potterton promax 15he

[cdodds2004]

After some advice on a promax 15 he

the older style one with 2x pcbs

Boiler has delayed ignition intermittantly

boiler has had over the last few months

electrodes and leads
ignition pcb
gas valve

Have checked burner its all good and is the ceramic one and not gauze

Boiler will light fine with case off as soon as you put the case on it starts playing up,
lights ok
then delayed ignition but lights
or even no ignition at all

tried a new fan today as it has to be something to do with air flow and made no diffrence what so ever, also tried a primary pcb. nothing

its a vertical flue but is straight through a bungalow roof and only has the 1 x flue section.
im very confused now.

Anybody have any ideas what else i can look at?

we inherited the job from another firm who had also been struggling.

regards Chris

 

[ShaunCorbs]

Aps??

 

[cdodds2004]

Doesn't have one mate

 

[ShaunCorbs]

That's the one that has the same internals as the old solo isn't it ?

 

[kozak1968]

You sure its not a lazy fan, not running full speed?

 

[ShaunCorbs]

You sure its not a lazy fan, not running full speed?

hes changed the fan

(edited spelling doh)

 

[kozak1968]

hes changed then fan

Is it brand new, taken out of an old boiler or been stuck in the van a while?

 

[ShaunCorbs]

Is it brand new, taken out of an old boiler or been stuck in the van a while?

dont know

 

[mejmag]

Could be the rear part of the sump is caked with crud, restricting air flow out the flue. Worked on plenty of Baxi soloHE's which are pretty much the same boiler but slightly newer. They almost always have a build up on the rear section of the sump. You'll have to remove the fan and trap and drop the sump out (make sure you have a replacement sump seal kit as the old one will be shot to pieces when you remove it). You'll probably find a load of baked hard crud in the rear section. Clean that out and put back together. This is supposed to be done on every service according to MI's but rarely is because the sump seal never goes back right and people don't carry them as spares. Worth a try if nothing else is working. Let us know.

 

[Moffski72]

Combustion chamber seals is my shout for that, had a couple do similar things and that sorted it for me. Good luck...

 

[mejmag]

Forgot to mention, check the burner. Take it out, hold it up to a light, look through the bottom of the burner and tilt it from side to side. You should see many little pin holes of light shining through. If the majority of the little pin holes don't have light shining through then they are blocked and you'll be able to see it. Tab the burner and run a hoover round the inside. This has happened to me many times and causes ignition problems as the gas sometimes gets through and sometimes not. Let us know how you get on mate.