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GB 142, flameout at startup.

flameout Member Posts: 1
I’d like to address what seems to be a not uncommon issue with this boiler. I had the issue of watching at startup a gentle blue flame would be blown out by what I observed through the site glass as a wind. It would cycle through properly but code 6A, repeat and eventually lock out. I tried lots of different ideas suggested by this site and reading the manual.
I admit the boiler needed cleaning which I paid for but got an unsatisfactory job. I did it my self several times after learning the proper way. This did not cure the issue but was necessary anyway.
Holding my hand over the snorkel loosely at startup would get it to ignite. This act cut down the “wind” allowing it to ignite. Once I removed my hand it would stay lit but you could see the wind return.
It seemed to me I needed to find where the extra air was comming from. I wrapped the top of the chamber to seal that gasket with tape. It would not ignite. Next the bottom plate. Same result. I removed the tape each time so I was only dealing with one variable at a time. I lit the boiler using my hand to cover the snorkel again. Next I gently pushed on the fan motor. This totally changed the flame and calmed the air down. I took the assembly apart as far as I could given my tools at hand. What I realized was, there is a rubber bushing between the motor and fan housing that had dry rotted and the source if the extra air. I replaced the fan/motor assembly and it was good as new.
Just to let you know I did check to make sure the boiler had the correct set up as far as resistance and air/gas ratio was concerned. That all checked out.
I hope this helps someone else down the road. I spent many hours cleaning it and diagnosing it. Good luck. Be safe.
IronmanMad Dog_2kcopp


    EBEBRATT-Ed Member Posts: 15,839
    Good to know
  • psb75
    psb75 Member Posts: 863
    The GB 142 is extremely sensitive about its air/gas ratio. I had similar 6A error code problems after 15 yrs. of flawless performance. Turns out...brittle air intake pipe, venturi and gaskets needed replacing. Used Bosch/Buderus tech support. Ordered Supplyhouse parts.
    Boiler is back to normal. Did heat exchanger cleaning using mineral oil "burnoff". Tedious. Then I also did a "scratch-scratch" with screw driver and hand tools to remove the "volcanic encrustations". Make sure condensate trap is clean. Also top burner element gasket gets old. Easy to get inside this boiler and its burner/heat exchanger. Also replace ignitor and ionization rods available through Supplyhouse.