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.)

Hi,
Is it programmable 'stat? Can you tell the model?
If program is still as programmed, did you check?
If not sure, you can reprogram it or set to default program setting.
If battery low was displayed from that time battery is good
another couple weeks B4 it really goes dead.