Most AC condensers have a time delay safety switch that won't allow you to turn it on immediately after it has shut off. It is usually a 5 minute delay.

The condenser could have a intermittent start up problem. The start capacitor in the condenser may need to be replaced.

Since you just bought the house, it would be a could idea to have a qualified HVAC tech inspect your equipment.

Thanks,

I cancelled the appointment and left this afternoon to come back and find it off and unresponsive again. Same time of day. Hmmmm.

There is no timer on the thermostat, but I played with it a bit - took the (2 AA) batteries out and put them back in. Although the LCD was working and showing a much higher indoor temp than the A/C was set to - this might be a case of bad batteries maybe? Worth a shot anyway.

No clue - but I would feel really dumb calling a tech out because of dead batteries so I'll swap them out and see!

This post was edited by karyn on Tue, Oct 15, 13 at 17:09

It doesn't hurt to change the batteries, but I suspect you have another problem.

Just a follow up with the solution -

There is a condenser drain line and an overflow switch that turns the system off if the water backs up.

The drain line was clogged so it was switching it off - they blew it out with gas and all is good! $45 total cost.

Maintenance tip - pour bleach or drain cleaner down the drain lines ever couple of months to keep the clear