Potterton Prima F 50 Boiler problem

[hsvirdee]

I have a potterton prima F 50 boiler. When either the central heating or hot water come on via timer or 1Hr button, the pilot light comes on but the main burners fail to ignite. The fan is working is working. Thie is intermittent problem in that some days the boiler might work ok, but generally it fails.
The pump is working ok, the mid 3 way valve has been replaced, and the Main burner solenoid in the boiler has also been replaced, by the heating eng.

Sometimes pressing the (pilot)button underneath the bioler ignites the main burners. Agin either main burner stay ignited or go off.

Help ?

 

[ChrisR]

On the face of it either the pcb isn't giving the right signal to the gas valve to open, or the gv, despite the new solenoid, isn't opening. Could be either. If standing in front when it did it, one could determine, using a meter.

 

[hsvirdee]

By testing with a meter, will it definately determine between gas valve OR PCB ?

Also how difficult is it to replace either ? ie can I replace the gas valve by just undoing the screws on the both sides of the valve, rather than undo the pipes ?

 

[Rob]

if your gv is receiving the correct voltages from PCB then theres not alot else it can be, although the solenoid would be an obvious thing to change, so maybe a fault lies with the amerture itself.

 

[Agile]

The whole question is if the main solenoid is being powered!

If so the GV is faulty.

If not then the pcb is not reacting to a flame detection and will probably still be sparking too.

Tony

 

[ChrisR]

Don't try to change the gas valve yourself, get a corgi if it's that.