Thermostats are an integral part of any HVAC system. Their sensors detect the room or house temperature and depending the settings, signal the AC to start cooling or to turn off cooling (in cooling mode). However, if your thermostat is suddenly reading the wrong temperature, you should perform some inspections to know the cause of the problem. You can get help from AC repair services. However, if you can spare some time, you can try many checks and fixes yourself. Here you go.
Reasons Your AC Thermostat Is Reading The Wrong Temperature
If you already know that your thermostat is wrong you should read the causes below. However, if you don’t, determining that is easy. Simply place a thermometer near the thermostat and after 15 minutes, check the temperature on it. If it matches, the thermostat is fine, but if it doesn’t, there is a problem.
Wrong Thermostat Location
The most common reason of your thermostat not reaching the set temperature or reading temperature incorrectly is the wrong location of the thermostat. The location of the thermostat is a critical factor in determining its performance. So, the location should be chosen carefully. It’s mostly the job of the HVAC installer.
If the thermostat is near vents, it will be too near the airflow. This will make it react more quickly to the cooling. The thermostat will signal the AC to turn off much before the whole house will reach the set temperature. You will notice insufficient cooling and may think that the air conditioner is malfunctioning when the issue would be the location of the thermostat.
Similarly, you should also check if the thermostat is near any heat source like an appliance or windows or a door that allows sunlight or heat into the house. If it is, then you should contact an expert for changing the location of the thermostat.
The right location for an air conditioner thermostat is the central part of your home. It should a room that you commonly use that doesn’t have the factors we have mentioned above. However, never install a thermostat in a narrow, empty hallway as low airflow there will lead to incorrect temperature readings.
Moreover, if you have two-story house, the right place the thermostat is the first floor. This is because the second story is usually slightly hotter due to the phenomenon that hot air rises and cool air sinks.
Dust On The Thermostat Casing And The Sensor
The sensor in the thermostat detects the temperature. If it’s covered with dust due to lack of cleaning, then it may not perform its job properly. So, upon noticing wrong readings of the thermostat, cleaning the device is a good start.
For programmable and mechanical thermostat, you may or may not be able to remove the cover without removing it from the wall. Refer to the user manual for instructions.
After removing the cover, gently cleanly the delicate components inside the thermostat and then put the cover back on.
In case you have a smart thermostat, you don’t need to remove the cover. Just make sure to clean the casing you’re seeing
The Thermostat Needs Calibration
If you have already done the thermometer test with the thermostat and seeing a difference, a cause of this difference could be calibration loss. Over time, thermostat lose calibration and show a few degrees lower or higher than the actual temperature which directly impacts the effectives and efficiency of your HVAC system. Calibration loss can be due to power outages, accidently bumping the thermostat, and dust buildup. It can also be due to no recalibration done in a long time.
Usually, you should check the thermostat for calibration (by using a thermometer) once or twice a year. But if you’re reading this, your thermostat is already showing wrong temperatures so a calibration may be due.
As there are many types and models of thermostats, the exact method varies so you should read the user manual or visit the thermostat manufacturer’s website to find the calibration instructions for the thermostat model you have. In case you need help, call in an expert.
Your Mechanical Thermostat Isn’t Level
This isn’t a concern for any modern thermostat that uses electrical sensors, but people who have a mechanical thermostat in their homes, should make sure that it’s level.
A mechanical thermostat’s leveling is an important factor impacting its performance. This is because they use mercury or a magnetic switch. They work perfectly only when they are perfectly level. If they are not, their temperature reading will be off the actual temperature.
Have an expert check your mechanical thermostat or switch to a programmable or a smart thermostat.
Poor Installation
We have mentioned the location issue earlier which is a part of poor installation. However, another factor in a thermostat installation is correct wiring. If done wrong, the thermostat might show wrong readings. Mostly, DIY thermostat installations lead to this problem.
Installation problems can be detected easily because the thermostat might start showing problems from the first day or within a few days of installation. Therefore, consult an expert who can check the thermostat wiring and fix it if that’s the issue.
Drained Batteries
Thermostats run on batteries and when they drain, the thermostat will act weirdly. The screen might fade or flicker and the temperature readings may suffer. So, when any problem with the thermostat shows up, you must check its batteries because sometimes, the issue is as simple as just replacing the batteries and calling it a day. Follow the user manual for the correct procedure of batteries replacement.
Faulty Temperature Sensor Of The Thermostat
A thermostat has a temperature sensor that does the job of determining the temperature. Commonly, dust can block the sensor and cause it to give incorrect readings, but if you have cleaned the thermostat and have gone through the above list of causes and the issue is still there, the it may be a faulty temperature sensor.
Temperature sensors are difficult to repair. So, when this component of a thermostat malfunctions, it’s time to buy a new thermostat.
Old Thermostat
This ties in with the previous point but without using the technical term: temperature sensor. Thermostats should be replaced after 10 years. So, a thermostat that is older than 10 years, will commonly malfunction, forget settings, won’t reach the set temperature, and detect incorrect temperature. Therefore, the best solution is a replacement.
Other Things That Can Impact The Temperature Readings Of A Thermostat
There are also other factors that can lead to incorrect temperature readings by the thermostat.
Clogged Air Filters
When air filters become clogged, it impacts the airflow. This problem already put stress on the AC, but also makes it harder for the thermostat to detect the temperature. So, clean the air filters regularly.
Check The Thermostat Settings
Sometimes, we change the temperature settings and forget it. So, check the settings and make sure they are correct.
Conclusion
Many things can cause your thermostat to show incorrect temperature readings. The most common ones are drained batteries, wrong thermostat location, dust on the thermostat, etc. So, you should go though the causes one by one. However, the best way of fixing any HVAC issues is to get help from air conditioner repair services McLean.
