potterton suprima

[mushio]

Hi
I have a potterton suprima 50.This boiler has given me problems for the last 18 months. The latest problem is that when the heating system is switched off by the timer,the water pump keeps running. Today i changed the pcb, But this has not cured the problem.

 

[Agile]

In that case I would wonder why you changed the PCB ?

How much experience of diagnosing boiler faults have you?

Tony

 

[Slugbabydotcom]

Extract from the manual :-

Pump Overrun
The boiler controls operate the pump for several minutes
after the shut down of the boiler to prevent overheating. The
boiler controls will also operate the pump for a few minutes
every 24hrs, to maintain the free running of the pump.

I wont give you grief over it as I seem to learn everything the hard way myself.

Todays lesson is :-

READ THE INSTRUCTIONS

 

[mushio]

Hi
Forgot to mention.Also the boiler fires up every now and again,and runs for aprox 20 seconds.It seems never to fully shut down.
As far as the pump is concerned,it runs for hours after shutdown.
I know that they are suppose to run for a few minutes to prevent overheat.
Thanks

 

[corgigazza]

The two port valves may be faulty, they have a habit of the micro switches in the valve head fusing shut causing the system to run with the valves shut and the water going round the bypass. turn off power test continuity between gray orange wires(removed from wiring box) on both valves, should be open circiut when shut. closed circuit when open.

 

[mushio]

Hi Gazza
Thanks for the help. I checked the 2 port valve,and when i took the cover off,a small piece of plastic fell out. The switch operated intermittently,keeping the pump running,sometimes all night.
I will replace the valve.
I might change the pcb back to the original,but it looks like it got hot in a few places. From hearing what people say about these boilers,the pcb is a bit of a achilles heel.
Once again thanks.
Martin.