Vokera mynute 20E

I had a problem with my 14e whereby the unit starts up running then the burner cuts out, red light on (flashing) and the fan continues. This was repaired by replacing the ntc thermister. My sisters unit has an issue now, turn on unit, fan runs pump runs, no burner. Changed thermister , no change, swapped PCB and overheat thermister, runs for aa few mins, cutout, fan on pump on and red light on continuesly. reset and it'll go through the same process.
Any ideas, I have the luxury of being able to swap parts with my own boiler.

So you're saying that before you changed the parts it didn't light at all, but now it does, for "aa few minutes"?

Heve you tried her pcb in your boiler (!!)?

Hi Chris
I changed over the PCB and the boiler comes one, burner lights for a few mins, shuts down (fan running) red light on continuosly, burner does not light up again. Same again after reset.
I'm thinking the microswitch that is attached close to the pressure diaphram at the vent might be sticking.