Suprima 50 HE No lights unless Gas Valve disconnected?
Hi,
I have a Suprima 50 HE boiler that decided to stop working yesterday. When I got to it, all 3 lights were on and so I followed the usual instructions and reset the temperature control knob. All goes well and the boiler fires up and I walk away.
About 10 minutes later (or so), we notice that no heat is coming through so I check the system again. This time no LEDs are lit at all. My corgi plumber friend checked the system up to the PCB and we could see mains power getting to the PCB fine. Diagnosis... Faulty PCB.
So, today I pick up a new PCB, fit it, and the same issue is present. I checked the harness and the rest of the system and all looks well. As I was pulling out the harness connectors from the PCB, I spotted that the system came into life as I disconnected the Gas Valve. The green light indicating Mains present is lit, and the middle green led flashes. The system tries to start up for a few seconds, and then stops. This process continues. I shut it down and started looking for help as my plumber friend is stumped.
Hi Bryn, exactly the same is happening to me today?
Changed the PCB and the gas valve and checked continuity on the cables between card and valve and theyre OK?
If I pull the valve plug from the card, the start up sequence initiates, and I have tried to trick it by quickly plugging in again when I hear the click (for valve open supply), it runs for a few seconds more (no ignitian strikes) and then all lights out again.
You got any further?
Tony Salter
December 2012
Small update. For some reason the power now seems to be ok according to the right hand green light. On demanding heat, the burner lamp is flashing, the system is trying to start up but no success after 5 goes. Red light on for lockdown. Reset and same thing happens...
Bryn Faulkner
December 2012
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