Following the fault dianostics, given a fast flashing red lamp, on J flowchart in the owners manua (The fan not running) I checked the air pressure switch(open circuit) ok, and fan primary winding (100 & 50ohms)ok, checked for 240v at st1 on the PCB for both heating and HW call (no voltage detected), and as directed changed the PCB but the fault still persists.

Switched the boiler on and the fan ran momentarily, stopped and the red lamp again began blinking rapidly. I repeated the above test giving the same outcome. i.e. no closer to rectifying the problem. I subsequently contacted Worcester Technical and they pointed back to the PCB?

NB: Great care was taken to avoit static disruption when fitting the new PCB. Firstly, has anyone experience this type of fault; and secondly, has anyone fitted a new PCB for this boiler and found it to be faulty?

Deni M., January 2006

had same last week, fan shaft runs in bushes/bearings and tightens up slowing the fan down, down to stop thus not making the differential pressure switch, changed fan unit comlpete £102.95.
been running ok since.

phil.parry, March 2010

This guy says mine is a PCB problem too.

He is saying a new PCB is £100? (labour on top)

Is this right or is he takng me for a ride?

Mo, April 2008

I had the same problem and on the instructions of a plumber changed the PCB-Same problem.
Worcester technicians came next day and changed the fan unit-Problem solved. and the boiler has been running perfectly ever since!

John Hayes, January 2007

Did you get this resolved??

SP, February 2006