Main 24 HE burner failure

[tonyacktar]

Just been out to see a Main 24 HE which fails to spark/ignite.

Have followed fault finding sequence, fan runs, airflow switch proved but the PCB is not providing 240v to the
gas valve (connection 37 and 38). Have also tested the rest switch. I am 99% sure the PCB is faulty is there any other test i can do to be 100% sure.

If PCB was not faulty would the voltage be present at connection 37 and 38 during start up and until boiler goes into failure mode


many thanks

[Hardy1]

isit a new boiler?, cause funnily enough i was out with a gas safe engineer 3 days ago, and had exactly the same problem, it was just the purge volume of the run that had to be calculated and it fired like a piece of art, from what ive heard recently there is a faulty batch of main 24's out there with manufacturer's faults so people watch your backs. o and check the electrodes are working and the air vent is open on the pump and top.

[diamondgas]

Are you getting a spark tonyacktar? and lights flashing? ...... you've described some of the process the boiler goes through but haven't mentioned whether it locks out and what indicator is showing?

[Hardy1]

fault code E133?

[gas man]

band a or b they are mechanically different,and have you checked for reversed polarity

[Poxi]

Just been out to see a Main 24 HE which fails to spark/ignite.

Have followed fault finding sequence, fan runs, airflow switch proved but the PCB is not providing 240v to the
gas valve (connection 37 and 38). Have also tested the rest switch. I am 99% sure the PCB is faulty is there any other test i can do to be 100% sure.

If PCB was not faulty would the voltage be present at connection 37 and 38 during start up and until boiler goes into failure mode


many thanks

How did you test the APS with a meter on continuity or suck it and listen for a click..PCB`s are pretty safe on these now.

[Poxi]

from what ive heard recently there is a faulty batch of main 24's out there with manufacturer's faults so people watch your backs.

Really...Do tell more im intrested

[gas man]

Really...Do tell more im intrested

well i have not come across that,2 reasons why pcb,s go on this boiler
1,halfwits who reverse the polarity then wonder why the boiler keeps going to flame failure
2,water leaks from the heat exchanger o rings if over pressured ,but this will see off a 105 instant with the Siemens pcb but on main 24/30 he with the Honeywell pcb you have a chance of drying it out and saving it....sometimes other than that they rarely have pcb failure this is the reason i asked the op if its a band a or b is because if its a band b he may have aps failure

[Hardy1]

Really...Do tell more im intrested

well went to a job with a engineer, and he couldnt couldnt figure it out, it was a new install we had been called to, the guy that installed it was on holiday(dont ask), and run all checks e.t.c, so rang up the guy the customer bought it from and he was like do this and that blah blah blah, and then in the end he was like well ive had a couple of complaints about these exact make same problem and then he goes manufacturers fault on a bunch of them, but then there was me thinking, while my engineer mate was on the phone and i took the gas pipe fitting of the elbow to the boiler and purged the pipework for atleast 5 Minz ( i fink), and all i could smell was air not gas so i was like :S :S :S :S :S :S,(engineer not even looking at me lol), and then i smelt gas properly so connected it all back up and it fired perfectly, what it was, was like 32mm PE pipe had been used for the run outside (obviousely) and then 28 inside reduced to 22mm to the boiler, so all it needed was a good purge volume which i worked out and was fine, Engineer face was like :|, o what a good day he evn brought me 3 pints after work for that.

[Poxi]

well went to a job with a engineer, and he couldnt couldnt figure it out, it was a new install we had been called to, the guy that installed it was on holiday(dont ask), and run all checks e.t.c, so rang up the guy the customer bought it from and he was like do this and that blah blah blah, and then in the end he was like well ive had a couple of complaints about these exact make same problem and then he goes manufacturers fault on a bunch of them, but then there was me thinking, while my engineer mate was on the phone and i took the gas pipe fitting of the elbow to the boiler and purged the pipework for atleast 5 Minz ( i fink), and all i could smell was air not gas so i was like :S :S :S :S :S :S,(engineer not even looking at me lol), and then i smelt gas properly so connected it all back up and it fired perfectly, what it was, was like 32mm PE pipe had been used for the run outside (obviousely) and then 28 inside reduced to 22mm to the boiler, so all it needed was a good purge volume which i worked out and was fine, Engineer face was like :|, o what a good day he evn brought me 3 pints after work for that.

Good Man

Cant wait to finish work tomorrow, Then will be on the pints all weekend myself

[Hardy1]

and i cant wait till all this revision is done and im doing my ACS then i will be sitting down with 5 pints of stella and a bottle of famous G on that friday for sure.

[cdodds2004]

yea check polarity, first of all, turn spur on and boiler off and see if you have 240 at the live