Heat pump repair and replacement in Herndon, VA

A heat pump is an air conditioner that runs backwards in winter. That means it can fail in two seasons, in two unrelated ways, and that the winter failures are the ones most often misread.

Herndon contractors listed under Heat Pump Repair & Replacement

These are the businesses we list in Herndon whose own services include this work. We report what each listing says — we do not assess or rank workmanship. Paid members appear first.

Other HVAC contractors in Herndon

Listed for other HVAC work, and not listed for this. That is a gap in what we know about them, not a statement that they will not do it.

What this work covers

• Reversing valve faults
• Defrost boards and defrost sensors
• Auxiliary and emergency strip heat
• Refrigerant charge, which matters more here than on a cooling-only system
• Outdoor coil and airflow

The call that comes in as "my heat pump isn't heating" is usually one of three things, and only one of them is expensive. Either the reversing valve is not switching the system into heating, or the defrost cycle is stuck or failing, or the unit has quietly fallen back on auxiliary electric strip heat and is heating the house at several times the running cost. The third is the one nobody notices, because the house is warm — it announces itself on the electric bill rather than at the thermostat.

Steam rolling off the outdoor unit on a cold morning is normal. That is the defrost cycle melting frost off the outdoor coil, and it is supposed to happen. What is not normal is a coil that stays iced over through several cycles, which points at the defrost control, the sensor, or a charge problem rather than at the weather.

Charge accuracy matters more on a heat pump than on a straight air conditioner, because the same refrigerant circuit has to work in both directions across a much wider range of outdoor temperatures. A charge that is slightly off is tolerable in July and is the difference between running on the compressor and running on strip heat in January. Northern Virginia sits in the band where heat pumps spend real time near their balance point, so it is worth asking what that balance point is set to and whether the system is actually reaching it.

Contractor data sourced from public web research and cross-checked against the Virginia DPOR License Lookup where noted — the board's own data is not the official public record and may be stale; verify independently before hiring.