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

On Sat, 31 Mar 2007 14:21:42 +0000, Denn013 wrote:

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?

Could be lack of water to the system. Are the upstairs rads hot all the
way up? (see
http://wiki.diyfaq.org.uk/index.php?...Heating_Repair)

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.

Yes, still trips when stat is turned down. All rads operating fine. I'm
pretty sure the boiler stat itself is duff. I'd expect the boiler would
swith off if the stat is turned right down when the boiler is running but it
only goes off when it actually hits the off position.
Cheers
"John Stumbles" wrote in message
news
On Sat, 31 Mar 2007 14:21:42 +0000, Denn013 wrote:

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?

Could be lack of water to the system. Are the upstairs rads hot all the
way up? (see
http://wiki.diyfaq.org.uk/index.php?...Heating_Repair)

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.

On Sun, 01 Apr 2007 11:29:36 +0000, Denn013 wrote:

Yes, still trips when stat is turned down. All rads operating fine.
I'm pretty sure the boiler stat itself is duff. I'd expect the boiler
would swith off if the stat is turned right down when the boiler is
running but it only goes off when it actually hits the off position.

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!