my Glow-worm 50 stopped firing up when heating was called for.the fan is fine and the sensor tubes were blown through and it started working fine.however when i replace the outside cover it stopped responding again.took it off and its fine...any suggestions

john walsh, February 2013

its a fault finding issue u will need to eliminate each issue to find the problem. by opening the cover u are allowing an increased amount of air into the chamber so u get a higher airflow causing the air pressure switch to operate.
it could be as follows.
1) check voltage at fan see if its getting 230v . if its below 200v its a fault control board not allowing the fan at full as it should.
2) faulty air pressure switch
3) blocked holes where the plastic tubes join on to give these areas a good clean as a reduced flow will affect it.
4) worn out fan not sucking enough air

kash, February 2013