Understanding Thermostats and How They Work

Understanding Thermostats and How They WorkThe thermostat is the control center of your HVAC system, so it affects how your heating and cooling components perform, their energy efficiency, and the comfort level they provide. Given the importance of the thermostat, it’s beneficial to have a general understanding of the type you own, how it works, and whether you need help from an HVAC pro when problems develop.

Types of Thermostats

There are two main types of thermostats used with home HVAC systems; mechanical and electronic:

  • Mechanical units have a coiled bimetallic strip that expands/contracts as the temperature changes. To provide temperature control, they use two internal contacts that can be adjusted via the thermostat’s external dial. When the coil connects with one of the contacts, the thermostat signals the HVAC equipment to start up or shut off.
  • Electronic units use a thermistor to measure temperature based on changes in electrical resistance. Most have a digital display screen, and many can be programmed with personalized temperature setbacks for energy savings. Some models have PID controllers and work with modulating HVAC equipment, but the most advanced are “learning” thermostats that provide intuitive control of a home’s temperature and comfort, and the HVAC equipment’s performance and energy use.

Expert Help is Often Needed to Solve Thermostat Problems

Oftentimes, it’s not easy to know if a problem you’re experiencing originates with the thermostat or your HVAC equipment. In situations like the following, it’s best to have an HVAC pro make a diagnosis:

  • Unresponsive equipment. It’s usually easy to fix a blank thermostat screen by replacing the batteries. If the display is fine but the HVAC doesn’t cycle on, though, there may be wiring problems, or issues like a frozen cooling coil.
  • Poor temperature control. If the room temperature doesn’t match your thermostat’s temperature setting, the unit may need to be re-calibrated, or there might be a refrigerant leak.
  • Recurrent short cycling. Short cycling can occur if the thermostat needs an internal cleaning, but oversized equipment capacity is another possible culprit.

For expert help solving thermostat-related problems in your Indianapolis home, contact us today at Mowery Heating, Cooling and Plumbing.

Our goal is to help educate our customers in Brownsburg, Indiana and surrounding areas about energy and home comfort issues (specific to HVAC systems).