Baxi System 100 HE Plus

[uplandsplumb]

Hi there all...

Im having a problem with the fore-mentioned boiler...

Firstly, I was called to a customers house who had a overheat problem...

Having realised the high limit stat sited on the side of the fan unit was breaking continuity I sought advice from baxi tech (as I had no previous knowledge of this boiler and no paperwork at location) who advised changing door seals which i duly did... Then tried it again sure enough five or so minutes and it locked out again... So then i changed burner as the ceramic plate had come loose from burner (which had warped) and was lifting on high burn..
I also changed burner bottom plate as the seals were knackered and was advised that it came as a complete kit.
Ok so I fire up whilst holding breath only to find that electrode/ignition now knackered despite light clean...
Finally, today I retry and after a few minutes I can start to smell the boiler getting really hot... Then again it locks out on the high limit stat sited at fan... ok so I understand products of combustion must be pulling down ito the fan unit but how???? The flue is clear ... The heat exchanger was initially looking like it had never been cleaned although I obviously now have... Also the boiler seems to be loosing pressure quite frequently bit I can't see any signs of leakage anywhere on boiler or system as a whole..
All I can think of is to change the heat exchanger and all the seals again.
The costs are starting to go through the roof as far as the customer is concerned and there's no guarantees that this will solve the problem...

HELP...lol

I would be very grateful of any ideas etc

 

[Billy Bob Bob]

this boilers a nightmare,same shed as baxi barcelona he and baxi solo he i would put them on to heat team or change boiler sorry this does not help but it is a full shed

or burn it

 

[Toddyplumb]

When you say door seals , you changed the red combustion chamber seals not the seals on the outer door wth the 1/2 turn screws

 

[uplandsplumb]

Yes I do mean the RED seals on the chamber door...

 

[Toddyplumb]

That usually sorts it ! Try changing the stat itself
Mind you I did have a solo HE that was doing this and it turned out to be the board !

 

[mikegas]

could it not be the heat ex is leaking and running into condense trap and away with the condense therefore no visible leak

 

[uplandsplumb]

Yeah im thinking it may well be... I think the H/exchanger is knackered as I found quite a bit of debris at the back of burner chamber when I replaced the seals... Have spoken to customer at length and she has decided to rip it out and change with new viessmann 35kw.. So that will be the end of that... Shame though in one way as would have like to find out for sure...
Thanks all though for your advise....

 

[Billy Bob Bob]

heat exchangers are prone to problems on these even from new so its no loss

 

[oldplumber]

makes repair by replacement take on a whole new meaning!!!

 

[uplandsplumb]

Ummm not sure what you are trying to say "Old Plumber" but thank you for your comments... Even if they are meant to be sarcastic...