Hum but no fan - http://www.hvacmechanic.com/ Forums
Original message
| grampamoses
 |  "Hum but no fan"
, posted Mon 30 Jun 00:53  
Hi
I have a lennox G24M3/4-120A-4 furnace. Havent used it for about 3 months, but today went to turn on the A/C. Turned on Thermostat, nothing happened. When I turn on the AC or if I turned just the fan on, I can hear a click, then a hum. I turned off the power opened it and spun the fan. Spun freely. Turned on again and still nothing but a hum.
The motor was replaced early last winter, so I dont think it is the motor.
Suggestions please.
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Replies:
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| Houston204
| "Re(1):Hum but no fan" , posted Mon 30 Jun 08:15
Capacitor
"Tip of the Day" Remember to remove power first.
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| | grampamoses
| "Re(2):Hum but no fan" , posted Mon 30 Jun 20:11
Thank you.
I replaced the capcitor, and that DID correct the problem. The fan comes on now. Thank you very much!! HOWEVER, the AC still does not work. Set the thermostat for cool, the furnace fan comes on like it should now, but the fan unit outside does not come on at all.
I checked all the wiring at the furnace board to make sure I didnt disconnect anything when I changed the capacitor, but looks ok. Any ideas what to check?
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| | yuri
| "Re(3):Hum but no fan" , posted Mon 30 Jun 20:28
Circuit breakers inside and sometimes in box outside. Low voltage wiring outside for damage by wheedwhacker, rodents.
Yuri
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| | Houston204
| "Re(4):Hum but no fan" , posted Mon 30 Jun 22:03
The compressor gets hot and will drop out on thermal protection when the condenser fan motor does not run.
Remove power and run a water hose over the compressor to cool it. If you have an insulating blanket oer the compressor you will need to remove it first. (Or just turn it off and wait 4 to 6 hours).
"Tip of the Day" Remember to remove power first.
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| | grampamoses
| "Re(5):Hum but no fan" , posted Wed 2 Jul 01:56
The compressor outside does not come on either. When set to cool the only thing that comes on is the blower fan in the furncace.
I had a new electrical panel put in last month. Perhaps they did not connect the power back up right.
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| | theduke03
| "Re(6):Hum but no fan" , posted Wed 2 Jul 18:34
I had this one just 4 days ago. A customer had a subpanel added by some hacker electrician. Not only did the sparky use the wrong breakers, he also stuffed breakers into slots that had no connections to anything. If you have a meter go to outside unit and open the disconnect box. Check for 230Vac from L1 to L2.(not from each line to ground like most homeowners would)!
"My dad was the most feared furnace fighter in Northern Indiana."
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