How to Calibrate a Thermostat

If you notice your HVAC system running inconsistently or your home not reaching the set temperature, it might be time to calibrate your thermostat. Thermostat calibration is a simple yet effective way to keep your home comfortable and potentially save on energy costs. 

In this guide, HVAC.com explains how to calibrate a thermostat and when to do it. While thermostat calibration is often part of a professional HVAC maintenance tune up, it is possible to do this yourself.

When Does Your Thermostat Need Calibrating?

Over time, thermostats can become less accurate which leads to inefficient heating or cooling. Here are some signs that your thermostat might need calibration:

• Feeling Uncomfortable: Despite setting a specific temperature, you and your family constantly feel too hot or too cold.
• Inconsistent Temperatures: Different rooms in your house feel noticeably warmer or cooler than others, even though your HVAC system is running.
• Higher Energy Bills: A poorly calibrated thermostat can lead to your heating or cooling system running longer than necessary, driving up energy costs.
• Frequent Cycling: An HVAC system that turns on and off too frequently may indicate that the thermostat is not accurately reading the room temperature.
• Inaccurate Display: If the display shows different temperatures within the same area or the temperature seems to fluctuate without reason, calibration might be necessary.

How Often Should You Calibrate?

There’s no one-size-fits-all answer, but generally, calibrating your thermostat once a year is a good rule of thumb. This can be done by a professional as part of your regular HVAC maintenance routine.

Whenever you change the batteries in your thermostat, it’s also wise to check its calibration. New batteries can sometimes affect the device’s accuracy. Any time you have work done to your HVAC system, the thermostat should be checked as well, as this work may impact it.

However, if you notice temperature issues at any point, you don’t have to wait for your annual maintenance appointment to investigate. Addressing thermostat issues right away can help you restore comfort and lower energy waste.

Do I Need to Have My Thermostat Professionally Calibrated?

Depending on your thermostat type, calibrating a thermostat yourself can be a straightforward process if you follow the right steps and have a basic understanding of your HVAC system.

Still, not every homeowner is comfortable with how to calibrate a thermostat. In this case, you should contact your HVAC technician to test and calibrate your thermostat. Professionals have the expertise and tools needed to handle various thermostat models and can identify other potential issues with your HVAC system.

How to Calibrate a Thermostat

Here are the general steps for calibrating a thermostat. Remember, this is a guideline, and specific steps may vary depending on your model.

1. Gather your tools: You’ll likely need a reliable thermometer, a small screwdriver, and your thermostat’s manual.
2. Place the thermometer: Position an accurate thermometer on a wall near your thermostat, but away from direct sunlight or drafts. Place it at a similar height as the thermostat.
3. Wait for adjustment: Allow 15-30 minutes for the thermometer to adjust to the room temperature.
4. Compare readings: Check the difference between the thermostat’s displayed temperature and the thermometer’s reading. If they differ by more than a degree or two, calibration is needed.
5. Making adjustments: Depending on your model, you might have a calibration screw or buttons to adjust the displayed temperature to match the thermometer’s reading. Make small adjustments at a time and wait for the system to respond before making further changes. Some thermostats have a dedicated calibration mode. Consult your manual for instructions on accessing it.
6. Test and recheck: Once you’ve adjusted the thermostat, monitor your home’s comfort level and the thermometer’s reading over the next few days. If needed, fine-tune the calibration further.