Potterton Prima 40f won't fire pumps gas out flue indefinitely!

[MDS PLUMBING]

Hi all, I was called to a job where national grid had turned boiler off due to smell of gas. ( He actually only turned the isolator off surely they are supposed to cap)??

I havent worked on one for a while... They have pcb but do they lockout?

I am sure the ignition failure would explain the gas pumping out the flue but surely it should be cut off after there is no flame unless control is failing to danger!

Any help appreciated.

Dave

 

[diamondgas]

Hi Dave,

The prima F just keeps on pumping gas to the pilot supply! If it isn't lighting then you need to be checking ignition related stuff but only if you're gas safe registered IMHO

 

[MDS PLUMBING]

Thanks diamond gas! Just to clarify I am gas safe registered - 537729! I loathe the illegal engineers as I am sure you do. I am still fairly new to it all though! I work for letting agents at the mo and they all seem to be back boilers, ideal classics or new combi's.

So is there no ignition lockout on these? I will check the obvious, pilot assembly etc. The jet is obviously clear as it getting gas. I would have just thought that it should give up after so many attempts / 1 min?

Thanks again,

Dave

 

[diamondgas]

Thanks diamond gas! Just to clarify I am gas safe registered - 537729! I loathe the illegal engineers as I am sure you do. I am still fairly new to it all though! I work for letting agents at the mo and they all seem to be back boilers, ideal classics or new combi's.

So is there no ignition lockout on these? I will check the obvious, pilot assembly etc. The jet is obviously clear as it getting gas. I would have just thought that it should give up after so many attempts / 1 min?

Thanks again,

Dave

It's good to build up a portfolio of boiler manufacturer's instructions Dave. I have a library of PDF's ... None of us will ever know them all ... This boiler has a much less complicated ignition board and will continue attempting to light the pilot indefinitely! The gas valves are prone to letting by so I'd be testing for that too just to be on the safe side. Most likely its an ignition issue though. IMO

 

[jtsplumbing]

Have you got a spark or is it just clicking on board ?? may be faulty lead.

 

[huddster]

had this before with this boiler - leaking pump above the boiler onto pcb shorting to earth so the board thinks rectification has taken place and holds gas valve open (or something or long those lines) im sure there is a safety notice regarding this problem.

ended up drying out and replaced board as precaution

 

[bright spark]

I had the same with a leaking auto air vent above the boiler, water got onto pcb and gas valve was allowing 'raw' gas to be blown out through the flue. Very worrying. Told customer to relace the PCB. They had lost faith in the boiler by then and wished to replace it. Which I did!