Potterton Suprima HE Now Power (suspect Honeywell PCB Code 5110550)

[WSB]

Hi,

Our ten year old Potterton Suprima HE suddenly has no power going to it.

Checked mains supply and all is good.

Removed the Honeywell PCB Code 5110550 and all looked good and dry inside, however around some resistors close to the relays there are scorch marks on the PCB.

My suspicion is with this PCB and am tempted to go out and get a replacement (about £200 each, unless someone can recommend a cheaper supplier?).

However, I don't want to go and do this if it won't completely solve the problem.

My main question to this site is, do these PCBs just stop working and if so, what are usually the causes?

I can understand if there was some water leakage getting in there but it all looks clean.

Any ideas folks. Thanks in advance.

Cheers
Lee.

 

[ScottishGasMan]

No DIY Gas Advice on this forum

(and yes the PCB is directly affecting the gas saftey on the boiler so does count as DIY gas)

 

[WSB]

Thanks ScottishGasMan.
I'll speak to a heating engineer.
Just out of interest, in your experience, do these boards just fail due to component failure or can something external within the boiler cause these PCBs to fail?

 

[ScottishGasMan]

Yes and yes. PCB can just give up. But other faulty components can just as easily take em out.

 

[WSB]

Ok thanks.
Would be a shame for me to replace the PCB (NB: I am an electronic engineer) only to have something external blow it again.
I'll get my heating engineer to take a look.
Thanks

 

[bernardgreen]

A common fault on these boards was failed solder joints on the pins for the connectors onto which the cabkes were connected. The hole was over size for the pin, ( for ease of assembly ) and there was no clamp on the cables to absorb vibration. Hence the solder bridge between PCB tack and pin took the vibration and eventually failed.

The board design was changed some years ago and the cable loom, supplied with the new design of PCB, was soldered to the board without connectors. Strain relief / vibration damping was included to protect the solder joints.

 

[WSB]

Went and bought a replacement PCB and had it fitted by my heating engineer mate.
We're both sitting here a bit perplexed as still no lights show up on the PCB............

 

[hertsboilers]

Went and bought a replacement PCB and had it fitted by my heating engineer mate.
We're both sitting here a bit perplexed as still no lights show up on the PCB............

As you are an electronic engineer. Did you check live and neutral, also switched live, to both PCBs, old and new?

 

[TCCHeating]

Went and bought a replacement PCB and had it fitted by my heating engineer mate.
We're both sitting here a bit perplexed as still no lights show up on the PCB............

Electronics engineer and a heating engineer both stumped

Basic checks should pinpoint the problem!

This wreaks of a bit of bs.

You sure your heating engineer friend is not imaginary?

 

[Agile]

I am surprised that an electronics engineer would not have at least measured the mains voltage at the input pins on the PCB and told us the result!

Would not always be so surprised if the heating engineer didn't though.

So what is next?

Its too far for me to go though. [ Keeping quiet about my visit to Eastleigh tomorrow! ]

Tony

 

[bernardgreen]

There are people employed as "electronic engineers" who do little more than follow a diagnostic flow chart or check list and then change the electronic module that the diagnostics indicate as being the failed module. They have little ( if any ) actual knowledge of electronics. Service technician would be a more appropriate title / job description.

 

[igNOArant]

Yes.