I like to take things apart to see how they work.
That's a picture of a relay from our furnace. I'd replaced the motor, the wiring to the motor, and fiddled with it for several hours...taking the motor out, putting it back in, checking the wires, swearing, sweating etc.
Turns out there were three things wrong (a) motor was burned out, (b) relay contacts had fused due to overheating when the motor burned out and (c) a separate inline switch box had popped a fuse. There's a circuit breaker for the motor and controller in the main service panel and a separate inline switch box with those old screw-in type fuses as well.
Now that I got those three things fixed we have heat!
I still have to go to the store and get one of those old screw in type fuses, put new air filters in and watch the belt and motor for awhile to make sure they continue to run smoothly.
The tag on the old motor was dated 1940 so I guess I got my money's worth out of that one.
Anyway that picture at the top is a relay from the controller. The controller is a neat piece of machinery, it's an old Honeywell unit that's built like a clock, with lots of little pieces. As the heater warms up a thermocouple heats up, energizing a coil which pushes a rod on that relay to turn the fan on. It was interesting to take it apart and figure out how it worked.
If you ever need someone to come over to your house and sweat and swear..just give me a call. I'm pretty good at fixing washers/dryers/furnaces too.
