Central Heating

[have ago]

I have a fault on my central heating system, the fault is that the hot water allways works but the heating side only works intermittantly the honeywell valve gets hot sometimes and I have noticed it seems to be working (motor running) with the heating switched off.
My problem is i do not know if it is the valve or the program unit.

[gasman]

Difficult to say without having a look myself, but you say the motorised valve seems to be working, but have you tried it in the manual position ? you should get both hot water & heating then. If not it is prob the valve. If it does work then it could possibly be the Acctuator on the valve head, the programmer or the wall stat at fault. If you havent got the correct testing equipment it could be an expensive job replacing everthing till you find out which part is at fault.
Anyway Good luck.

[jproximo]

you could have an air pocket, try draining the system, and when refilling open the bleed valve at the systems highest point to release any pockets of air, if this doesn.t work then start thinking it's gonna cost ya.

[dr john]

I've had the plumber in several times since switching the heating back on this year, had a new thermocouple installed and everything.

Finally he pointed out that there should always be one radiator in the system which is deliberately left without a thermostat. Otherwise when the weather temporarily warms up again they all switch off and the boiler overheats, triggering an automatic cutoff. Mine was switched off, and since I've switched it back on the heating has worked fine.

Check which one yours is, and make sure it's left switched on.