The Thermostat Is Unresponsive If your thermostat display is dark or blank, even with fresh batteries and no issues with your circuit breaker, your thermostat may be broken. Another indicator is if nothing is changing on the screen when you press buttons.
Standard thermostats: Enlist a friend or family member to assist, Position one person by the thermostat and one person by the furnace. Slowly turn the thermostat from off to heat and increase the temperature. Both the thermostat and furnace should make a sound.
To reset mechanical thermostats, simply turn off the thermostat and flip the circuit breaker. This can be done by going to the breaker panel and turning off the appropriate breaker switch for 30 seconds. After turning the breaker back on, turn the thermostat back on and the thermostat should be reset.
Faulty or Aging Wiring Your thermostat uses a wired connection to communicate with the furnace. These connections can loosen over time. If your furnace suddenly stops working, this could be the issue. In many cases, you can tighten up any loose connections on a low-voltage thermostat.
Temperature Control
The temperature in a home is regulated by the thermostat installed on your living room wall. The thermostat can receive power from the control board in the furnace, or by its own batteries.
There are several reasons why your furnace may not turn on. The most common include a broken thermostat, gas line issues, clogged air filters, blocked ductwork, a tripped circuit breaker, and issues with the furnace itself.
In most cases, installing a new thermostat is a relatively simple do-it-yourself project that can result in improved comfort and convenience and one that can help you save energy.
Replacing a Thermostat. You'll pay between $15 and $300 for the unit in addition to labor ($65 to $100 per hour) to replace an old thermostat with a new one.
If your thermostat is registering incorrect temperatures, then it may be time for a replacement. You can test your thermostat's reading by using a portable indoor thermometer to verify the temperature is correct. The sensor in your thermostat can malfunction from old age, misuse, or manufacturing defect.
If your furnace turns on but no heat is produced, there may be a problem with the fuel supply or the ignition system. If something is stopping your furnace from receiving gas, there is no fuel to combust so the furnace will not create any heat. The furnace turns on but no heat comes out.
Technically, yes, you can run a furnace without a thermostat. Furnaces are designed to operate independently of a thermostat, but the thermostat is an additional device that helps regulate when the system turns on and off. This also depends on the fuel used for your furnace system.
An HVAC system needs power to operate, so if it cannot start, you will be stuck with a thermostat that does not work. If so, ensure your furnace switch is on and your HVAC circuit breaker is set correctly.
While there is a small chance that there is an issue with the running temperature of your engine, by far the most common issue with trouble code P0128 is a faulty thermostat. The exact location of the thermostat and issues related to a damaged thermostat may vary depending on your vehicle.
Pay attention to how often your heating system cycles on and off. Frequent cycling could be a sign of thermostat problems as it struggles to maintain the desired temperature. If the system stays on for extended periods without adequately warming the house then the furnace might be working inefficiently.
If your thermostat is not working properly, it may not be able to accurately read the temperature in your home or properly communicate with your furnace. This can cause your furnace to run continuously, even if your home is already at the desired temperature.