Ask Experts Questions for FREE Help !
Ask
    K844671's Avatar
    K844671 Posts: 1, Reputation: 1
    New Member
    		  
    #1

    Mar 18, 2012, 08:14 AM
    AC unit hums while off
    AC is off and a hum can be heard coming from the unit outside. Should I be concerned?
    Stratmando's Avatar
    Stratmando Posts: 11,188, Reputation: 508
    Uber Member
    		  
    #2

    Mar 18, 2012, 08:29 AM
    The Contactor may hum when unit is operating, but you wouldn't hear it due to the Fan and Compressor running, I have seen units that break 1 leg of the 240 volts and the compressor has a constant hotleg.
    If you can do safely, see if you have a 1 or 2 pole contactor outside. If 2 pole, all power should be removed from Compressor and Fan.
    Do Fan and Compressor appear to work correctly, Spinning and cooling?
    thermalmedics's Avatar
    thermalmedics Posts: 153, Reputation: 13
    Junior Member
    		  
    #3

    Mar 18, 2012, 09:30 AM
    I have heard transformers hum from the street below the rooftop unit. Almost like walking under a high voltage power line.
Not your question? Ask your question View similar questions
 

Question Tools Search this Question
Search this Question:

Advanced Search

Add your answer here.


Check out some similar questions!

Central AC Unit Hums [ 2 Answers ]

In my attempt to repair my central AC unit, what could possibly be the issue if the central AC unit does not run and all I hear from the outside central AC unit is a "humming" sound? I replaced the fan motor because when I first heard the "humming" sound coming from the outside AC unit I noticed...

Goodman cpke30-18 outside unit does not work, hums [ 2 Answers ]

I have a goodman split unit modell number on the outside unit is CPKE30-18. Had this when I moved 5 years ago. Have read most negative reviews on this equipment. The outside unit has stopped working, I do hear an electrical hum at the outside, the fan does not rotate and I have no money to...

Trane Heater Blower Unit constantly hums [ 3 Answers ]

I have two (2) Trane gas heater/blowers in my basement and one is completely silent when the blower isn't on and the other has hummed constantly for 10 years unless you turn the power completely off. I had some work done on my hot water heater and the plumber asked me why the blower unit was...

The fan on my central ac unit hums and won't turn on [ 1 Answers ]

The fan motor gets very hot to the touch and the fan will not rotate

Outdoor A/C unit hums but doesn't come on [ 2 Answers ]

I have a 2 ton century A/C unit. The outside unit will not come on, but it hums. I have determined the following: The air handler fan in the inside unit comes on. The compressor and the fan in the outdoor unit do not come on, but it hums. (I assume the compressor is not coming on... lines are...

View more questions Search