Baxi 105e High CO

[Subby]

Hi all. Today I have done my first boiler service on my own and have come into a bit of a problem.
The boiler is a baxi 105e ; the working pressure and burner pressure andgas rate were spot on, and the o2 at the intake, but when I tested the extract, the FGA warned of high CO, the level kept rising beyond 600 so I took the analyser probe out. The burner needed cleaning and there were a lot of dead insects around burner and on heat exchanger. The outlet sealing collar (between fan and flue) was snapped so I told customer that the boiler is dangerous and has to be left off until I replace the faulty part tomorrow. Could either of these problems have caused the high CO reading?

Also when I put the boiler all back together I had a small weep between the pump and pipe to the hex. I tried to fix it but ended up getting water everywhere.
I put the boiler back together and tried to fire it up out of curiosity, but fan didnt run and it would not light and the red Flame Failure light came on solid.
What was the possible cause of the high CO (dirty burner/damaged collar?)
Is the cause of the lockout me getting water splashed about, or is it because I took it all apart and something is not making contact etc??

Thanks in advance, just my luck my first job turned out to be a bit of a nightmare. I isolated gas and told customer the boiler is out of order until I return.

 

[newcastle phill]

If its the collar im thinking of, it could suck dirty exhaust air back into the intake.
That collar is always a red alert re inspection as they do corrode and come apart.
Did you put your probe into the clean side, should have got a solid ~20.9
Id never mess with the hex, they are often greenish around the union- but dry.
Trying to tighten will end in tears- probably lol

 

[Subby]

yeah clean side was 20.8 and no readings for CO
the inner flue CO kept rising past 600 so I took the probe out to save damaging my analyser

 

[newcastle phill]

As the sampling point is above the collar - id bet a weeks wages (around a fiver af tr er tax Mlud) that its recirculating dirty air

 

[newcastle phill]

Im presuming you inspected the burner (took it out) and looked for splits/defects and the injectors were clear of lint and dust etc

 

[newcastle phill]

You did check the system pressure ? After purging the water lol

 

[Subby]

Yeah i repressured to 1.1 bar. I had isolated and drained most of the boiler so only splashed about half a pint everywhere.

 

[newcastle phill]

All you can do is get your volt meter out and follow the mi and check for power to gas valve etc one collar fixed.
Hopefully the water hasnt buggered something @

 

[Subby]

As the sampling point is above the collar - id bet a weeks wages (around a fiver af tr er tax Mlud) that its recirculating dirty air

I hope so it is an obvious fault.

Im presuming you inspected the burner (took it out) and looked for splits/defects and the injectors were clear of lint and dust etc

I removed casing, inner case, burner door, fan, burner, cleaned burner, injectors etc with hand brush and hoover. there was a fair amount of dust in there. (amongst all the cremated insects)

Thanks I will have my multimeter with me tomorrow to check the parts.

 

[Subby]

and maybe the mrs' hairdryer lol

 

[kozak1968]

Ring baxi technical. It can save you time in the long run.

 

[Subby]

As the sampling point is above the collar - id bet a weeks wages (around a fiver af tr er tax Mlud) that its recirculating dirty air

You have your fiver sir! The new collar did indeed get the CO to a good level. I changed the collar and the O rings behind the pump, filled her back up and she fired first time! Analyser readings were spot on too.

 

[kris]

Well done subby. It will be the first of many pull hair out days lol. Least u conquered