A bad thermostat can be detected when your AC or furnace is not turning on, your HVAC systems are not turning off, the thermostat not responding, your HVAC system is short-cycling, the room temperature not matching the temperature displayed on the thermostat, and the programmed setting resetting themselves.
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.
The Lifespan of a Thermostat
On average, most thermostats last about 10 years, depending on the model, usage, and proper maintenance. However, many people decide to replace their unit sooner to take advantage of new energy-saving technologies.
It could be displaying an inaccurate temperature. In this case, your car may not be overheating, but your temperature gauge won't be able to warn you. Thermostats can often go bad after about 10 years of use.
To test them, switch your thermostat “off,” and then switch back to “on.” Set it to the heating or cooling mode, and turn it up or down, depending on the season. Some thermostats will make a clicking sound when they turn on — you might even hear your HVAC system click on as well.
To do so, locate your home's thermostat and tape an accurate thermometer on the wall next to it. Wait 15 minutes and check the temperature reading on both devices. If your readings are three or fewer degrees apart, you should be good to go.
One easy thing you can do to check the accuracy of your thermostat is to do a temperature check. See what your thermostat reads. Then use a portable indoor thermometer to compare the temps. Another good way to do the temperature check is to download one of the many free apps that allow you to check indoor temperatures.
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. However, installing a brand-new thermostat is more involved and, therefore, more expensive.
P0128 is an extension of OBD-II code P0 which indicates a problem with your car's coolant thermostat.
To reset a non-programmable digital thermostat, you'll need to take the face-off and hold the reset button for five seconds. You can also try removing the batteries for five seconds. Both of these methods should result in a reset thermostat.
Upgrading to a new thermostat can feel daunting, but with a systematic approach, it's a manageable DIY project. This guide will walk you through each step, ensuring a smooth and successful installation.
The Heater or AC Unit Won't Start.
When the wiring between the thermostat and the air conditioner, furnace, or heat pump comes loose, it will break the connection and leave you cold. Wiring defects can also cause the system to misread temperature settings.
Most modern thermostats will have a clearly marked reset button inside the panel. It's usually small and recessed, so you might need a pointed object like a paperclip to press it. For those wondering specifically how to reset air conditioner thermostat models, the process is generally the same.
Yes, many smart thermostats are designed for DIY installation, and manufacturers typically provide step-by-step guides and videos. However, if your HVAC system is older or lacks proper wiring (like a C-wire), the installation might become more complex, and you may need professional help.
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.
You can determine if the wiring is defective by turning the fan from the “Auto” setting to the “On” setting. The blower should start, which means your thermostat is getting power. Or, if the AC is on, turn the temperature down; if the furnace is on, turn the temperature up.