One of the most common reasons for a thermostat to reset itself is old batteries. If you haven't changed them recently, replacing them with new batteries is a good first step.
Solution: Switch out your batteries. It can be as simple as switching out the batteries on your thermostat device. This could also be the reason your screen can go blank sometimes. Thankfully, most thermostats should tell you when the time comes to replace them.
If you have a programmable thermostat, you need to look for the 'hold' button. Manually turn the temperature up, or down to the desired setting, then press the 'Hold' button once. The word 'hold', or 'permanent hold', or something similar should appear on the digital thermostat.
A bad thermostat can be detected when your AC or furnace is not turning on, your HVAC systems are not turning off, the thermostat not responding, your HVAC system is short-cycling, the room temperature not matching the temperature displayed on the thermostat, and the programmed setting resetting themselves.
Some of the most common thermostat issues include:
The thermostat is broken, not properly level, or dusty. The thermostat needs to be recalibrated. There is loose wiring causing a thermostat issue.
This is where the “Hold” button on your thermostat comes into play. By pressing “Hold”, your thermostat will lock in the temperature it's currently at until you change it again. When you are ready for your normal schedule to resume, simply press the “Run” button and return to your typical programming.
If the temperature is set to 74°F but the thermometer shows 78°F, you will have to recalibrate the thermostat to account for this 4-degree deviation. Even with older AC units or furnaces, you might have to recalibrate your thermostat from time to time.
The Lifespan of a Thermostat
On average, most thermostats last about 10 years, depending on the model, usage, and proper maintenance. However, many people decide to replace their unit sooner to take advantage of new energy-saving technologies.
Thermostat battles—If your thermostat keeps dropping to 62 degrees after you've bumped it up to a cozy 70, it might not be the thermostat. With app-based controls, other family members may adjust or turn off your temporary hold. Find out who else can access the thermostat app, or consider changing the account password.
Your house and attic insulation can wear down over time. Your house also may have hidden attics that aren't properly insulated or uninsulated garage walls that are attached to your home, and this can cause problems with heat escape, unwanted airflow, and drafts. Your ductwork has problems.
The only reason it may change by itself is you have a programmable thermostat that has a schedule running on it. Either that or someone is moving it without your permission. Assuming it's the first, try locating the “hold” button.
Certain situations may require you to reset your thermostat. For instance, if it's cold outside, and you're cranking up the temperature for your furnace but the house still doesn't feel like it's warming up, you may need to reset your thermostat.
Once you set your thermostat (the main interface between you and your HVAC system), you likely assume it's guiding your heating system to warm your home to the set temperature. It may not be. Thermostats can lose calibration over time from being accidentally bumped or from dirt accumulating.
Yes, many smart thermostats are designed for DIY installation, and manufacturers typically provide step-by-step guides and videos. However, if your HVAC system is older or lacks proper wiring (like a C-wire), the installation might become more complex, and you may need professional help.
In the heating, ventilation, and air conditioning (HVAC) business, short cycling is a phrase used to describe when a heater or air conditioner cycles on and off too frequently. It signifies a problem in your heating system's proper functioning and efficiency, in which it is not completing its heating processes.
In most cases, installing a new thermostat is a relatively simple do-it-yourself project that can result in improved comfort and convenience and one that can help you save energy.
High temperature readings
The main symptoms of a failing thermostat are related to engine overheating. It can be easily noticed because the temperature gauge in the vehicle will probably read unusually high. This can be caused by the valves being stuck in a closed position.
Weak or Old Batteries
One of the most common reasons for a thermostat to reset itself is old batteries. If you haven't changed them recently, replacing them with new batteries is a good first step. Weak batteries can't maintain the necessary power to keep your thermostat running properly, leading to resetting issues.
For many of us, 70 degrees is the ideal indoor temperature, but when it is close to 100 degrees outside, your AC unit will be working quite hard to meet these expectations. Consider setting your thermostat at 75 degrees to 80 degrees in your home if the outside temperature is approaching triple digits.
Clean the Thermostat
Sometimes, when the room temperature doesn't match the thermostat setting, the problem could be dirt buildup on its interior parts. A dirt coating around the inner components may create excess heat and cause the thermostat to give the wrong readings.
Another problem that can cause your house to be hotter than what you've set the thermostat to is if your home's HVAC system isn't sized properly. An HVAC system that's too large for your house will cool your home unevenly. It will only cool some rooms off and then shut off versus cooling down the entire house.