New Homeowner (December) and I need help troubleshooting. Everything was peachy keen until I returned from a week vacation. A/C will not cool, but fan will turn on if I take it off of auto. "Wait" is indicated on my thermostat and I've 'waited' all night.

High level troubleshooting completed: 1. Resetting A/C Schedule and setting to schedule 2. Setting temporary temperature to 76 with System>Cool 3. Followed troubleshooting instructions for "Wait" indicator/non-responsive.
4. Replaced batteries in thermostat


While I was gone, I had a permanent hold set at 78cool/68heat. I live in Florida and this time of year that should have been pretty close to turning it off.

Thermostat model: Honeywell RTH7400

The owner's manual suggested I set the heater setting to above the current temp (80 degrees F) and the cool setting to below that temp and wait 5 minutes for the system to reset. No avail, but here are the details of that fruitless effort:

-I did this by System>Heat>used up arrows to scroll to 81. What's strange is that once I get above the current temp it starts saying cool under the number as I scroll, as though cooling is the setting it thinks will raise the temp. It does the opposite when I set System>Cool>down arrow to lower temp to 76 (Heat shows up under the scrolling temp as I bring below current temp).

Sounds: -Fan turns on only when I manually set it to 'on.' Does not blow cool air or hot air. -After following the 'wait' instructions, I hear a click, maybe a quick double click, but the fan will not turn on when set to auto. enter image description hereenter image description here

  • 1
    Have you power-cycled the equipment? Sometimes a simple reboot fixes things. Look for a switch near your furnace, or use the circuit breaker. Leave it off for 10 seconds. – isherwood Mar 23 '17 at 16:50
  • Yeah, same story. – l c couter Mar 23 '17 at 21:13
  • Can you take a photo of the wiring going into your thermostat's base? – ThreePhaseEel Mar 23 '17 at 22:17
  • Sorry for the delay. @ThreePhaseEel I've uploaded the pic. This is one of 3 weekends in Florida that it's actually not awful for it to be broken. – l c couter Mar 26 '17 at 18:51

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.