Potterton prima randomly turning on

[West Counrty DIYer]

As promised

 

[West Counrty DIYer]

As promisedView attachment 290398View attachment 290399View attachment 290400View attachment 290401

 

[West Counrty DIYer]

So some explanation may help:
Hive left cable permanent live and neutral, right cable HW on and CH on

Junction box:
Bottom left furthest left HW on and CH on, inner left permanent live and neutral.

Top left hot water tank

Top right mechanical valve

Bottom right go to the boiler.

 

[West Counrty DIYer]

Hi everyone, so I've tried something for fault diagnostic purposes. I electrically disconnected the motorised valve and used the manual override. Still have the same fault, so I'm thinking (happy to be wrong) that with the valve disconnected and the controller replaced, it rules out external inputs and it means it's a boiler problem.

 

[ianmcd]

Exactly how did you disconnect the motorised valves

 

[West Counrty DIYer]

I disconnected it electrically by simply taking the wires out of the junction box.

 

[West Counrty DIYer]

So some more info. A boiler guy came round yesterday and diagnosed the problem as a PCB, we've subsequently worked out there isn't a PCB. Now what are peoples thoughts? I was thinking about the pump overrun thermostat, I wasn't sure because how would it fire up the boiler. I am wondering if it's broken down and putting a live back though (via brown wire in the diagram below)

 

[ianmcd]

Contrary to your assumptions earlier your motorised valve does open on heating demand, when the Ghost on you refer to does the pump only run, or does the boiler actually fire at the same time ?

 

[West Counrty DIYer]

The boiler fires the valve on the HW doesn't open

 

[ianmcd]

The boiler fires the valve on the HW doesn't open

what valve on the HW ? that m/valve is wired into the CH on terminal on the hive

 

[West Counrty DIYer]

Sorry my fault I meant CH, the valve is on the CH