CH Boiler resettable fuse

[Gyn_Paul]

Anyone out there with a Franco-Belge gas boiler? If so does the little resettable fuse (under the screw cover) on the front panel actually 'click' when reset?

In one of the houses I look after, the boiler was out (as was the pilot), and the circuit to it dead. organised temporary volts (until I find where the fuse board is hidden) re-lit the pilot, but still no life. Given that it's a combi, I would expect it to fire up and heat the DHW even if the room stat wasn't calling.

I'm beginning to think the house has had some sort of storm 'episode' as the boiler would be the only thing not unplugged during the owner's absence.

So anyway, the resettable fuse thingy pushes in, but does't feel like it's resetting anything. is this right?

[napoleon]

I have a Potterton gas boiler in the UK. Over the years I have solved several internal control problems, some involving the safety cut out.

If it really has cut-out due to fault I feel a clear, positive, mechanical "clunk" as it is pushed back. On other occasions I have pushed it in just I case it has tripped and I feel very little although there is a significant movement. I would assume your boiler has not been tripped and is ready to be fired up if the rest of the system is operational.

When you say it is dead, do you recognise this from a lack of electrical indicator lights? The only lights are on my external control/timer unit with nothing on the boiler. Also, most boilers have pilots that only light when heat is called for. It appears your boiler's pilot remains on continuously.

Is it so dead that the fan and/or the water pump do not come on at any time?

Hope you are able to find a simple answer.

Alistair

[Gyn_Paul]

Yes, thanks for that. A bit more investigation leads me to think that there is nothing wrong with the cut-out - as you sat, the button moves in and out with no resistance which I think would be the case if it was latched and working. Volts to the spark generator to light the pilot, and available on various connectors, but without a proper circuit diagram to do a proper fault find, I think I'll leave it to an engineer.

On the subject of pilots... I think you are confusing the two systems:

older types have a PERMANENT pilot, which serves both to light the main burner, and (via the thermocouple) permit the gas valve to open on demand.

With the other type, the burner lights each time with a spark which continues until some device (a type of thermocouple I assume) confirms the flame is lit at which time it either stops sparking, or shuts down.

[napoleon]

Our Aga in the UK has a permanent pilot and many of our old CH boilers also had them. Our 25 year old Potterton has a pilot that only lights when the burner is required to run. It has a cunning photo sensor to check that the pilot has lit before opening up the main burner.

Does your boiler have any timer control unit, either internally or externally?

Have you tried giving the valve control block (casting) a sharp tap with a hammer? Sometimes the solenoid controls stick and defeat normal fault finding. Not much help . Sorry.

Good luck!