A thermostat that keeps resetting usually points to an issue with low voltage, a system fault, or a software schedule. The primary culprits are dead batteries, a dirty air filter causing the furnace to overheat, or loose wiring.
A common reason your thermostat may be resetting itself is if your home is having power issues. Check and replace the batteries if applicable. Look for loose or damaged wiring, but don't touch it. Ensure the power supply to the thermostat and your HVAC system is stable.
To fix a thermostat that isn’t holding or reaching your desired temperature, immediately check for a dirty air filter, blocked or closed room vents, and accidental schedule overrides. Make sure the thermostat is set to "Hold" or "Permanent Hold" rather than "Run Schedule".
A failing thermostat can compromise your comfort and spike your utility bills. Watch for these top warning signs:
Setting your thermostat at a consistent temperature can also help prevent short cycling. Avoid adjusting the temperature drastically or frequently, as this can cause your furnace to cycle more frequently. Instead, aim for a comfortable temperature and leave it at that setting to minimize unnecessary on-off cycles.
To make your thermostat stay at one temperature, activate the "Hold" or "Permanent Hold" feature. This overrides any pre-set daily schedules.
Average Lifespan of a Thermostat
With a straightforward design and basic scheduling features, they are reliable workhorses that can last 10 to 15 years with proper care. Routine programming updates and occasional recalibrations go a long way toward keeping them accurate and extending their usefulness.
How can you tell if a thermostat is bad?
Replacement of thermostat unit
Upgrading to a new thermostat (unit + installation) typically runs $140 to $350, depending on model and complexity. There is also a broader range—$80 to $440—with variations based on location and type of thermostat.
A standard thermostat usually allows the temperature to drop 1 to 2 degrees below the set point before kicking the furnace on. This built-in delay, known as a "temperature swing" or "hysteresis," prevents the system from constantly turning on and off.
5 Warning Signs It's Time for Furnace Replacement
When your thermostat is set to 73°F but reads 78°F, your system is struggling to keep up with the heat or is misreading the ambient air. To get your home back to a comfortable temperature, you can easily troubleshoot a few common culprits.
Common causes include dirty filters, airflow problems, thermostat placement issues, high heat load (especially in Florida), and HVAC system performance problems. Sometimes the thermostat is calling correctly, but the system cannot cool or heat the home fast enough to reach the target.
While a furnace can technically operate without a thermostat, attempting to bypass the thermostat manually is dangerous and not recommended for several reasons:
In some rare cases, a malfunctioning thermostat can cause the heating system to overheat, posing a fire hazard. This risk is higher in older systems or those without up-to-date safety features. Regular TLC can help identify these risks early, reducing the chance of fire-related incidents and keeping your home safe.
Disconnect the old thermostat and unscrew the mounting plate. Check the new thermostat instructions for compatibility and wiring guidance. Connect the labeled wires to the new thermostat. Attach the new mounting plate to the wall.
Yes, 72°F is a very comfortable temperature for your daytime heat setting. However, it is slightly higher than the recommended energy-saving guidelines, which could increase your heating bill.
A plumber isn't usually needed for thermostat replacement unless your thermostat directly controls a water-based heating system, such as underfloor heating or a boiler with complex plumbing connections. Even then, an electrician is typically the right professional to handle the wiring.
Many homeowners are curious whether they need an electrician to replace a thermostat or if they can install a home thermostat on their own. While some try the DIY route, professional thermostat installation is usually the smarter, safer choice—especially with the range of high-tech models available today.
The cheapest temperature to keep your house in winter is 68°F (20∘C20 raised to the composed with power C𝟐𝟎∘𝐂) while you are home, and lowering it to 61°F–65°F when you are away or sleeping, according to the Department of Energy. Setting your thermostat back 7°–10°F for 8 hours can save up to 10% a year on heating costs.
To stop your thermostat from changing temperatures on its own, you generally need to disable its automatic scheduling or activate a "hold" setting.