How to Calibrate Your Thermostat
admin • December 2, 2011

Have you ever set the thermostat in your Cornelius home to a desired temperature and “hoped for the best?” Maybe it’s because the temperature setting you expected this finely tuned instrument to maintain just isn’t right. You may see 70 degrees on the thermostat but the home feels more like 65 degrees. In fact, if you used a hand-held thermostat, you might get real proof that your thermostat is not working like it should.

There are reasons for a malfunctioning thermostat and solutions to correct them, namely calibration. First, let’s look at some reasons why a thermostat can be out of kilter.

The first thing to note is that thermostats are very sensitive instruments and change to the slightest changes in temperature. An incorrectly installed thermostat or one that is accidentally bumped or jarred can malfunction. It may wind up out of level, causing it to operate incorrectly. Possibly the most common problem affecting accuracy is a build-up of dirt, which can affect the calibration of the thermostat. Other problems may be caused by loose wiring.

Here are some steps you can take to check your thermostat for accuracy and recommended actions.

  1. Use a standard glass thermometer to check the room temperature. You should mount it on the wall nearby your thermostat and use some padding to keep it from actually coming in contact with the wall, which could affect the readings.
  2. Wait 15-30 minutes for the thermometer to adjust to the temperature and enable it to give the most accurate reading. Once the time has elapsed, compare its temperature reading to that on your thermostat.
  3. If there is more than a one degree variation, your thermostat may be dirty. Remove its faceplate and examine it. If there is dirt or dust inside, blow it out. If you can reach the contact points, you can clean them with a new dollar bill (and speaking of dollars, a clean and accurate thermostat will make your furnace run more efficiently and save you money on your utility bill).
  4. Some thermostats use a mercury vial which can indicate if the thermostat is level or not. If it is not level, a simple adjustment using a screwdriver may do the trick. In the worst case, you may have to remove the thermostat and drill a new hole to reinstall the mounting screw in a different location.
  5. Now that you have made these corrections, check both thermostats to see if the temperatures match. If they don’t, try steps 3 and 4 again. If that still doesn’t work, your problem may be more than just a dirty, lopsided thermostat. You may need to replace the thermostat – or even look at the heating system in its entirety. It could be time to call a professional heating contractor to check out your entire system.

Today’s thermostats have few working components but are very sensitive, advanced instruments. It takes little to throw off a thermostat but luckily, it takes little effort to correct the resulting problems.

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