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N

nowucit

hi guys hope your well

went to look at the above which will not fire up main burner for either CH or HW. Not got lots of experience with these but from what I can see controls are calling for heat/hot water, pilots lit, gas valve clicking shut when thermocouple cools so best I can narrow it down to is the thermostat.

anyone got any idea of what else to check before I replace or can point me in the right direction if I've wondered off :confused5:

any advice greatly received :wink5:
 
If controls are ok check theres 240v at the pump , if pumps running check motorised valve if 3port, id go for the pump, is the system fully pumped ?
 
These are very basic controls nowucit ... You have a switched live from external controls that go through the boiler thermostat switch to operate the gas valve. Is there power to the boiler thermostat? If so then is there power to the gas valve? Once you know this you'll have an idea where the fault lies 🙂
 
Yeah power to both

If you have 240Vac L>E & L>N, 0Vac N>E then check resistance of gas valve. By the way, gas valve control has been turned to main flame?

Most likely suspect is ......... The tests above will tell you 🙂
 
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Haha ... OK many thanks diamondgas I'll double check everything

🙂 I could say it's this or that nowucit, but unless I'm there testing I can't be sure. A neutral fault will spark up a glow on a neon screwdriver but only testing will confirm where the fault lies 🙂

Let us know what you find out 🙂
 
I've left the gas valve control on pilot only, after servicing and then end up swearing at it for not going to main flame, then realise I've not turned the knob to main burner!

Good advice there from diamondgas though, that should get you to the bottom of the problem!
 
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Thanks fellas, knob definately turned to main burner, given what I checked yesterday and diamondgas advice I'm thinking more along the lines of gas valve but will go back and check everything ... Had not initially considered the thermostat switch but power is definately getting through to the gas valve.

Probsbly over thinking king it and need to go back to basics
 
If power is getting to the gas valve, then the thermostat should be ok.

Have you connected your manometer to the burner pressure test nipple to see if any gas is going through? You could also check to make sure the injector isn't blocked.
 
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