constant boiler firing

[cruiser]

Hi guys I've been ut to a boiler and it keeps firing up .when programmer is turned off .on heating and hot water.but there still power to both 2 x Port valves .and pump / boiler .there no frost stat . any ideas ?

 

[leesparkykent]

How did you check the power to both valves and on what colours? normally it would be a stuck micro switch in one of the valves. If you switch it off, disconnect the oranges, turn back on and check witch orange is live then this would be the one with the stuck micro switch if the programmer is turned to off on both hot water and heating. Depending on the make of two port you can replace the micro switch or just replace the head. Whilst the head is off check the valve is freely turning.

 

[cruiser]

checked power with volt stick .to both cables to valves both lit up and pump boiler is on with programmer off .do you think faulty programmer or you think it's a faulty valve.but if faulty valve then why power to both valves .when off ??

 

[SimonG]

Wasting time with a volt stick. Need to check voltages on valve head wires.

 

[ShaunCorbs]

checked power with volt stick .to both cables to valves both lit up and pump boiler is on with programmer off .do you think faulty programmer or you think it's a faulty valve.but if faulty valve then why power to both valves .when off ??

well the prog sends power to the room stat which opens the zone valves when heating call, so could be easy way to test

but get a multimeter

 

[Chalked]

Stuck micro switch.
Volt stick will be useless as there is always power to the grey. Check voltage on the brown first. If there is, then it's getting power from somewhere else. If no power on brown, but there is on the Orange. Then it's a micro switch.

 

[leesparkykent]

As above only real way to check is with a multimeter.

 

[Leo21]

You gas safe cruiser? We could do with knowing before we give out advise mate. We don't know who were telling what!

 

[Chalked]

You gas safe cruiser? We could do with knowing before we give out advise mate. We don't know who were telling what!

No need to touch the boiler to test motorised valves Leo.:grouphug:

 

[Billy Bob Bob]

volt sticks are only good for touching boiler cases etc before you work on them,fault finding can only be done with a multi meter