The first thing that is supposed to start when a furnace starts up is the draft inducer.
Carrier furnace inducer motor not running.
Applied 110 v to inducer motor worked.
First make sure that power is getting to the motor.
A bad furnace inducer motor can result in a loud buzzing or whining noise and loss of heat.
Ran ohm meter on limit switches all open meter.
A failing inducer motor may create a noise shortly after a heating cycle begins.
Shows no power from circuit board for high speed post for inducer motor and not from low speed post.
This could be a tapping noise or a humming or whirring sound.
Sometimes the bad inducer motor becomes very hot to the touch.
If the blower motor is burned out replace it.
If power is getting to the blower motor but the motor does not run the motor may be burned out.
Jumped lower pressure switch.
Our forced air units can keep your home warm with models that automatically adjust as conditions change circulating warm air nearly continuously for high efficiency quiet operation and consistently comfortable temperatures.
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.
Backed by the intelligent infinity control and a variable speed blower this two stage furnace will run in low stage up to 90 of the time.
If the blower motor hums check the blower fan to ensure that it spins freely.
Longer low stage run times give you better energy efficiency better temperature control and increased comfort.
No power to the inducer motor from the circuit board checked limit switches all are open.
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.
If i use a fiberglass filter it whines when the furnace is running at high speed but not at low speed.