Baxi boiler problems

[underwurlde]

Of course, it being Chirstmas the boiler's causing problems...

The boiler is a Baxi Solo 3 pfl-50.

1) Initial problem was no heat. This was down to the venting fan not working and hence the air pressure switch not operating. I replaced the fan with an ebay one for £30 and fitted it myself instead of shelling out for a 'proper' one for £168 , not including fitting.

2) now, something wierd is going on: *sometimes* the boiler, during heat demand, when cycling will vent gas!!!! All the lights on the boiler are on. The problem is that the pilot light, when it goes on, does not ignite... after a delay the main gas valve opens and chucks a load of gas out of the vent!!!

How this is possible on a safety critical piece of equipment is beyond me.

3) So I replace the PCB (with a new one), again with one from ebay for £50 instead of shelling out £150. ... now what happens is that this (what appears to be more modern design of PCB) will get 'stuck' and will not respond to heat demand.... and hence my house is freezing cold.

ARRRGGH!

Any pointers will be greatly appreciate.

Thanks in advance,

Andy

PS I have gone to the lengths of reverse engineering both of these PCBs and have circuit diagrams of both 'old' and 'new' control PCB boards.

 

[HarrogateGas]

Yes, stop using cheap ebay parts, get genuine parts and get them fitted by someone who knows what they are doing. Deep pockets and short arms springs to mind............


Ho Ho Ho.

 

[underwurlde]

They were genuine parts btw. Yes I fitted them myslef after having been told how to do it and that it was 'easy to do' by my heating engineer friend.... and yes it was dead simple to replace the fan and the PCB was just a matter of unplugging some connectors and reconnecting.

OK, I'll admit it: Perhaps I am being a stinge! ... but I've just had to fork out over £2,000 to fix the wife's car, it's Xmas and my pockets, regardless of depth, are empty!!!!

2009 has NOT been a good year.... my car also blew it's head gasket and is now scrap. .... roll on 2010!

Andy

 

[BingoBongo]

They were genuine parts btw. Yes I fitted them myslef after having been told how to do it and that it was 'easy to do' by my heating engineer friend.... and yes it was dead simple to replace the fan and the PCB was just a matter of unplugging some connectors and reconnecting.

OK, I'll admit it: Perhaps I am being a stinge! ... but I've just had to fork out over £2,000 to fix the wife's car, it's Xmas and my pockets, regardless of depth, are empty!!!!

2009 has NOT been a good year.... my car also blew it's head gasket and is now scrap. .... roll on 2010!

Andy

skint is better than dead,get your mate to sort it for you or at least give you a proper diagnosis,in the mean time turn it off and dont touch it

 

[underwurlde]

^ Good advice, thank you. Yes it is all off and has been since the venting gas issue.

Unfortunately my heating engineer friend lives miles away.. I've promised the wife (and now you guys) to contact local heating engineers today.

I PROMISE!!!

Andy

 

[underwurlde]

OK, heating engineer been and gone (great guys at town-gas.co.uk)...

He was completely happy with:
a) My new controller PCB from eBay.
b) The new fan from eBay and the way I had fitted it.

.......

So, to the problem...

The 'old' PCB does indeed have a known design fault which the newer PCBs have overcome, so in went my new PCB from eBay.

The problem is down to the sparking electrode WHICH ALSO ACTS AS A FLAME DETECT (it picks up the negative ions from the pilot flame).... you learn something new everyday!

Anyway the electrode was slightly bent out of shape making it work intermittently: hence a bit of bending of this electrode back into shape has completely solved the problem. (It is apparently not unheard of for these electrodes to get bent out of shape over time due to the high temperature environment).

Cheers,

Andy