Ever since we put the heating back on timed for the up coming colder months (About 7 weekes ago), the external boiler water pump is constantly running. The boiler has been used all year on timed for Hot Water, so has not been inactive.
I have also noticed that the boiler will ignite for 30 seconds or so even though the timer control says it should not come on.
EG came on at 10:14pm tonight even though timer says
Time 1 - 05:30am to 07:30am
Time 2 - 05:00pm to 08:00pm

Have tested room thermostat (Downstairs hall) by changing temp and boiler does not react.
Have notied that the thermostat control box attached to the boiler has a number of red LEDs inside it which are constanly on, not sure if this is correct or not, as never looked before the fault occured. Any suggestions would be much appreciated.
Regards Matt

Matt D, November 2008

if you turn your room stat from high to low and your hear it click then it should be working ok

your time clock overrides your room stat so the fault is more likely to be there

as for your pump running after it should have gone off,,, some times a pump over run was fitted that let the pump run for about 10 mins after the timer turns it off ,,,but that ws fitted mainly on low content aliminium heat exchanger boilers and yours is a cast iron heat exchanger

your clock is most likly to be the culprit because the boiler cannot work unless the clock tells it to ,,,also check your clock is mounted properly on the back plate on the wall just in case you knocked it

room stats a very cheap so it may be worth changing at the same time just in case,, there are3 or 4 wires inside so you need the correct stat with the same kind as yours 3 or 4 wires inside you should also use a qualified electrician

gasman, November 2008

Found answer on diynot.com forum. found out it was 1 of the motorised valves that was sticking on. Now fixed.

MattD, November 2008