Thanks for the pointer Spacethegas, I'll have a look in the morning, let you know.
Vaillant Combi Compact heating won't shut off!
- Thread starter nickthesafe
- Start date
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this boiler was the "bugatti veyron" of its time.
there will be nothing else like it, & there wasn't at the time.
apart from the leaking h/e ramifications, the fact it has 4 pcbs & the calorifier (which was updated). i think they were great.
there will be nothing else like it, & there wasn't at the time.
apart from the leaking h/e ramifications, the fact it has 4 pcbs & the calorifier (which was updated). i think they were great.
OK, pressure diff valve seems to operate OK, pin moves out with a great deal of force. I pushed in the GV pin manually, still no light up. Reassembled.
If i can add another symptom which might help point to a problem; The pop out cut off switch on the main panel next to switches will not push in and hold in, the cut off light is not illuminated and neither of the green/amber leds are illuminated. Main switch neon is on.
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this seems an odd problem as it appears unrelated to your original fault.
in c/h mode.
fan runs.
pump runs.
diverter closes both microswitches.
boiler does not attempt ignition (no glowing yellow neon).
next thing to check is air pressure switch. this is located at the top rear of boiler.
there are two connecting clear rubber tubes. this sense that the fan is running.
remove a tube & blow or suck to operate the switch within.
do this just after the fan starts.
does anything happen ?
be careful the electrical contacts are sometimes exposed.
in c/h mode.
fan runs.
pump runs.
diverter closes both microswitches.
boiler does not attempt ignition (no glowing yellow neon).
next thing to check is air pressure switch. this is located at the top rear of boiler.
there are two connecting clear rubber tubes. this sense that the fan is running.
remove a tube & blow or suck to operate the switch within.
do this just after the fan starts.
does anything happen ?
be careful the electrical contacts are sometimes exposed.
OK Spacey, tried that - still nothing. And yes this is now a different problem, the original one was a sticky DHW cam, fixed that only to find now the boiler won't fire.
are you sure the ap switch is receiving power? can you hear it click when the fan starts?
next disconnect the inline connector in the NTC lead. if it lights the dhw stat will probably need changing. its normally open circuit between its terminals when cold.
next disconnect the inline connector in the NTC lead. if it lights the dhw stat will probably need changing. its normally open circuit between its terminals when cold.
Yeah definate click after fan starts up. disconnected inline connector NTC lead. still nout!.... I really appreciate your assistance spacethegas.
HI Tony, well i pulled the hose and blew into it towards the gas valve with no effect. so i presume it's working
edit to add.... the lockout button will not engage at all if this means anything?
edit to add.... the lockout button will not engage at all if this means anything?
A busted air pump won't make any difference to the ignition Tony. The boiler will light on minimum burner pressure (set on the GV) and the pump just operates the valve from max to min (when the right light comes on).
The problem is why the lights don't come on. The left hand should come on with a demand followed a second or so later by the right hand one and the air pump operating.
To the OP are you definately sure the microswitches on the diverter are being closed/open as the diverter shunts left/right depending on demand.
What fidling on the boiler did you do? Have youi checked all wiring connections. What about the little thermostat at the back lower left?
No the lockout button only clicks back in if there has been a lockout and the red light is on.
How about the three fuses....fuse carriers on metal box front panel.
The problem is why the lights don't come on. The left hand should come on with a demand followed a second or so later by the right hand one and the air pump operating.
To the OP are you definately sure the microswitches on the diverter are being closed/open as the diverter shunts left/right depending on demand.
What fidling on the boiler did you do? Have youi checked all wiring connections. What about the little thermostat at the back lower left?
No the lockout button only clicks back in if there has been a lockout and the red light is on.
How about the three fuses....fuse carriers on metal box front panel.
HI Gasguru,
Yep microswitches switch in and out depending on demand, as for fiddling; well before the cam switch was resolved i have to admit to pulling the control unit disconnecting all the connectors then refixing - Initially i forgot to plug on the one which is just a link (at the rear of the lowest of the three boards), then put that in place. I have checked the connectors over and over again though... should link w18 on the middle board be cut? it is in any case. fuses AOK.
Yep microswitches switch in and out depending on demand, as for fiddling; well before the cam switch was resolved i have to admit to pulling the control unit disconnecting all the connectors then refixing - Initially i forgot to plug on the one which is just a link (at the rear of the lowest of the three boards), then put that in place. I have checked the connectors over and over again though... should link w18 on the middle board be cut? it is in any case. fuses AOK.
Yes if you have the stainless sardine can type secondary heat exchanger and it's a hybrid temperature control board ...normally HY stamped on the control box.
How about re-checking the boards...perhaps you've bent a board connector pin. Have a good look at the solder joints while you're at it.
Make sure both the silicon tubes are connected to the back of the box otherwise you'll have another problem with the air pump. Normally need to remove the side casing to get them back on.
I've pulled the control unit, extracted all PCB's, checked solder joints refixed, reconnected leads checked connections (and air pipes) ..... still no ignition.
I think I've done all I can without venturing into areas that I shouldn't go!. I'll leave it to BG now and let y'all know how it turns out. Thanks for your guidance (and patience) Spacey, Guru, Agile & Namsag
I think I've done all I can without venturing into areas that I shouldn't go!. I'll leave it to BG now and let y'all know how it turns out. Thanks for your guidance (and patience) Spacey, Guru, Agile & Namsag
i didn't realise the op had messed about with the boards.
Agile.
why butt in on a thread you cannot contribute anything useful to due to your lack of knowledge in regard to the operation of this appliance.
Agile.
why butt in on a thread you cannot contribute anything useful to due to your lack of knowledge in regard to the operation of this appliance.
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