# Carrier Model 58MXA banging/clicking noise on start up



## gsevans (Nov 20, 2006)

A banging/clicking noise occurs when my Carrier model 58MXA starts up. it does this for several seconds before it starts. It is a dual heat pump/gass backup system that switches to gas around 40degF

As each banging noise occurs the inducer motor attempts to turn and a click is also audible. The system finally starts but it seems to be getting worse.

Can anyone diagnose?


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## rakes9720 (Feb 10, 2005)

Maybe the inducer blower wheel is loose or damaged. You would have to remove the motor and inducer housing though. Don't do this unless you know what you are doing.

Or, try spinning the little fan on the inducer motor first and see if it turns freely. If not, your problem is most likely the motor or blower wheel.


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## gsevans (Nov 20, 2006)

Thanks for the post,
I tried that when the clicking/banging occurs I can freely spin the little fan on the inducer motor with no problems. It almost sounds like it is being electrically controlled ????

It dosen't happen all the time.


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## rakes9720 (Feb 10, 2005)

It still could be the motor itself, and maybe the electrical connection is bad somewhere, or the control board.


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## gsevans (Nov 20, 2006)

I tracked down the banging part of the noise to the reversing solenoid on the outside heat pump unit. Seems it was switching on and off and the noise was being transmitted thru the lines. 

I replaced the defrost timer on the outside unit with an old one that I thought was broken and not it works.

Any one else have problems with Carrier reversing solenoids switching from heating to cooling every few seconds???


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## #CARRIERMAN (Jan 4, 2007)

Hi gsevans

I am almost sure that your problem will return. What you are describing is the symptoms of a bad defrost terminator. I will almost bet you end up having to replace the defrost terminator.

Good luck
Rusty


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