April 15, 2021 Uncategorized

For the most part, your thermostat works flawlessly and allows your HVAC system to function as usual. But there are times when you try to change the setting, and yet it doesn’t seem to respond. When this happens, you may think that there is something seriously wrong with your furnace or air conditioner. But we recommend that before jumping to that conclusion, you try take a look into possible thermostat issues first. By having some basic thermostat troubleshooting skills, you may save yourself the cost of a service call or unnecessary stress.

Marsh Heating and Air Conditioning is your reliable HVAC company in Maple Grove MN. We are your experts in home comfort systems, including thermostats.

Thermostats for Beginners

A thermostat is a device that controls the temperature in an HVAC system. It allows you to set a preferred temperature and works to keep your room at your desired level. When your furnace or air conditioner reaches your set temperature, the thermostat will turn the system off to prevent it from overheating.

Here are some troubleshooting steps you can try when your thermostat does not seem to work properly.

No Power

It’s quite easy to determine when there’s something wrong with your thermostat. One of the indications is a dark display. When this happens, a lack of power can be the problem. Therefore, try to open the battery compartment and replace the batteries. Also, check the breaker and see if it tripped or find out if there’s a blown fuse. Reset the breaker as necessary.

If the thermostat still fails to respond, make sure the breaker is turned off and remove the covering. If it looks too dirty inside, clean it off with a soft brush or canned air and eliminate any dust buildup or grime that may be affecting its usefulness. It also helps to look for issues like wonky wiring or screws and tighten them up. If you discover any corrosion in the wiring, it may be best to replace the thermostat altogether.


Like computers and smartphones, simple rebooting can eliminate your thermostat’s problem. You can do this by turning your furnace or air conditioner off. Then, go to your breaker and turn off the power to your thermostat or HVAC system. If you haven’t labeled your breakers, test them now and label them correctly. Next, leave the breaker turned off for about 30 seconds to a minute then turn the power back on to your HVAC system. This should get your system back on. If it still not working properly, you should contact your trusted HVAC professional.

Thermostat Mode

Ensuring the thermostat is set to the proper mode may be a no-brainer, but sometimes, this simple step can be neglected and cause discomfort. If you want your HVAC system turned on, set it on “COOL” and if you need some warmth, set it to “HEAT.” Believe it or not, many people accidentally leave their thermostat on “OFF” while waiting for it to start up.


The positioning of the thermostat can also affect its performance. If the thermostat is placed in a bad position, it will not accurately control your home’s temperature, so be sure to check its location. Avoid exposing it to direct sunlight, other heat sources, or cold drafts. Most of the time, relocating the thermostat easily fixes this problem.

Also, try checking if the thermostat is balanced. Using a level device, make sure your unit is perfectly secure. If it isn’t, then, your mercury switch won’t work accurately.

Short Cycling

When a furnace or air conditioner turns itself on and off too frequently, it can be due to a malfunctioning thermostat. The term “short cycle” is a period when your HVAC system is running, and the shorter this cycle, the harder the unit needs to work.

If you have recently installed a new thermostat, it’s important to place it in a location where you can get an accurate temperature reading. As mentioned earlier, keep the thermostat away from direct sunlight or heat sources.

Sometimes, a broken thermostat can cause your HVAC unit to short cycle too often. If you suspect the thermostat is no longer in good condition, consider buying a new one.

Ask Marsh Heating and Air Conditioning

If these troubleshooting steps don’t seem to work and you need further assistance, do not hesitate to call Marsh Heating and Air Conditioning. We’d love to help you restore your comfort in no time. We are your trusted Plymouth heating and air conditioning company.