Quality service since 1998

Solid Signs That Your Thermostat is Broken

How to tell if a thermostat is bad is one of the commonly searched topics by homeowners with furnaces, and rightfully so. The role of the thermostat in a home is crucial because it allows easy control of the in-house temperatures, regardless of the weather outside. The first sign that the thermostat is no longer working is a lack of cool or hot air, regardless of how much you try to adjust it. It is important to note that sometimes the problem could be with the furnace and not the thermostat, which is why these signs are essential.

Room temperature not changing

A direct energy thermostat not working despite being turned on is another problem that can quickly get out of hand. It may be hard to notice this if you rarely adjust the unit, but paying attention to the room temperature when the air conditioning unit seems to be working fine can help you identify the issue.

The 15-minute 5-degree test can also be helpful. Reduce the thermostat by 5 degrees and wait 15 minutes. If the air from the vent does not change, expert help will be necessary. Either the thermostat or heating system could be broken.

Not turning on

A thermostat that does not turn on will remain blank or black, but this problem is common with digital thermostats only. A professional inspection of the unit will determine the problem and show whether it can be replaced or repaired.

Difference between the room temperature and thermostat reading

Sometimes the air conditioner and the thermostat could be operating, but the temperature in the room differs from the one on the unit. You can use a room thermometer to show the difference in temperatures.

Although this is usually an indication of a thermostat problem, the change could be because the unit is mounted at the wrong place in the house. For example, if  placed just above the stove, it will read higher temperatures than the actual temperature in the room. On the other hand, if it is too high, the unit will not signal the furnace to turn on.

Causes of thermostat problems


Dirt, dust, and other debris are not good for the thermostat and air conditioner functionality. These elements can interfere with the mechanical aspects of the units, thus causing them to malfunction.

The remedy is  first to determine if they are the actual cause by uncovering the thermostat after turning it off. A small brush, a dry piece of cloth, or compressed air can all be used to clean the unit, but water should never come in contact with the appliances.

Power supply issues

One of the first steps to figuring out how to fix a broken thermostat is determining a sufficient power supply, especially if it is not turning on or communicating with the air conditioner. Some factors to consider include:

Failing batteries: Thermostats use batteries that need to be changed regularly; otherwise, they start to malfunction before the warning pops up. A fresh set of batteries might  be the solution to the problem.

Wiring issue: Another step in how to know if your thermostat is bad is checking the wiring. Corroded, loose, and defective wires can also cause the thermostat to fail. The switches on the AC and thermostat units can also cause the same problem.

Flipped breaker: Only wired thermostats can have this problem because they have a wired electrical panel. Check the panel and flip the one for the thermostat. It should be labelled.

If everything seems to be in place, but the thermostat is still not working as it should call Air Makers. The professionals will do an inspection and determine the root cause of the problem.

Problematic anticipator

Modern thermostat models don’t have anticipators, which means that this problem can only occur in older models. It is a metal tab that is under the unit cover. It has a longer and shorter cycle that is labelled, and you can adjust it accordingly.

This solution may provide reprieve, but it is not permanent. Professional maintenance routines can prevent the problem and provide long-lasting solutions.

Longevity of the thermostat

Every thermostat has a lifespan that, when it nears, it starts exhibiting problems. The average longevity is  ten years, which means that if it has served you for that duration or close, replacing it will be better than repairing.

Steps to knowing if the thermostat is working

The following tips are the answers to the question, “how do I know if my thermostat is broken”? They can help uncover the real problem and provide permanent solutions.

Check if the thermostat is ON and confirm that it is cooling or heating the air as it should. The settings will indicate whether it is supposed to be heating or cooling without any delays in execution, especially if it is a programmable one.

Increasing the temperature gradually and waiting to see a different outcome is another great troubleshooting option. Both the furnace and thermostat should make clicking sounds when it is being adjusted, failure of which indicates that the two are not communicating as they should.

Another sign to look for is how the furnace turns on and off. If it is inconsistent, there could be several reasons, including being dirty or installed in the wrong  location.

Inspecting the breaker and increasing the temperature while professionals are checking out the air conditioner can also help save a lot of money and keep the appliances working perfectly for longer. While checking the breaker, look at the wiring, and report or fix any that seems loose or out of place.


If you suspect that your thermostat is not performing as well as it used to, or you’re unsure whether it is the HVAC unit that is damaged, call Air Makers. You will get impressive services that will restore your units to their original efficient state. You can always buy a new thermostat if the current one is exhibiting a lot of problems that are proving to be too costly to fix.

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