Baxi combi 80 eco problem

[nogoodatfaultfinding]

Went to this boiler today a bit blind.
Customer called stating that heating was fine however hot water was intermitent, show up with new diaphram as over the phone this appeared to be the fault.
Stupidly to busy talking forget to turn off cold supply and undo first top nut on housing.
Good quantity of water gets out over everything, quickly shut water of and carry on with change.
Fire up boiler after refill however now getting nothing.
Boiler powers up, pump kicks in, fan kicks in however no ignition.
Checked M2 Plug on pcb and have continuity across pump and over heat however have none at ports 1 and 2 for the CH thermistor.
Thermistor itself showing 9.5 Ohms is this correct?

Any ideas?
Hoping its not to do with my lack off attention with the water as it seems to go through the initial cycle, but now have no heating or water.
Both flow switches now making contact but just wont light.

Any help or advice would be gratefully received.

Thanks

Charles

 

[powell30]

Silly question but did you check it lit before you worked on it? Just had a few customers say.....'well it was working before!'

 

[nogoodatfaultfinding]

Silly question but did you check it lit before you worked on it? Just had a few customers say.....'well it was working before!'

Yeah mate defianately lit previous to this.

Its one of them though where they have not had it serviced since 2002 and in the last 6 months have had a new fan, new expansion vessel, new summer winter switch and now this.
Told them to get a new boiler but they are willing to throw good money at it.
I just cant get my stupid mistake with not turning off the cold feed out my head that it must be something i have done.

 

[powell30]

Ouch....sounds like pcb got wet but baxpoti ans poxi have more experience than i......maybe they can offer some advice

 

[nogoodatfaultfinding]

Ouch....sounds like pcb got wet but baxpoti ans poxi have more experience than i......maybe they can offer some advice

I agree but surely the PCB would short on the fuse if wet and not go through its cycle?

Wishfull thinking i suppose

 

[powell30]

Hmmm, i must be the unluckiest bloke then cause every time i get to change a hydrualic block i bloody soak the pcb......some work, some don't and some seem to......until ignition. Is the gas valve opening?

 

[sourcebranch]

Agree with above post. Is the gas valve working? are you getting voltage to gas valve? if you have you manometer on inlet nipple , do you see a drop when the gas valve should be opening? Have they got gas?
Have you accidentally pulled out ignition lead from board/spark generator?
Has boiler been vented? Reset?

 

[nogoodatfaultfinding]

Go on guess what it was then!!
Involved a shoe cupboard, some shoes and an emergency control only 3/4 open (hence the heating working).

 

[sourcebranch]

This would have shown if as I said by putting the manometer in the inlet pressure nipple. As the gas valve opens you would have seen the gauge drop to nothing. Lets not dwell on the past, the main thing is you have sorted it

 

[nogoodatfaultfinding]

i know but with CH firing i just didnt think!!!