Always follow the thermostat manufacturers instructions whenever changing the thermostat. Always turn the power off at the air handler and the condenser and make sure there is no voltage at the transformer before proceeding. The colors below are the most likely colors used for most installations however your thermostat wire colors may be different than what is indicated here. There is no official standard for thermostat wire colors. Thermostat wiring colors are not standardized but these are the most wiring methods used based on my years of experience in the HVAC field where I successfully wired a lot of thermostats. For instructions on how to wire a thermostat please see our how to wire a thermostat page.
The main connection between the air conditioning and heating system and the end user is the thermostat. Beyond the air conditioning and heating thermostat many people know nothing about their systems that keep them comfortable year round. There comes a time when the thermostat has a problem or the end user wants to replace the thermostat because they think it is a broken thermostat. It is not uncommon for a person to call an HVAC contractor and tell the secretary that they think the thermostat is broken because their air conditioner or heating system does not work. In some instances this is the case while in others the thermostat is not broken but something is wrong with the air conditioning and heating equipment that needs to be repaired. In either case it is usually best to call an HVAC professional to look at the problem especially if you want to replace the thermostat. There are a few things you can check with your thermostat before you call an HVAC professional. A little thermostat troubleshooting is in order.
The thermostat display is our interface with our HVAC equipment. The display lets us know what the temperature is in the house and tells us what the settings are for the heating and cooling equipment including letting us know the set point setting for the temperature. Some displays give us the time and the newer modern displays show us family photos like a screensaver on our computer. But what happens when the display is not there or there is a blank thermostat display or no display on thermostat? Is it a bad thermostat or something else that caused the display to disappear?
Your thermostat or programmable thermostat is an integral part of your comfort system. These thermostats, whichever type of thermostat or thermostats you have, require little maintenance. Often, I find that the only thing people know about their AC and Heating systems is how to turn the thermostat on and off and change the temperature setting. The purpose of this site is to help people go beyond the thermostat and learn more about their system as a whole, not just a dial on the wall that adjusts the temperature when they are not comfortable. However, we’ll delve into the world of thermostats on this page and hopefully this will help many people.