Before assuming that your central heating system has failed, check the thermostat. From overworked systems to those that seem to have quit working altogether, a faulty thermostat can disguise itself as other problems. Before calling an HVAC repairman, try the thermostat troubleshooting steps below.
The Basics of Thermostats
Thermostat temperature sensing and response varies according to whether the thermostat is electronic or electromechanical.
- Electromechanical thermostats are a bit old-fashioned, operating on rudimentary principles. A metal strip rests under a cover, and as temperatures rise and fall, the contact is activated. Without contact between the strip and its coil, the heating system will not function.
- Electronic thermostats have heat receptors that monitor temperature, and circuits that read and respond to the data they receive. These thermostats are programmable, and provide greater control. However, they wear out quicker because they contain more parts, and in many cases replacement is more cost-effective than repair is.
Common Issues With Thermostats
Most thermostat failures happen over time. A malfunction may be obvious, such as when the display won't light up or the heat won't come on, or you might notice that the house is cooler than normal. Many heating issues and causes overlap one another, and solutions can usually be narrowed down to a select few.
If the furnace won't start:
- Check it for power. Blown fuses, dead batteries and tripped breakers can prevent the thermostat from working as it should.
- Check the thermostat for cleanliness. Buildup of dirt and dust can interfere with mechanical and electrical parts. Use a soft brush to gently clean interior components, or use an air duster.
- Inspect the thermostat for loose screws and connections. If loose wiring is found, call an HVAC repair tech as soon as possible.
If room temperature and thermostat reading don't match:
- Check the inside of the thermostat for dust and dirt buildup.
- Ensure that the thermostat is level.
- Note the thermostat's location. Placing a thermostat in direct sunlight, in front of a drafty window or out of the main living area can all result in inaccurate readings.
If the above troubleshooting steps don't have the desired result, consider hiring an HVAC repair company like A Avis Plumbing Heating & Air Conditioning to replace your old, outdated thermostat with a new electronic model. With a range of prices and features, you can find one to fit your budget. Touch screens, digital displays and filter change reminders make new thermostats a very convenient addition to your home.