Some of the common reasons for thermostats breaking include the thermostat being placed too close to a heat source, not being in a central location or being dirty. Homeowners who use mercury thermostats are advised to upgrade to newer digital models.
A thermostat that is located too close to a heat source gives a false reading, usually of a higher temperature. This in turn causes the heater to turn off prematurely, leaving the house cold. Homeowners are advised to locate their thermostats away from stoves, ovens, fireplaces and direct sunlight.
The thermostat should be located in a central location in the home, preferably a hallway. This helps to ensure even temperature distribution. A thermostat that is not placed in a central location may cause parts of the home to be warmer than others. Zoning is required if the problem persists despite the thermostat being properly located.
Thermostats accumulate dirt over time, causing them to give incorrect readings and, eventually, to stop working. Homeowners should remove the plastic housing, and wipe off the dust with a clean cloth. Finally, old thermostats, specifically those that use mercury are prone to breaking. These should be replaced with newer digital models, which are also more accurate.