Central Heating switches on when the hot water is heated All aspects of plumbing questions and answers, help, tips and information

[Tatt]

Our central heating warms up when the boiler is on for the hot water - this occurs even when the central heating timer is switched off.

I've looked at the controller unit (next to the tank in the airing cupboard) when the hot water is being heated, and both the light for the central heating and the hot water lights glow.

Is it possible that the system was wired incorrectly?

The house is 4 years old.

[bjbiker]

It sounds like you motorised valve is defective and letting by.
Regards Bjbiker

[Paulo83]

Its not 'honeywell' controls is it??

[Tatt]

Hi

Thanks for the replys. I have "Potterton Controls".

Tatt

[Kenj]

Hi Guys,
Sorry to dissagree, but if the CH light is lit on the Control Unit / Programmer, then the relavent motorised valve will be turned on (Opened), if the room stat (if fitted) is also on.
This light is not a feedback signal saying that the motorised valve is open. It is informing you that the Central Heating is selected (ie on, or enabled). This light should never come on when CH is not selected on the Control Unit.
And in answer to the original question:- Yes I suspect that the unit is miswired.