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The thermostat in your home has an important job. It’s what tells your air conditioning system when to heat or cool your home. Hence, it regulates the temperature indoors.
So, when this device begins to malfunction or stops working, it can lead to serious air temperature issues in your house. If you notice your home is warmer or cooler than it should be without changing anything, you may have a faulty bad thermostat.
A bad thermostat could show symptoms like not turning on and off automatically. You may also have problems with the screen or the HVAC system itself. Let’s discuss common problems and how to troubleshoot. Always start with checking your circuit breakers to make sure all units are getting the power they need.
Possible Home Thermostat Problems
There are several symptoms that your HVAC system can display when the thermostat is bad. Here are the top things to consider:
Where is the Thermostat Located?
The first thing you will want to do is investigate the location of your thermostat. Is it in a location that’s near a window or a doorway?
If so, this can cause “problems” with your HVAC system.
When a thermostat is located too close to windows and doors it can make your system think it’s cooler or warmer than it actually is inside your home.
In these cases, the system will send heat or cold air into your home when it’s not needed.
If this is an issue at your home, it may be a good idea to contact a reputable HVAC company and see if they can relocate the device to a better location.
Read Also: Why is My Central AC Running and Not Cooling the House?
The HVAC System will Not Turn On Automatically
When the furnace or air conditioning won’t turn on, most people automatically assume there’s an issue with the actual system. However, this isn’t always true.
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A malfunctioning thermostat can cause problems that won’t allow the system to turn on.
As we mentioned, the thermostat may be in a bad location, thus giving the system a false air temperature. Or it could also be a short in the wiring.
Another thing to keep in mind is that most thermostats contain batteries as a back-up power source. When the batteries fail, it can cause the thermostat to stop working.
The System Will Not Turn OFF Automatically
Another sign that your thermostat is bad is when the system won’t turn off.
When this happens it may be that your thermostat is located in a bad area, or it could also signify wiring or programming issues with your system.
If your system runs for long periods of time, it can be hard on the HVAC unit. It will also raise the cost of your electric bill.
FAN setting– you may think your central air system is running hot/cold when it is actually only the fan running. The circulation fan function simply moves air through the house by the intake grills, and out through the registers. There is no heating or cooling at this time. It should turn off after the program has completed. If not, you have a problem to pursue. Turn the system to “off” to eliminate any chance the fan is running.
The Thermostat is Dirty
Is your thermostat dirty? Dust and other residue can build up on the wiring and other components, causing the thermostat to not work properly. This is especially important with older model thermostats that are more open to the room (top picture). Newer models are more closed and not as likely to have problems.
Cleaning it is easy, simply open the box and wipe the surfaces down – making sure to get all dust out. Doing this small act occasionally can prevent issues from happening in the first place.
The Screen on the Thermostat Won’t Turn On
When your thermostat’s screen isn’t turning on or is only working sometimes, it can cause many problems with your HVAC system.
Sometimes this problem can be fixed by simply completing a factory reset or turning the thermostat off and back on again.
Other times, this is a clear sign the thermostat is bad, and needs to be replaced. A replacement thermostat can be purchased at your local hardware store, or online at retailers such as Amazon starting at around $27 for a simple model. Click here. You can also get smart thermostats that work with your smart phone and have advanced programming options. Most are easy to install with simple instruction guides.
If your thermostat is new, it may still be covered under factory warranty. Problems occurring electronically with your thermostat would fall under factory warranty. This means it will be replaced at no cost to you. Contact the manufacturer or home builder for details.
Note: we may receive a small commission off your purchase at no additional cost to you.
Troubleshooting A Bad Thermostat
Have you noticed any of these things happening with your thermostat? If so, follow the steps below to troubleshoot:
Step #1 – Check the Settings
While this may seem obvious, it’s definitely the first step you should take.
Be sure the system is on COOL for the summer and HEAT for the winter. If your system is running constantly, check to see if it is set to the “ON” position, rather than the “AUTO” setting.
When the system is set to “AUTO” it will turn off and on by itself, according to the indoor temperature detected at the thermostat. This is not an energy efficient way to moderate your temp in your home. You do not want to switch between heating and cooling frequently.
If the programming seems complicated, you can always look up a user manual online for your specific thermostat.
Step #2 – Turn the Thermostat Temperature Up or Down by 5 Degrees
Depending on what season you are currently in, you’ll want to complete one of these steps:
- Summer: Set the temperature 5 degrees cooler than you normally would.
- Winter: Set the temperature 5 degrees warmer than you normally would.
When you adjusted the temperature, did you hear a click? If not, wait a few minutes and check if your registers are blowing air out, and if the return vents are sucking air in. No click and no air flow means the HVAC system is not getting the message to turn on.
If the thermostat itself appears to be working correctly and has batteries, etc., then the problem may be with your HVAC unit. Your furnace may be frozen up, in which case you need a professional to repair.
Step #3 – Replace the Batteries in Electronic Thermostats
If your home is equipped with a digital thermostat, try replacing the batteries inside the device to see if it fixes your problem.
Step #4 – Clean the Thermostat if it’s Mechanical
If your home’s thermostat has a small lever to control the temperature, you have a mechanical device. Over time these commonly malfunction due to a build up of dust.
Remove the cover of the thermostat and dust the inside with a cloth or small brush.
Step #5 – Check Wires and Test Wire Connections
The final step is to remove the cover from the thermostat, and check all wires to ensure they are firmly connected to their mounting screw.
If all wires are properly connected, but the thermostat still doesn’t work you’ll probably need to hire a professional. They will open the device and test each wire individually to determine if any are faulty.
In the end, when you have problems with the HVAC system in your home, don’t automatically assume the system is faulty. Your problem could be something with the thermostat.
Be sure to check if your system is displaying any of the common problems discussed above, and then follow our troubleshooting steps.
If you still have problems contact a reputable professional. Have you dealt with a faulty thermostat before?
Comment now and let us know what the problem was and how it was fixed.
