How to Adjust Thermostat

In cooler regions of the world, or places where it is cold for a major part of the year, thermostats are usually installed at homes or offices. The thermostats help regulate the temperature of the interiors. Not only in cold regions, but in also regions where the temperatures are high or fluctuate usually, thermostats regulate the temperature. A thermostat switches on or off the heating or cooling devices to regulate the temperatures in the interiors. If you too have a thermostat installed in your office or home, you might need to adjust it at times. For this, it is necessary for you to know how to adjust a thermostat, so that you do not need to call your mechanic or service guy again and again for these adjustments in the thermostat.

Thermostats control temperatures using sensors. These are usually a component of an air conditioner or heater. The sensor fit in the thermostat detects the temperature and adjusts the temperature in the interiors accordingly. Latest thermostats can be adjusted by changing its programming. However, it is not so easy for the old ones. Given below is a procedure that will help you adjust the thermostat.

How to adjust the thermostat?

  • Check out the type of thermostat you have. There are basically three types of thermostats – mechanical, digital and manual.
  • Manual thermostats have a lever located above it or at the side. Digital thermostats have numbers indicating time and temperatures. Mechanical thermostats have numbers but do not have time shown on it, and are usually round in shape.
  • Using a screwdriver, remove the cover of the thermostat. Some thermostats have a pull up or pop off cover, which can be removed easily as they do not have any screws.
  • Once you open the cover of the thermostat, check the mercury level. Inside, in a glass vial there is mercury that conducts electricity. It is a liquid and this has to be leveled, to level the temperature.
  • To balance the mercury, the side of the vial that has more liquid, needs to be pushed upwards or downwards. This will level the vial. Even if it does not get adjusted after this, the unit will have to be replaced.
  • In case of manual thermostat, the lever has to be pushed downwards or upwards. The lever pushed in upward direction will heat the surroundings, and pushed in downward direction will cool the surroundings.
  • In mechanical or digital thermostats, you can easily program the temperature by the option available for setting these temperatures. You can also set the temperature you want on a specific date, at a specific time, in these thermostats.

Besides these, there are central thermostats as well. This thermostat needs to be adjusted or checked once in a year. This monitoring becomes necessary from the safety point of view, as well as monitoring your bills.

The procedure of adjusting a central thermostat is given below

  • Uncover the thermostat. Detach the front assembly of the thermostat and check the level of the wall plate.
  • If the wall plate is not leveled, unscrew the mounting screws on it and adjust it. Fix the front assembly as it was, and clean it using a brush. All the contact points and switches need to be cleaned.
  • The thermometer reading on the thermostat has to be adjusted according to the room temperature. A bi-metal coil in the thermostat is the thermometer, and you need to adjust its temperature with the help of a screw driver.
  • If the furnace of the thermostat turns on and off frequently, or very rarely, adjust the anticipator. Moving the pointer towards long setting will help control the turning off and on frequently and vice versa.
  • After this remove the clip, body of the thermostat and insulated wire attached to the R and W terminal at the baseplate. If after this, the furnace turns on, the thermostat needs to be replaced. Also, there might be a problem with the transformer, furnace, or the furnace relay. You need to take help of a technician or mechanic for this.


While adjusting the thermostat, wear rubber gloves and rubber slippers to avoid any hazards. If you are not good at all this it is advisable to get it done from someone who knows it, or call a mechanic.

Adjusting a thermostat is not a difficult task. However, it is a bit difficult for central thermostats. The manual, digital or mechanical thermostats can be adjusted easily by adjusting the mercury level, or the programming. Try to adjust your thermostat next time if you have any problems with its temperature control.

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