Potterton performa 28 not performing !!

[AndrewAndrew]

Please, someone help.
I have the above boiler which stopped working. The PCB, gas valve and modulator have been changed in an effort to fix. The gas pressure will not set to the minimum pressure however it is adjusted. The gas valve was not a complete unit when changed, the adjuster tube was transferred from the old one. Are there different valves i.e manual and modulating for this boiler, has the wrong one been fitted? The flame is either all or nothing.

 

[corgiman]

Was it a CORGi person who changed it?

strange that it cannot be adjusted for min pressure

sure jason or gaz will know what the score is

 

[Agile]

I seem to remember that there is a version of Baxi/Potty without a mod coil which uses one of the solenoids and has a min/max on the PCB.

Although these boilers all look very similar there are several differences to be wary of.

Tony

 

[AndrewAndrew]

Yes it was a Corgi registered person who changed it. He doesn't know why the pressure can't be set so I thought I'd ask the experts. The PCB that was fitted was an upgrade from the original part but would that make a difference.
It's good to know people are willing to help, I look forward to further input. Thanks

 

[Agile]

I always try to replace like for like on those as there are so many minor variants.

There is a "later" version of the PCB with the earth connection lead on the opposite side but otherwise its not much different.

I suspect that the combination of parts or installer are not compatible.

Tony

 

[AndrewAndrew]

Further information - when you remove one of the wires to the modulator the voltage is supposed to drop, it doesn't.