Overheating HVAC components typically don’t overheat for very long. Either an internal safety sensor automatically shuts off the unit to prevent fire or the affected part incurs permanent damage and totally fails. Either way, you’re stuck with no heating or cooling until the problem can be diagnosed and repairs or a replacement are done by a qualified HVAC service technician.

Needless to say, there’s no convenient nor inexpensive time for overheating HVAC components to occur. These are some of the typical causes and results:

• A dirty filter. A clogged air filter can eventually obstruct system airflow entirely. If you’re running the furnace, that means a safety switch may shut down the unit until professional service arrives. Airflow restricted by a dirty filter also affects central air conditioners by causing the compressor — usually the system’s most expensive component — to run excessively long cycles, overheat, and possibly incur permanent damage that requires replacement. Replace the air filter as recommended by the filter manufacturer.
• Closed vents. An overheated furnace is one more reason why closing supply vents in individual rooms is a bad idea. Too many closed vents excessively reduces furnace return airflow. In turn, this can build up heat in the furnace heat exchanger, potentially causing damage that requires expensive replacement. (A cracked heat exchanger may allow seepage of toxic fumes like carbon monoxide into the system’s airflow.) A better idea is to keep all vents in all rooms open at all times.
• Low refrigerant. The refrigerant level circulating through your central A/C carries heat from the indoor evaporator coil to the outdoor condenser coil. If refrigerant is below specs, ice may form on the evaporator coil, eventually obstructing airflow entirely. As this is occurring, the compressor runs longer and harder, eventually overheating and shutting down, or perhaps sustaining permanent damage. Low refrigerant always means a leak requiring professional HVAC service to detect and repair it.

The professionals at Jackson & Sons are ready with prompt, professional service to resolve overheating HVAC issues in your home.