5 Ways to Troubleshoot Your AC & Furnace Thermostat

If your air conditioner or furnace isn’t working properly, the issue could be with the thermostat. Before scheduling a service call, there are several ways you can troubleshoot the problem to determine if this is the case, and even resolve it on your own. Of course, if you need assistance in Colorado or Wyoming, Rheem Pro Partner is always available to answer your questions and provide help.

1. Check the batteries

Electronic thermostats are generally very reliable, so the issue could be as simple as old batteries. Replace the batteries when the low-power light comes on and this may well get your system functioning properly again.

2. Check for loose wires

Wires can come loose or not have a proper connection. Turn off the power and carefully remove the thermostat cover to check the connections. Tighten any loose screw terminals. If a wire is loose, place it back on the terminal clamp and tighten the screw.

3. Check for dirty components

Dust and dirt can get inside the thermostat and cause it to malfunction. With the power off, remove the thermostat cover and gently clean the components, especially the bimetallic coil and the switch contact surfaces. Dust inside with a soft brush. Clean the contacts by rubbing a slip of paper between them.

4. Check the anticipator

In mechanical thermostats, the anticipator controls how often the furnace or air conditioner cycles on and off. If yours is cycling too frequently or not frequently enough, the anticipator — a flat metal pointer on a disc — could be in need of a slight adjustment. Remove the cover and move the pointer one calibration mark closer to the word “longer” on the disc if the cycle is too frequent, or one calibration mark away from the word “longer” if it isn’t cycling often enough. In a few hours, you will know if the problem has been resolved.

5. Check the circuit breaker/fuse

The thermostat may have lost power due to a flipped circuit breaker or blown fuse. Test the circuit breaker or replace the fuse to resolve the problem. If this happens repeatedly, call your HVAC professional to see if there is a bigger problem causing the overload.

In Colorado and Wyoming, contact a Rheem Pro Partner for all your air conditioner and furnace needs! We’re happy to answer your questions.