Boiler Problem

[Denn013]

The overheat cut out has started to operate on our Potterton Prima 40F gas boiler. It restarts and operates fine after resetting the cutout after allowing time for it to cool down. This happens a couple of times a day. Does this mean the boiler thermostat needs replacing? or could there be another likely cause?

Is it a job I can do myself? or de we need a professional? Any ideas of likely costs for repair and boiler service?

Any advice will be appreciated - any good boiler repair chaps in the Bolton/Wigan Area?

Cheers - now off the pub

[John Stumbles]

Could be lack of water to the system. Are the upstairs rads hot all the way up? (see

If you turn down the boiler thermostat does the overheat cutout still trip? Does the flow pipe get much too hot to touch? At Max on the boiler stat it should get to about 80C, that's as hot as the rad on your car, and hot enough that you can't hold it for more than about a second with dry hands. With the boiler stat lower it should be cooler: if it isn't then maybe the boiler stat's not working (when you turn it down the boiler should stop). If The cutout is going with modest flow temperatures than the overheat stat itself may be faulty.

[Denn013]

[John Stumbles]

And is the water very hot (about 80C if you can measure it, or too hot to hold by hand)? That would certainly indicate the thermostat. If it's a type where the thermostat sensor sits in a pocket in the heat exchanger make sure it hasn't just fallen out though!