Heat pumps provide both heating and cooling — when they fail, they take both functions offline. Local contractors diagnose and repair heat pump systems across Greenbrier and Robertson County year-round.
Greenbrier grew up as a farm town along Highway 41 between Springfield and White House, in Robertson County's dark-fired tobacco belt -- a crop that's still grown in the surrounding fields even as the town itself has changed shape. What used to be a small crossroads has picked up a steady run of new subdivisions over the last fifteen years as Nashville's growth pushed commuters north up the corridor looking for a shorter drive and a lower price than closer-in suburbs offer. That's left Greenbrier with two distinct housing generations side by side: older farmhouses and modest ranch homes on larger lots outside the town core, many with HVAC systems that have been patched and replaced piecemeal over the decades, and newer subdivision construction built to more current code with tighter, more uniform ductwork. The town's summers carry the same humid, high-load stretch as the rest of Middle Tennessee, and winters bring enough hard-freeze nights that a furnace or heat pump with a marginal repair history tends to show its weak point on the coldest night of the year rather than a mild one.
Heat Pump Problems We Fix
Common heat pump failures include reversing valve problems that prevent the system from switching between heating and cooling modes, refrigerant leaks, defrost board failures that cause ice buildup on the outdoor unit, compressor issues, and auxiliary heat problems. Heat pump diagnostics require specialized knowledge of the refrigerant cycle in both directions.
System runs constantly but never quite reaches the set temperature
This often points to a refrigerant or airflow issue rather than a thermostat problem — a technician can check charge levels and airflow before assuming the system itself is undersized.
Outdoor unit is covered in ice, even when it's not especially cold out
Some frost during a normal defrost cycle is expected, but heavy ongoing ice buildup usually means the defrost cycle isn't completing correctly or airflow is restricted.
Noticeably higher electric bills with no change in usage habits
A system working harder than it should to hit the same comfort level is a common early sign of a developing mechanical issue, often before anything sounds or feels obviously wrong.
Heat Pump vs. Furnace in Middle Tennessee
In Middle Tennessee's climate, heat pumps are efficient down to certain outdoor temperatures, after which auxiliary or emergency heat takes over. If your heat pump is running but not keeping up in cold weather, the issue may be with the auxiliary heat source rather than the heat pump itself. The technician checks the full system.
- A summer repair does not verify the heating side. The reversing valve, defrost control, and auxiliary heat are not exercised in cooling mode and can only be tested under heating conditions.
- A heating repair does not confirm the cooling side either, for the same reason in reverse.
- Repair restores the equipment's rated capacity; it does not compensate for ductwork or insulation that limits what reaches the rooms.
- Auxiliary heat operating on the coldest nights is designed behaviour, not a defect to be repaired out of the system.
- Because both modes run through the same equipment, a fault deferred in one season is usually still waiting in the next, which is the practical argument for testing both modes at a single visit.
This content is reviewed by the Clarksville HVAC Repairs editorial team and informed by licensed-contractor sourcing, manufacturer documentation, and established industry standards for hvac repair. Read our editorial standards.