Baxi 105E Instant problem

[ajelec10]

Hi, have a baxi 105e instant boiler, had a leak on the aav on the pump this in turn corroded the lower seal and bolt, whilst replacing the seal and bolt noticed a few drips of water coming from the upper chamber un done the cover and water pored out all the pcb( i had the power off). suspect heat exchanger? removed and checked all ok. looked out side and found a leaking gutter had filled the boiler up with water with the driving wind we have had! sorted it all new seals and bolt to pump and heat exchanger dryed pcb fired up bioler and all ok so i thought.
The problem i have now is will fire up in hot water mode then go into pre heat mode then in to heating fine, but some times it cuts out and the first light flashes saying flame failure? so ive changed the electrode (electronic thermocouple) and still no joy iam suspecting the pcb, but just wanted your advice before putting a new one in as the boiler works fine up till it cuts out?
Any thoughts welcome
AJ

 

[migoplumber]

i would think the pcb, if you got it as wet as you say. follow the bloiler flowchart fault diagnosis.

 

[ajelec10]

Thank you

 

[wnjswozo]

check flue for corrosion,smallest damage can cause all kinds of problems

 

[radswilldo]

Changing the pcb requires a safety check, the pcb is the "brain" of the boiler.

 

[ajelec10]

Thanks for all the replys, have sorted it now, it was the minium burner pressure not sure how it got affected in the first place but that was the fault when ever it went to low burn it would just cut out!! No need for new PCB!!
Regards
AJ