I hear a humming noise coming from my outdoor activities unit. Everything seems to work fine. What could be causing this noise?

Answer

There are a lot of regular hums on an outdoor unit: the fan motor, the compressor, the electrical contactor, etc. There is a lot of air movement, and a fair amount of vibration from all these things.

Updated on April 9, 2018

Original Article:

How to Diagnose and Repair Your Air Conditioner (A/C) Capacitor
By Dan Robbins
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