o the cover it turns on perfectly. When I replace the cover it does not go on. I removed the intake line and inspected it, and it is clean. Seems like some sort of pressure sensor. But it runs without the cover????
Tools & Hardware - Others - York - Furnace Draft Inducer Blower Fasco # A224
Answers & Comments
I would suspect the air pressure differential switch. It looks like a diaphragm with a piece of tubing running to it and a electric switch mounted on it. Before changing it though, check that the condensate drain trap has water in it. I know that sounds silly, but if there is no water in the trap (if it's desperate from AC trap, then it can dry out in summer) you can be pulling air through the trap, and not enough pressure differential to trip switch. Also be sure the intake is clean outside. If there is any kind of Screen on intake be sure it's open. You can test switch with tester to see if it is the problem. The switch should close after the draft inducer fan starts.