The HUMMING Goodman
#1
12-04-15, 08:59 AM
The HUMMING Goodman
Hello,
What's going on with the unit I have is when the blower quits blowing air through the ducts I still here a noticeable hum coming through the ducts like something is not shutting down completely. It keeps humming until the blower kicks back on. The hum never stops. I'm good with fixing it, problem I have is trouble shooting. Im not sure if its a fan switch or something to do with the thermostat. I do not know the age of the unit as it was it the house when I bought it. I will provide any additional info that is required. Thanks for assisting me, my children and wallet, we greatly appreciate.
What's going on with the unit I have is when the blower quits blowing air through the ducts I still here a noticeable hum coming through the ducts like something is not shutting down completely. It keeps humming until the blower kicks back on. The hum never stops. I'm good with fixing it, problem I have is trouble shooting. Im not sure if its a fan switch or something to do with the thermostat. I do not know the age of the unit as it was it the house when I bought it. I will provide any additional info that is required. Thanks for assisting me, my children and wallet, we greatly appreciate.
#2
12-04-15, 09:22 AM
Group Moderator
Welcome to the forums.
I couldn't begin to imagine what is humming. There is a 24vac transformer that runs the equipment. They have been known to hum but not usually loud enough to be heard upstairs.
You said you hear the hum after the blower shuts off.... that doesn't leave to much. You'll need to listen at the furnace and try to locate the source of the sound from there.
I couldn't begin to imagine what is humming. There is a 24vac transformer that runs the equipment. They have been known to hum but not usually loud enough to be heard upstairs.
You said you hear the hum after the blower shuts off.... that doesn't leave to much. You'll need to listen at the furnace and try to locate the source of the sound from there.
#3
12-04-15, 09:52 AM
Thanks. I spent the last 20 min downstairs and this is what I saw; when the blower shut off I watched the fan come to a complete stop and then go full speed in the opposite direction. To me thats not normal operation but I do not know whats causing that. Could it be a bad "cap" on the motor?
#4
12-04-15, 09:54 AM
Group Moderator
That would be a first.
If this is a furnace.... remove the burner access door, look on side wall for ID plate and post the full model number.
If this is a furnace.... remove the burner access door, look on side wall for ID plate and post the full model number.
#8
12-04-15, 05:43 PM
Group Moderator
In looking at the schematic.... the blower motor is a multiple speed 120v PSC motor. There is nothing in the furnace that could make that motor run backwards.
Do you have a multimeter ?
Do you have a multimeter ?
#10
12-05-15, 09:29 AM
Group Moderator
Before you do anything.... confirm this is the right wiring diagram for your unit. There should be a match to it posted on your unit. I originally thought your blower motor was 120v but I see it may be 240v as it's part of an electric heating system.
Your motor should use purple as L1 and red or black depending on speed selected. Check from the purple to the other blower wires and see if there is any voltage when the fan should not be running.
Click on diagram for larger view.
Your motor should use purple as L1 and red or black depending on speed selected. Check from the purple to the other blower wires and see if there is any voltage when the fan should not be running.
Click on diagram for larger view.
#11
12-06-15, 07:49 AM
It's a 240 motor and I'm getting 20v across common(purple) to hot (red/blk) when the fan is suppose to be off. Another note is that when only the common is connected the fan still runs. 15mf cap reads good as well.
Is there a setting on the forum to receive notifications when a reply is posted.
Is there a setting on the forum to receive notifications when a reply is posted.
Last edited by PJmax; 12-06-15 at 09:31 AM. Reason: activated email notification
#12
12-06-15, 09:30 AM
Group Moderator
Use the "Go Advanced" reply screen. At the bottom of that page you'll see "click here to subscribe to this thread". Then use drop down box to select "instantly by email".
I activated it for you. You can also turn it off if wanted.
I'll check further into the blower issue.
I activated it for you. You can also turn it off if wanted.
I'll check further into the blower issue.
