Potterton 40e boiler won't switch off automatically

[onthepiste]

Hi,
I have a friend with a Potterton 40 e boiler on a gravity fed system. For some reason the boiler now stays on constantly and can only be turned off by setting the boiler thermostsat to zero. They have had someone in who suggested replacing the timer control panel but this has failed to cure the problem. Any ideas would be greatly appreciated.

 

[corgiman]

the boiler stat is gone I rekkin

the timer wont have nowt to do with it. out of interest why did you think it might?

 

[onthepiste]

the boiler stat is gone I rekkin

the timer wont have nowt to do with it. out of interest why did you think it might?

Thanks for the reply Corgiman.
If the boiler stat is gone would it still turn off the boiler when set to zero? A previous thread mentioned a faulty motorised valve micro-switch, any thoughts on this?
The timer was previously changed by a plumber who thought that it might cure the problem.

 

[corgiman]

yes cos setting the stat to 0 is effectivley turning the stat off manually

 

[Soggy_weetabix]

yes cos setting the stat to 0 is effectivley turning the stat off manually

Boiler stat is shot as CM said. Check M/vlvs aswell

Boiler stats do fails to shut boiler off on profiles on ZERO sometimes.

Change stat and than look at valves if problem persists.

CM knows his stuff!

Dave

 

[corgiman]

CM knows his stuff!

Dave

Now now Dave You know thats a lie