Potterton Performa 28i CH problem

[mit]

Can anyone help me with a CH problem on our Performa 28i?

The other day I replaced the DHW diaphragm (a job I've done before) because it had a hole in it.
I put everything back together and reset the boiler. Great, I thought, the hot water works. With the selector switch set to HW and CH I switched the CH override switch on the integral timer to 'on'.
Nothing. I turned the temperature control right up as well as the roomstat. Still nothing; no light on the control panel and no sound of anything at all happening.
I think I must have disturbed something somewhere, but I can't see anything wrong.
Are there any tests I can do to figure out what is wrong and eliminate what is working? Or perhaps it's something simple I've overlooked. Any ideas would be really welcome. Its getting cold!
Thanks

 

[jackthom]

Maybe not the most likely cause but as it's easy to check.......I'd have a look at the electrical connections into terminals 1 & 2 on the PCB terminal block in case they've been disturbed.

Perhaps put a wire link between the two to completely rule out any problems with the thermostat.

 

[mit]

Thanks for that Jack. I gave it a try, but no joy. I also tested the power supply to and from the various switches with a mains tester and they seem to be working. An other suggestions?
Thanks,
Tim

 

[Agile]

The obvious way to find the fault is to trace the mains input as it goes into the boiler.

I would be hesitant to recommend many DIYers to remove the PCB cover on that model though. Its very easy to damage something when refitting it.

Tony Glazier

 

[mit]

Hi Tony, I took the cover off the PCB cover to test connections when the CH didn't fire up. It's strange because after replacing the diaphragm the hot water works fine but the heating doesn't activate at all.
Something in the PCB perhaps?

 

[mit]

Anyone have any suggestions? Please!