Hello, I have an older 80s model Magic Chef furnace - G83-75D-5. The furnace worked fine all last winter. I put in a new air filter in prep of winterizing and now the unit will not come on. The paperwork says to be sure the door is replaced correctly due to the safety interlock switch... I have taken the door off and put it back on serveral times with no luck. Any suggestions?

Thanks so much.
Pam

The door switch is made to kill power to the furnace if the door is removed. That way no one can get hurt if the system kicks on with your hands in it or get into the electric accidentally. Switches do go bad. If you know the door is in right you can try bypassing the switch to see if it will work. You have to turn power to the system off first and the join the two wires together and see if it works after restoring power. To bypass a safety switch permanently is never a good idea.