Potterton Puma 100e no H/W or CH and burning smell?

[Caspar]

Had heating on and noticed rads getting cool. Went to garage and noticed strange burning type smell. Tried HW and not working either. Checked Modulation PCB (as I replaced it a year ago) but looks fine - no sign of burning (as do the other 2 boards).
When a tap is turned on or CH the boiler makes a buzzing noise but never ignites flame. The red LED on PCB lights when calling for water but not CH.
Pressure gauge is normal and no warning lights on.
Any ideas what's happened?

 

[Rob]

Where does the buzzing noise come from?

 

[baxpoti]

Does the fan run..................or not?

 

[Agile]

Does the pump run for that matter?

If pump is on but not fan then its probably the ignition PCB on the back. They fail are the ratio of about 30:1 to the main pcb.

Tony

Edit, sorry forgot about that smell. There is a particular special pump- smell! Almostly certainly that. It may be too hot to touch too.

 

[pannierstan]

Is the pump running as they can smell really good when they go or stick and buzz.

Stan

 

[Caspar]

Thanks for the replies.
I took the cover off to see the fan. The fan doesn't seem to be running even when CH or HW are on. The pump does seem to run (put a screwdriver on it and other end to my ear and can hear a whirring noise).When I undo the black screw thing on front of pump and turn pump over it feels ok.
Presumably the fan should run all the time?
The paper type covering on the winding of the fan motor does seem to be a bit dark brown stained - I wonder if it's burnt out?
The fan does turn with a screwdriver though.
Is it the fan or the PCB that controls it? Or something else.
Thanks again.

 

[baxpoti]

With demand on the fan should run.

Using a multimeter test for voltage at the fan with demand on....230v?

 

[hav it]

PCB PCB PCB

 

[Caspar]

Thanks.
I'll test tomorrow. So if i find 230v at fan then the fan has gone - if no voltage then it's the PCB? Right?
Any recommendations for Potterton spares suppliers?

 

[Caspar]

Well I have found voltage at the fan so looks like the fan has had it?
Presumably a broken fan would stop boiler working completely?
Thanks.