'Sticking' thermostat problem with a Quantum Q80 Gas boiler.

ircoha

The problem is the following:

Thermostat has 5 settings 0 to 4 and is a dial.

In the last while, if the stat is set higher than 3 the boiler 'locks' once it reaches that temp

to restart I need to
1 move the stat down to about 2 or 2.5
2 cut the power to the boiler
3 restore the power and the boiler starts again.

The boiler is no longer serviced in Ireland but I can order parts from UK.

Any input appreciated, as I dont understand what 'repowering' the boiler does.

Also concerned that it will not restart some evening when herself is having a dinner party. Not a cheerful prospect:)

dave1980

hi, im a plumber and ive had experience with this problem, its that the working stat is on its last legs. even though the stat is set at three it is not reading properly and the boiler is actually goin to its maximum temp. when this happens it is very easy for a boiler to overheat and lockout on the high limit stat and that is why you have to manualy reset the boiler. you will need to order a new working stat i hope this is of some help

ircoha

Thanks, you answer explains why the system is hotter than normal at the lower settings.