Is Your AC Thermostat Broken? Find Out

A thermostat detects temperature fluctuations and allows you to adjust the temperatures to the desired setpoint. However, a malfunctioning thermostat will result in erratic cooling operations, whereby the AC runs non-stop for extended periods. In addition, your house might get extremely cold as the thermostat won't generate electrical signals when the temperatures fall below the preferred value. When your thermostat stops working as expected, call an AC repair technician to inspect and fix it, ensuring effective indoor climate control. Below are the signs indicating a broken thermostat.

AC Won't Turn On

The thermostat could be faulty if your cooling system does not turn on. Since the AC runs according to the signals that the thermostat transmits, worn out and loose wiring may cause a lack of communication between the AC and the thermostat. This results in no response from the AC when you adjust the thermostat settings. In this case, your AC repair technician will repair the thermostat wiring for clear transmission of signals. If the thermostat is aging, they may suggest a replacement.

Irresponsive Thermostat Commands

Typically, the thermostat should respond instantly when you adjust the temperature setting. So, your thermostat could be defective if you engage a particular setting but fail to receive a response within a few minutes. In addition, your thermostat should detect overly low temperatures and cut off the cooling cycles. Failure to do so could be due to the accumulation of dirt, dust, and debris in the thermostat control board that compromise the electrical components, causing its inactivity. Therefore, you should contact an AC repair contractor to clear the thermostat housing of dust and debris for proper functioning.


If the thermostat is faulty, it will cause your unit to short cycle. This is because the thermostat sensor detects the temperatures erroneously, leading to frequently running premature cooling cycles. As a result, the AC cannot achieve the programmed setting, causing uncomfortable and inconsistent temperatures across your premise. Additionally, the start-up and shutdown processes consume a lot of electricity while wearing out the components much faster. 

Thermostat Does Not Correspond to Room Temperature

Despite opening the air registers, you may notice some spots in your house are cooler than others. This is because the thermostat sensor cannot accurately measure indoor temperatures, causing temperature variations throughout your home. Besides room-to-room temperature difference, a broken thermostat will not attain the display temperature, bringing a sultry indoor environment. In this case, your AC repairer might need to replace the thermostat or reposition it in an area free of constant temperature fluctuation.

A broken thermostat will cause an uncomfortable and uninviting ambience. Therefore, call an air conditioning repair technician if you notice the abovementioned issues. Most importantly, invest in routine maintenance to ensure the cooling unit components are always in excellent condition.