Central Heating

[vesuvius123]

some of my radiators are getting warm when only the water is on, could this be an electrical fault with the control box or is it a plumbing fault, just wondered if any one has had a similar problem, the heating side of the control was turned to off at the time.

[BRIGHT SPARK]

It sounds like a problem with Y plan valve.Try switching between domestic hot water and heating water a few times and see what happens.

[woofgang]

it might be the mixer valve, if you have one, or it might just be the water circulating round the system. How warn do they get?

[tballrossi]

out of 7 radiators 3 of them get warm, not hot though.

[The Builder]

Diverter valves (Y plan) can get stuck one way or the other.... or, in the middle somewhere. Enough to give hot water and allow water through for heating as well.

Often happens after the summer when the heating has been off for a while.
Tap it with a small hammer if it's accessible in the airing cupboard. Not so easy if it's contained within a combi boiler though.

[geno500]

Yes it would seem your valve that allows hot water from your boiler to run through you hot water tank to heat it is allowing some hot water to feed into your central heating ,if you look where the valve is it is normally in the cupboard where the hotwater tank is you will see a silver box with pipe work coming out if it,it has little levers sticking out the side,you could try moving them back and forth,also gently tap the box this can sometimes cure the problem

[Paulb14]

Depends what type of heating system you have, I had a gas fire with a back boiler, your problem happend to me and it was the none return valve that had broke so it was a plumber I needed not an electrician.