then slowly releases the heat during the day. The only controls are some room thermostats which, I guess, control the amount of heat stored.

The system is hooked up to an Economy 10 meter that feeds electricity to the system at 00:00-05:00, 13:00-16:00 and 20:00-22:00.

My tenant is complaining that it is not working properly and that the floor is nice and warm at 4 in the morning, but, stone cold by 9 or 10 o'clock. Likewise, by 8 in the evening there is no heat.

I know that these systems are notoriously user-hostile, but, it seems that the times of the electricity are not ideal.

So, I wondered if there is any way to alter the wiring such that we could power the system using "normal tariff" electricity for some of the current down times and, hence, fill in some of the gaps. I realise this would be expensive, but, may make it more comfortable.

This would require some sort of timer and some sort of switch that flipped between the 2 electric sources (peak and off-peak).

Has anybody ever tried this or know if is feasible?

Thanks

Yes it can be done, you can get units designed for immersion heaters with a boost feature which would allow you to push a button to get the extra heat.

As to if worth doing is another question, I have under floor heating in my mothers wet room, it takes two hours to warm up, so by time one presses the boost and gets the extra heat, the off peak will have kicked in again.

The problem with electric under floor heating is you have two thermostats built into one, one measures the floor temperature, the other air temperature. The floor takes both ages to heat and cool, so if the thermostat measuring floor temperature switches off, it could be some hours before it comes on again.

So I would be looking at some other form of heating to fill the gap when required, a small panel heater for example.