Radiators on when heating is off!

[ktmchris]

Hi all, newbie poster here!!

I have a problem with my heating system (several actually but I'll save the others for another post!) in that sometimes one or more radiators are on permanently despite the controller being set for hot water only and it being off (i.e. outside of the time hot water is set to come on for)

System details as follows:
I believe it's a sealed pressurised system
GlowWorm Fuelsaver Complheat boiler
Pressure/expansion vessel in loft - no cold water tanks
Hot water tank
Two valves in airing cupboard adjacent to HW tank; a Danfoss HPA2 actuator and a Honeywell V4043H1056

From trawling this superb site I reckon the problem must be with one of the valves, but how do I tell which one? I disconnected the orange wire from the actuator valve at the connection box and heard the system shut down, so have come to the conclusion that it's the actuator head thats at fault - is that a safe assumption?? Was the orange wire the right one to disconnect? By the way, disconnecting the orange wire from the Honeywell valve didn't seem to make any difference.

I'm working on the assumption of course that the orange wire was the right one to disconnect, and I'm hoping that it was originally wired up correctly!!

Any help or advice gratefully received

 

[twgas]

Sounds like the orange you disconnected is the correct one, as you call it the actuator I think it will be the dafoss valve that is the problem - seized in the on position - remove the head and the actuator will return to rest position and the boiler will shut off. If that happens you'll need a new valve, if not let us know.