potterton suprima 40 tests before PCB replacement

[jonhind]

Hi all,

I have a potterton suprima 40 with a lockout fault.

I have read about all the problems with the pcbs and I think this is the problem but I want to be sure before splashing out all that cash.

The boiler ignites ok and runs for anything from 2 minutes to a few hours and then inevitably fails with the flashing red light, occasionaly it trips the mcb.

I believe this fault could can also be caused by the air pressure switch or overheat stat.
I would like to check these to confirm they are ok. I guess for the air pressure switch I only need to link it to close the contact to simulate it operating. As for the overheat stat I would think it is resistance based any ideas what resistance it should be at ambient temp (21 c).
Is there any other factor that may cause this lockout that i should check prior to replacing the board, i believe the ignition gap can also cause a lockout problem but as this fires up ok i have ruled it out.

I know cet do recon boards, can anyone recomend any where else.

Any info would be greatly appreciated.

Thanks,

Jon

 

[chrishutt]

Have you checked all the previous threads on Suprimas on this forum? If so, you may find suggestions on how to proceed. I doubt whether anyone has anything new to add.

 

[jonhind]

hi, yes i have been through the majority of the previous threads on this subject. Almost every one says that the pcbs are a known fault and should be the cause of the problem but none of them talk about the checks on the sensors I have asked about in the post.
It seems there is not many people who go through a step by step diagnosis, they just assume its the board and replace that first. I would prefer to test these devices and ensure they are operating correctly before spending out on a new board for £150 when it is just a £5 sensor as it looks like a few people have done in the past.

 

[MANDATE]

Jon, Checking the air pressure switch has been mentioned before, but not easy to find, and it's not a job for a non Corgi.

 

[ollski]

hi, yes i have been through the majority of the previous threads on this subject. Almost every one says that the pcbs are a known fault and should be the cause of the problem but none of them talk about the checks on the sensors I have asked about in the post.
It seems there is not many people who go through a step by step diagnosis, they just assume its the board and replace that first. I would prefer to test these devices and ensure they are operating correctly before spending out on a new board for £150 when it is just a £5 sensor as it looks like a few people have done in the past.

Thats because it is usually the pcb when you are talking about the constant reset every morning and various points throughout the day when it otherwise works ok. Electrodes and stats tend to give a more regular fault. I've changed 100 suprima boards this year and 2 fans and so far I have never had an electrode or stat fault.

 

[jonhind]

Thanks for the info guys

 

[gazthepottertonengineer]

i must just say that alot of the problems are with the electrode leads and as they come with the new kit they are resolved when the pcb kit is fitted but it might be worth £2.00 just to try it before spending £150.00 on the new pcb upgrade kit 5111603