Central Heating Stopped Working

[keefyg]

Hi,

I've had a good look around these forums and cant find the answer I need.

Last weekend when I turned the central heating on I noticed nothing happened, the boiler didnt fire up like it usually would, as if the on signal is not getting to it. The hot water is working fine though. Its a gas Thorn Housewarmer 30/45 back boiler, its serviced yearly but other than the programmer (see below) has had nothing altered on the system recently

As the hot water was working I thought it may be the programmer, I swapped the old one about 6 months ago for a digital one as the dail didn't spin round anymore, so i tried putting the old one back on but still got the same problem.

My next thought is to try the room thermostat which is an old honeywell analog thing.

Is there anyway I can test if this is the problem before getting a new one or could anyone suggest anything else it could be. I understand the pump and the motorised valve can both fail and cause this kind of problem but I would have thought the boiler would still fire with these problems?

Many thanks in advance

 

[gas4you]

If the motorised valve fails at the microswitch the boiler and pump will not get the live feed to make them work. Valve motor is operated by thermostat/programmer to open and shut valve, microswitch has permanent live to one side and other is switched by valve opening and then sending live to boiler etc

orange wire from valve is the live supply to boiler/pump. Check this

 

[Agile]

For the sake of £10-£20 why not replace the room stat?

Even if its not the problem it will be modernised and eliminated for the price of a boozy night in the pub.

Tony

 

[keefyg]

thanks for the replies, i'll get the motorised valve checked this weekend, and if its not that replace the thermostat. Cheers