On 8/25/14, 10:49 PM, Jan Philips wrote:
I've had a problem with A/C at my parent's house, currently
unoccupied. We've had some temperatures over 95F and some power
outages from storms. The thermostat has a few-minute delay.

The thermostat was set on 78F. When I went over there late Friday
afternoon, the compressor was not running and it was 89F inside. I
cut off the curciut breakers and turned them back on to see if it
would reset it. After a few minutes, nothing had happened.

I checked the pan under the air handler and it was dry.

Then I saw that the batteries in the thermostat were low. I cut off
the unit at the thermostat and replaced the batteries. I turned it
back on, and in a few minutes it came on and started cooling.

This made me suspect the thermostat, but read on...

I went back Saturday afternoon and again the compressor was not
running and it was 90F inside. I cut the circuit breakers off and
back on and switched the thermostat to off and then back to cool. In
a few minutes it came on.

I went back Sunday and again today (Monday) and it is still working.

Any ideas of what the problem is/was? (At first I suspected the
thermostat, but now I don't know.)

Was the blower running? If neither the blower nor the compressor was
on, I'd get a volt meter and see if there was 24 VAC on the cooling
terminal of the board that controls the heat pump. I believe that's
usually the yellow wire.

I once had voltage at the thermostat end but not the control board end.
The wire had broken about 4 feet from the control board. I located
the break by moving the cable at various points, starting at the control
board.