The first thing that is supposed to start when a furnace starts up is the draft inducer.
Carrier furnace inducer motor does not start.
If the pressure sensor switch does not sense operation of the inducer motor within 10 seconds however the processor aborts the start up sequence and the burner does not light.
I have performed the equipment test.
If the draft inducer does not start then you probably either have a thermostat thermostat wiring problem electrical problem control board problem or a bad draft inducer.
The first thing that is supposed to start when a furnace starts up is the draft inducer.
This problem of getting a humming noise along with little to no spinning is very common with motors that do not have good quality capacitors.
I don t see how that could be causing the board to not send enough voltage to the inducer but i m wondering if maybe the capacitor breaking caused some feedback issue to the board that might have damaged it.
A quick test of your capacitor can tell you a lot.
All modern microprocessor controlled furnaces by manufacturers such as carrier include a self diagnostic procedure to test the function of the inducer motor.
If the unit will turn on but the blower motor is not turning on there are a couple of ways to check if the draft inducer motor has gone bad.
Or if it does it s going to be weak or start and stop repeatedly every 30 seconds or so.
The result is not enough juice makes it to the inducer motor and it most likely won t start up.
If the draft inducer does not start then you probably either have a thermostat thermostat wiring problem electrical problem control board problem or a bad draft inducer.
You have a blinking light on the control board that will tell you whats wrong or what to check first.
If your furnace blower motor hums when it s switched on but at the same time does not actually turn the capacitor may be damaged.