When your air conditioning stops working, it can spell disaster—especially if it’s in the middle of summer! You don’t want to deal with the heat or declining indoor air quality. It’s not always easy to find the source of the problem, but sometimes, it’s a simple thing like a thermostat issue. Luckily, many common thermostat problems are easy to fix.
If you suspect your thermostat isn’t working correctly, read on. There are several possible reasons your thermostat might not be performing up to par.
Don’t overlook the easiest solution! One common problem is an incorrect setting that causes the HVAC to stop working. It’s easy to inadvertently turn a timer on or perform some other keypress that makes the system mysteriously turn off!
What to do: With any HVAC misbehavior, it’s always best to check your thermostat settings first, as this is often the culprit.
If your HVAC system inexplicably stops working altogether, it doesn’t mean disaster. Sometimes fixing the problem is as simple as replacing dead batteries. Many modern HVAC systems have digital thermostats that use battery power as an auxiliary supply. Often homeowners don’t realize that this part of the system doesn’t use your electricity supply. The reason why digital thermostats use batteries is that they provide a backup power source. This ensures that in the event of a brief interruption to the electricity, settings and other programmed information are retained.
If the problem with your thermostat is low or dead batteries, the display screen will turn blank. The thermostat will stop working, and the HVAC won’t function at all. This might startle you, but the solution is just to replace the batteries.
What to do: All you need here are some fresh batteries. Depending on your thermostat model you may need a small flat-head screwdriver too. If you need to, use the screwdriver to remove the screws on the thermostat wall plate, then gently release the plate. Locate the dead batteries then replace them with fresh ones. Refer to your HVAC user manual if you have trouble removing the wall plate or locating the batteries.
Another reason that the HVAC may suddenly stop working is that the thermostat’s electrical power supply has been interrupted.
What to do: Check your main electrical service panel for obvious issues such as a tripped breaker or a blown fuse. Either of these issues can interrupt the power supply to the thermostat and cause it to stop working.
If you’ve established that the thermostat is correctly receiving power, the next step is to peek into the thermostat box and see how clean it is. A dirty thermostat can play havoc with the entire HVAC system. Interior dirt and dust can interfere with both electrical and mechanical components. Pets, plants, an open fire, and smoking can contribute to a buildup of debris that might prevent the thermostat from functioning.
Grime buildup can mean the thermostat stops working at all, but in some cases it may make the thermostat less accurate. This can lead to an inconsistency between the temperature the thermostat displays and the actual temperature in the room.
What to do: To safely check the thermostat, first shut off the thermostat breaker. Then remove the wall plate, and examine the interior for signs of dust, grime, and other debris. If there is a buildup in the thermostat’s interior, you can clean it with a soft brush or a can of compressed air. Be sure to use a light touch here.
At the same time, you can also check for obvious issues such as loose screws or corrosion. If you see any trouble spots, you can call a CW HVAC technician for professional help. If you live in North Texas, give CW Service Pros a call.
The wiring that connects the thermostat to the electrical service panel may become loose or otherwise faulty over time.
What to do: If you suspect your thermostat issue is due to loose wiring, call CW and ask for an appointment with your favorite HVAC technician. It’s best not to DIY this unless you’re a trained HVAC technician or electrician.
Does it seem like your home never actually gets to the right temperature? Is the HVAC short-cycling or running continuously? There are other reasons why these issues can happen, but sometimes it’s a thermostat problem.
If the thermostat isn’t level, it can affect the interior mechanism that calibrates temperature. So, when you set a particular temperature on the thermostat, the thermostat interprets that setting as something different. It may only be a few degrees off, but it can make a big difference in the comfort level in your home!
What to do: Use a level to determine how the thermostat should sit, then adjust it until you hit the sweet spot.
A heat anticipator is a mechanism inside some thermostats that helps them function more accurately. The heat anticipator functions to prevent temperature overshoot. It causes the thermostat to switch off just before the room reaches the set temperature. If the heat anticipator is stuck, it means it stops performing this function, which may lead to room overheating. Note that many newer models don’t have heat anticipators, but instead use a thermistor to sense room temperature.
What to do: Remove the thermostat cover and locate the heat anticipator. It looks like a small metal “arm” that sits on a circular dial. Pushing the arm very gently should free it up so it can function normally again.
Another cause of a thermostat not working is poor calibration of the heat anticipator. This is important, because incorrect calibration means the anticipator will switch the thermostat off either too soon or too late. Poor calibration can mean room temperatures are consistently either too low or too high.
What to do: The heat anticipator sits on a circular dial that’s marked with a number of increments. You can adjust the arm in two different directions, depending on whether you want to make cycles shorter or longer. Refer to your owner’s manual to determine which way you need to calibrate, as it’s not the same for all thermostat models.
The place where your thermostat is situated can have a big effect on how accurately it operates. If the thermostat is in a place that exposes it to direct sunlight or drafts, or anything else that might influence temperature, it may be unable to reach or maintain the temperature you set.
It’s also important that the thermostat is in a central location in the main living areas of the home. The thermostat needs to be able to detect the home’s average climate in order to maintain the most desirable temperature. If the thermostat is in an out-of-the-way spot with very different indoor air conditions than the main living areas the thermostat will be unable to detect what the home’s average temperature is and keep the temperature right.
What to do: Relocate your thermostat to a more suitable place that’s near the main living areas in your home, and is protected from drafts, sun exposure, and temperature extremes.
Thermostat problems can be tricky to solve. Some issues have a simple fix, while others need some professional assistance. If you need help fixing a broken thermostat, you can always call CW Service Pros for expert HVAC advice in Dallas and the surrounding suburbs.
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