How to Tell If Your Thermostat Is Bad

The center of central control for your home’s heating, ventilation, and air conditioning (HVAC) system is the thermostat. When it runs as it should, it effectively controls the temperature to provide a pleasant interior environment. When it breaks down, however, you may experience pain, expensive energy bills, and even damage to your HVAC system. Many people believe the HVAC equipment is responsible for the improper heating or cooling of their house. Although it sometimes is the case, a malfunctioning thermostat is usually the true offender. Early identification and resolution of thermostat problems can help you avoid needless utility bill expenses and repairs. How to Tell If Your Thermostat Is Bad? This in-depth article will go over the many indicators of a malfunctioning thermostat, how to test it, and what actions you could take to either repair or replace one.

1. The thermostat runs without power.

Among the most clear indicators of malfunction is a thermostat that won’t switch on. Usually indicating one of the following, a blank or unresponsive display leads to

Should your thermostat operate on batteries, your initial action should be to replace them. Usually every 6 to 12 months, most thermostats need fresh batteries.
A power surge might cause a breaker to trip, therefore depriving the thermostat of its supply. See your electrical panel; if needed, reset the breaker.
Wiring connections may becoming loose or rusted over time. Remove the thermostat cover and look over the wiring for any obvious problems if you are comfortable doing so. See an HVAC technician for repairs if the wiring seems broken.
Should none of the following actions restore electricity, your thermostat might be beyond repair and call for replacement.

2. The HVAC System Never Turns On

Your thermostat signals the HVAC system to switch on when temperatures fall or climb outside of your preferred range. Should the AC or furnace not turn on, the thermostat may be broken.

Possible Causes:

The cables connecting the thermostat to the HVAC system might be frayed or disconnected.
Like all technological equipment, thermostats eventually wear out. Should your thermostat be more than ten years old, a replacement might be due.
Should the sensors of the thermostat be faulty, it might not be able to adequately sense temperature variations and so fail to turn on the HVAC system.

3. The HVAC System Not Turn Off

Should your heating or cooling system run constantly, even after your house achieves the designated temperature, the thermostat may not be operating as it should.

Potential Causes:

Should the temperature sensors be covered in dust or malfunctioning, the thermostat could not know when to cut off the system. Sometimes fixing this problem is only cleaning the thermostat.
Check that your thermostat is set to “auto,” not “on.” Set “on,” the fan will operate nonstop even if the HVAC system isn’t actively heating or cooling.
A shorted wire or a wiring design might let the thermostat provide continuous signals to the HVAC system, therefore preventing it from switching off.

4. Inaccurate Temperature Readings

A well-operating thermostat should precisely gauge the temperature of the space and modify the HVAC system in line. Should you find that the displayed temperature does not reflect the real state of the room, the thermostat may have one of the following problems:

Dirt, lint, and other contaminants may build up within the thermostat and compromise its sensors. Help comes by removing the lid and gently brushing the inside.
Should your thermostat be close to a heat source—such as an appliance, window, or direct sunlight—it might indicate inaccurate temperatures. Professionals may move it to a better fit.
Should cleaning and relocation of the thermostat fail to fix the issue, the internal sensors might be malfunctioning and call for replacement.

5. The Thermostat Ignores Change Requests.

Your HVAC system should react one minute or two after you adjust the temperature settings on your thermostat. Shouldn’t there be a response? The thermostat may be broken.

Potential Justifications: Low Battery Power: Should your thermostat run on batteries, poor batteries may cause delayed response.
Loose or corroded wires could cause the thermostat to not be able to efficiently convey signals.
Aging Thermostat: You could be ready for an update if your thermostat is outdated and unresponsive.

6. The HVAC System Short Cycles Frequently, Turning On and Off

When the HVAC system runs but turns off before completing a complete heating or cooling cycle, short cycling results. This might be uncomfortable and cause your HVAC unit to be overused.

Short cycling causes:

If your thermostat is too near a heat source or a vent, it may misinterpret the room temperature and switch the system on and off too often.
A blocked air filter might cause the HVAC system to overheat, therefore inducing brief cycling. Frequent replacement of air filters helps to maintain appropriate airflow.
Should positioning and air filters not be the problem, your thermostat might be broken and need repair.

7. The thermostat loses the set programming values.

Should you have a programmed or smart thermostat, it should keep your preferred settings until you manually adjust them. Should your thermostat often reset itself or lose set values, it might have one of the following problems:

Weak Batteries: Should your thermostat run on batteries, inadequate power might force it to reset.
Software Glitches: Smart thermostats operate on possibly faulty software. Possibly helpful are firmware updates or device resetting.
Frequent power interruptions or wire problems may cause the thermostat to lose memory.

Testing Your Thermostat: Techniques

To be sure your thermostat is the cause of your HVAC problems, do a basic test before replacing it.

How to Test a Digital Thermostat:

For heat, set the thermostat to at least 5 degrees higher than the room temperature now; for cooling, set it to at least lower level.
Hear clicking sounds. Should the thermostat be operating as expected, it should click when turning on the HVAC system.
See if the HVAC system comes on. Should it not, the thermostat may be broken.

How to test a mechanical thermostat?

Take off the lid and, inside, remove any dust or trash.
Look for loose cables and guarantee they are well coupled.
Change the temperature manually, then listen for a clicking sound.

How to repair a broken thermostat?

Should your thermostat prove to be defective, you may attempt several do-it-yourself troubleshooting techniques:

Should your thermostat run on batteries, replace them with fresh ones.
Remove the lid and look for broken or loose cables.
Dust from within the thermostat should be removed using a gentle brush.
Some digital thermostats feature a reset button or may be reset by taking out and reinserting the batteries.
Should these troubleshooting techniques fail, think about replacing the thermostat.

Thermostat Upgrading: Benefits

Changing an outdated or malfunctioning thermostat with a contemporary programmable or smart thermostat has various advantages.

Smart thermostats maximize heating and cooling schedules to save energy use.
Many smart thermostats let you use a smartphone app to change the temperature.
Correct temperature regulation guarantees that your house remains pleasant all year round.

Finally,

Maintaining the comfort and energy economy of your house depends much on your thermostat. Early diagnosis of a thermostat breakdown can save you time and money if you see such indicators. Ensuring that your thermostat runs as it should, whether you clean, fix, or replace it, can help your HVAC system perform effectively for many years ahead.