AC randomly shuts off

Old 08-21-16, 01:20 PM
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AC randomly shuts off

I have an Armstrong air conditioning and heating unit that was built is 2007. The model number is Gtd80ct100d20cl-2a. The unit randomly shuts off on its own (usually during the peak of the hottest time of day) and then turns back on later in the day.

When the unit shuts off, the thermostat also shuts off. When the unit decides to turn back on, the thermostat also turns back on and everything functions properly as if nothing went wrong. The thermostat is not battery operated and I checked to see if it had recieved incoming power of 12 or 24 VDC (I can't remember how much at this moment) and it had no power supplied to it.

Next, I went outside to the breaker box to see if it had tripped (although that doesn't make sense, because it will randomly turn back on). It didnt.

Then, I opened up the panel to the Armstrong air unit to check whether it was receiving the right amount if incoming power from the breaker box and it does. I followed the incoming power line which eventually leads to a circuit board (Assuming it is the control board). The board is provided power and there is no power going out to the terminals to the thermostat. I assume there are no issues with any fuses since the system will turn itself back on later. Is the board overheating?

Any advice is greatly appreciated.
Old 08-21-16, 01:29 PM
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Welcome to the forums.

That's actually a common problem and as a guess I'd say you have a clogged condensate drain pan and a float switch is activating and shutting down your system.

Check your drain system. If the air handler is an attic.... check the overflow pan.

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