Baxi Solo cutting out - help needed

[DaveJ]

Hi all

I have a Baxi Solo (conventional boiler) about 10 years old, which has suddenly started cutting out. I go through the usual procedure to relight the pilot, switch on the hot water timer, boiler ignites but will cut out after about 50 seconds. The whole bolier switches off, pilot light the lot.
The flow / return pipes near the boiler are not hot, the pump is working, am I right in thinking it could be an oxygen starvation problem?

Any thoughts, help, much appreciated.

Dave.

 

[Kristoflampie]

Couple of possibilities here, its more than likely because the thermocouple is allowed to cool which then cuts the whole lot out. The pilot is being affected somehow , watch to see if the pilot is affected as main flame comes on and have the main flame gas pressure checked. If pressure is too high you get flame lift and can literally blow the pilot out as it lights up or pilot dips as main comes on and goes out which could mean the pilot pressure is a little low or is obstructed. These pressure checks can only be done by a CORGI qualified engineer in the correct discipline ie Domestic boilers.
Key is watch the pilot as it lights up, is any flame touching the thermocouple??

 

[PEDANTICVINDICTIVEMAN]

When was it properly serviced last, could be blocked flue ways ect causing oxygen starvation or just blocked weak pilot flame.

 

[DaveJ]

Thanks for the prompt reply chaps,

PEDANTICVINDICTIVEMAN: The boiler was moved last year by a Corgi reg'd company and serviced (although they didn't seem to have a clue what they were doing). Had the flue out last night, clear as a bell.

Kristoflampie:Makes a lot of sense. Looking through the pilot window the thermo couple does appear to be completly enveloped in the flame. I relit the pilot after checking the flue, did'nt switch the heating or hot water on last night and the pilot is still alight this morning but did shut down after 50 secs or so when I turned on the programmer.

If it was the boiler overheating would the pilot normally be extinguished when the thermostat kicked in? If not then I don't see it being a circulation problem (ie: blockage, air lock or pump). Which only leads to a problem with a thermo couple, gas pressure or something. I think this is getting out of my league, will have to get a Corgi guy in, unless you can think of anything elese.

Thanks for all your help.

 

[DaveJ]

Update: Boiler worked ok for a few days then started cutting out again.

Kristoflampie: said

Couple of possibilities here, its more than likely because the thermocouple is allowed to cool which then cuts the whole lot out. The pilot is being affected somehow , watch to see if the pilot is affected as main flame comes on and have the main flame gas pressure checked

Well I gave up in the end and got a GORGI guy in and the fault was a weak pilot light, changed it for a new one plus a new thermocouple for good measure and she's working like a good un again. so Kristoflampie your theory was spot on!

Cheers

Dave J

 

[Kristoflampie]

No probs Dave .......glad to help.