A thermostat is a device that controls the temperature of your heating and cooling system. It senses the temperature in your home and sends signals to the HVAC system to turn on or off accordingly. However, sometimes the thermostat may not be accurate and may cause your home to be too hot or too cold. This can affect your comfort and energy efficiency. To fix this problem, you may need to recalibrate your thermostat.
Recalibrating a thermostat means adjusting its settings so that it matches the actual temperature in your home. There are different types of thermostats, such as mechanical, digital, and smart thermostats, and each one may have a different method of recalibration. In this article, we will explain the basic steps of how to recalibrate a thermostat for the most common types: mechanical and digital thermostats.
How to Recalibrate a Mechanical Thermostat
A mechanical thermostat is a simple device that uses a metal coil or strip that expands or contracts with temperature changes. A mercury switch or a contact point is attached to the coil or strip and moves along with it. When the switch or contact point reaches a certain position, it triggers the HVAC system to turn on or off.
To recalibrate a mechanical thermostat, you will need a screwdriver, a level, and an accurate thermometer. Here are the steps to follow:
- Turn off the power to the HVAC system at the circuit breaker or the main switch.
- Remove the cover of the thermostat and locate the calibration screw or dial. It is usually marked with “CAL” or “ADJ” and is attached to the coil or strip.
- Place the thermometer next to the thermostat and wait for 15 minutes. Make sure both devices are away from any external sources of heat or cold, such as windows, doors, vents, or appliances.
- Compare the readings on the thermostat and the thermometer. If they are the same or within one degree of each other, the thermostat is calibrated correctly. If not, proceed to the next step.
- Use the screwdriver to turn the calibration screw or dial until the thermostat reading matches the thermometer reading. You may need to turn it clockwise or counterclockwise depending on the direction of the error. For example, if the thermostat is reading too high, you need to turn it counterclockwise to lower it.
- Wait for another 15 minutes and check the readings again. Repeat the adjustment until the readings are the same or within one degree of each other.
- Replace the cover of the thermostat and turn on the power to the HVAC system. Test the thermostat by setting it to a desired temperature and observing if the HVAC system responds accordingly.
How to Recalibrate a Digital Thermostat
A digital thermostat is a more advanced device that uses a sensor and a microprocessor to measure and control the temperature. It has a digital display that shows the current and desired temperature settings. It may also have buttons or a touchscreen that allow you to adjust the settings and program the thermostat.
To recalibrate a digital thermostat, you will need an accurate thermometer and the user manual of the thermostat. Here are the steps to follow:
- Turn off the power to the HVAC system at the circuit breaker or the main switch.
- Place the thermometer next to the thermostat and wait for 15 minutes. Make sure both devices are away from any external sources of heat or cold, such as windows, doors, vents, or appliances.
- Compare the readings on the thermostat and the thermometer. If they are the same or within one degree of each other, the thermostat is calibrated correctly. If not, proceed to the next step.
- Access the calibration setting on the thermostat. You may need to consult the user manual for the specific instructions on how to do this. Some thermostats may have a calibration mode that you can enter by pressing a combination of buttons. Others may have a calibration option in the menu that you can access by using the touchscreen or the buttons.
- Adjust the calibration setting until the thermostat reading matches the thermometer reading. You may need to enter a positive or negative value depending on the direction of the error. For example, if the thermostat is reading too high, you need to enter a negative value to lower it.
- Save the calibration setting and exit the calibration mode or the menu. Wait for another 15 minutes and check the readings again. Repeat the adjustment until the readings are the same or within one degree of each other.
- Turn on the power to the HVAC system and test the thermostat by setting it to a desired temperature and observing if the HVAC system responds accordingly.
