Potterton Suprima 80L flashing green LED from cold

[ismith]

This 4-year old boiler has been an on-going headache in my new-build home.

Under warranty most of the heating system seems to have been replaced to fix a red LED shutdown problem: Myson flow valves, wiring, thermistor, 2 controllers (Siemens)...

It was fine for nearly a year and now the flashing green LED light comes on after maybe a minute from cold in the morning. It takes 2 hours to get the radiator water up to temperature and then it works fine all day.

I've felt the outlet pipe on the boiler and it doesn't seem to get overly hot when it shuts off. I did try opening the (19) radiator balance valves to increase the system flow, just in case, but that doesn't seem to have made significant difference.

Any suggestions? Thanks.

 

[ismith]

Forgot to say that I have a standard hot water tank on the system too.

 

[Agile]

It sounds as if your pump is not working or not working properly.

Tony

 

[Baxmax]

Thermister control on pcb

Replace pcb 5112178

 

[ismith]

Thermister control on pcb

Replace pcb 5112178

That sounds not cheap.

Any chance the PCB is repairable, or is it a design fault?
(I can solder and source parts.)

 

[nickso]

just replace it and bask in heat.

 

[ismith]

Thermister control on pcb

Replace pcb 5112178

Have replaced and it's working fine now.
Old PCB was also Rev.3. Is this a common fault? Will the new one last?

Thanks everyone!