Baxi Solo 3PF - blowing fuse

[Squealer]

Hi all.

I wonder if anyone can offer some help in diagnosing a problem with my boiler? It’s a Baxi Solo 3 PF and keeps blowing the 3A supply fuse when a call for heat is made. Initially I thought it might be a problem with the wiring, pump or valves. However, I’ve tested the pump and that appears to work ok and I’ve now tried the boiler without the programmer and just the pump, permanent and (temporary) switched live. The boiler now powers up and runs the pump but doesn’t fire or run the fan and blows the fuse when the thermostat knob is turned beyond about 1/3 travel. The potentiometer tests ok on a meter when disconnected.

Any help appreciated.

Many thanks, Paul

 

[chrishutt]

Test the fan. It's the first thing to start up in the boiler. Until the fan has established an air pressure differential, the gas valve, etc. are not energised.

 

[gstens baxi]

I agree. The fan is definatly a suspect but it could also be the pcb.

 

[B.O.B DOLE]

what you want to do is remove the live wire to fan and see if it blows if it does remove the live to pump if it blows remove the live to gas valve . at this piont you have elimanated all componants with windings which normally blow the fuse if they where nackered if you know how to do a resistance test try that
from my experiance you will find its always the pump

 

[Squealer]

Hi guys,

Thanks for the pointers. I isolated the fan and that stopped the fuse blowing. I checked the harness which was ok and then pulled the fan assembly out and it looks obvious that's where the problem is - one of the windings is burnt to bits!!

Thanks again for the prompt help.

Paul.