Fan center relay Tyco 57-01V18BC3E218

maxfrese

Hi,
We have a Thermo Pride OC5 oil furnace. Today we replaced the blower motor that worn out. We made sure to label all the wires so as to reattached correctly. We also vacuumed the flue and clean out ports. We turned on the heater and both the burner and fan come on and shut off correctly. We thought it was fixed. Then when the heater cycle was done and both the burner and fan were not running we heard a humming sound coming from the fan center relay area. With the heater not running, we disconnected the power supply the humming stops, plug it back in comes back. It kind of sounds like the contacts are frozen closed. We tapped on the relay but that didn't change anything. Now, we're not sure if the sound was there before we replaced the motor. Any thoughts?

billtwocase

Sounds like the step down transformer humming. Does it still work as it is supposed to? Make sure L-1 and L-2 are not switched. Some 24 volt transformers just hum. It would certainly burn up if it was not wired right.

maxfrese

Thanks