On Mon, 05 Sep 2011 18:27:02 -0400, RBM wrote:

On 9/5/2011 5:45 PM, Tony Burbank wrote:
Outside unit just hums, dunno what tune.

Put a call in, service tech says it's the capacitor. I seen Back to the
Future, and not about to fall for a scam.

Could it be the thermostat or low on freezone?

If he made this determination in person, it sounds reasonable. If he
just speculated this over the phone, it is possibly something else. The
contactor in the condenser is powered (24 volts) from the thermostat and
many contactors hum when energized. The electricity to the condenser
motor, which works through the contactor, may be off, or otherwise
compromised.







A thousand things are possible - but of them, only one is probable.
Start with the capacitor, or hire someone to come in and make a
definitive diagnosis.Which will LIKELY be the capacitor.