Problems With Furnace Thermostat:
The method of testing a furnace thermostat that uses natural gas, oil, or propane is the same. As an alternative to your furnace or air conditioner, your home’s thermostat may be malfunctioning.
Your thermostat most likely lost power if the display was not lit and neither the heat nor the cold air responded to your orders. Your thermostat can be broken if a battery swap doesn’t work to fix it.
Will a malfunctioning thermostat prevent the heater or air conditioner from turning on? Yes, if there is a wiring issue that hinders the transmission of these signals. When you order it, your thermostat sends electric impulses via cables to your heating or cooling system. A problem with these wires may prevent communication with your furnace or air conditioner.
Similar to this, if your heater or air conditioner won’t switch off when you instruct it to, your home thermostat may malfunction. This may indicate that the thermostat needs to be calibrated properly or that there is a wiring issue.
Despite what your thermostat reads, the temperature in the room may feel different to you. If your measurement of the room’s temperature differs from the thermostat’s read, your home’s thermostat is likely malfunctioning.
How To Test Furnace Thermostat:
With a few quick tests, our detailed tutorial demonstrates how to determine whether your house thermostat is malfunctioning.
Step 1: Lower or Raise The Thermostat
If you set the thermostat 5 degrees higher or lower than usual, check to see if the heat or air conditioning comes on.
Step 2: Verify The Thermostat Is Turned On
Despite how obvious it may sound, buttons are accidentally pressed. Verify that the thermostat is on and that the HEAT or COOL setting is chosen.
Step 3: Examine The Wiring
Switch off the breaker for the thermostat. Check the wiring for good attachment and tightness of the screws by opening the thermostat cover.
Step 4: Restart The Breaker
After switching the breaker back on, check to see if the thermostat illuminates and operates as intended. Retest by turning the breaker on and off once again if the thermostat doesn’t operate or looks to be defective.
Step 5: Check Wires Again
Check the breaker is off before looking again at the thermostat wires. For the AC, look for the red and green cables, and for the furnace, the red and white wires.
Step 6: Conjoin The Wires
The AC or furnace wires should be unplugged from their ports and wrapped around one another. Re-engage the breaker. Your thermostat is probably the source of the issue if the AC or heat comes on.
- Remove the thermostat or thermostat cover to expose the wires when the furnace’s power is off. You should take note that the wires need to be screwed into terminals with the letters R (red), W (white), G (green), Y (yellow), and C. (common). Some thermostats only have connections for Red and White or Red and Green. In the video at the end of this post, you can learn more about recognizing the different wires. Take note of the cables that are attached to the terminals or, even better, use your smartphone to take a picture.
- To remove the wires from their terminals, unscrew them. Do not allow them to enter the room again through the wall hole (wrap them around a pencil if necessary). Pick Red and White if there are more than two wires; generally, electricity and heat are represented by these colors.
- The two wires’ ends should be twisted together. Verify that none of the other wires are in contact with any of these lines or with one another.
- Reconnect the furnace’s electricity. If the blower turns on and the furnace burner ignites, the thermostat was either malfunctioning or improperly connected to the wiring. A new thermostat should be installed, as explained in the article. If the burner won’t light, look for breaks in the wires leading from the thermostat to the furnace by testing their continuity. (Only the blower will be on if you are checking the air conditioning.)
- All wire connections’ terminal screws should be checked and tightened. Repeat these steps with the Red and Yellow if the AC isn’t working. Repeat with the Red and Green if the fan isn’t operating.