ideal mini c32 problem.need help

my boiler decided to stop working the other day.it would not fire up and the fan kept revving on and off.was told i needed a new fan, so bought one and fitted it to no avail.had a second opinion and was told APS so i bought one and fitted it ,to no avail.Funny thing is that when i link out the APS the boiler works perfectly.I ve cleaned the tubes ,venturi,cleaned the old fan and refitted it,cleaned the flue.Stumped every body even the tech team at ideal.Any body got any ideas whats up with my boiler.Its 3 an half years young.Any help appreciated.

The only person at Ideal who knows what they are talking about is Dave Kemp. Anyone eslse and you are wasting your time

Has the flue outlet pipe dropped out of its holder at he outside end?

ill check that first thing in the morning,i doubt it though i ve had that out and cleaned it aswell.some keep saying the pcb is faulting but if thats the case why does the boiler still work, minus the APS.

Got your aps connections/tubes backwards? We've all been there...!
Check the on and off resistances of the aps - should be less than a few ohms or more than 1Meg.
Is the aps actually switching?
Flue assembly errors are common on these, which is why it's Corgi territory

Alos check that you have correctly fitted the wires to the APS and that the test points on the top are sealed with the little plugs.

How long is the flue?

On this model the APS operation is often quite marginal.

How did you clean the venturi?

I once went on behalf of another CORGI who had failed to find the fault. There was a minute piece of spiders web inside the venturi which he had failed to spot.

I would measure the pressure differentially on the test points and expect to get about 2 mB. Must be more than the operating value of the APS !

Tony