Glow-worm economy 50 works with cover removed only?

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