How can i fix my Glow Worm Space Saver 20 - 30F?

Hi Matt, The fan only starts when i blow into APS now. The system was making HW via timer ok but no CH unless as i said the MPV was in manual position - as soon as HW tank was full, call for CH was no longer firing boiler. I have used Glow Worms troubleshooting guide in the manual and that says the cable harness or connections to fan are faulty but i know thats not right because if i blow into APS 240v appears on the fan wiring - but not before i blow into APS. Can the MPV hold the system off if its faulty?
Thanks in advance
Steve

Steve Brown
November 2008

why are u blowing into the aps if the mid pos valve is faulty ?? if the fan is running the boiler is being told to fire

matt
November 2008