Furnace repair in Herndon, VA

Heating faults split cleanly into two groups: the furnace will not start, and the furnace starts and then stops. They have different causes, different urgency, and only one of them is routine.

Herndon contractors listed under Furnace Repair

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

• Ignition faults — hot surface igniters and flame sensors
• Limit and pressure switches shutting the furnace down
• Blower motors and control boards
• Gas valve and burner faults
• Heat exchanger inspection

A furnace that lights and then quits after a minute or two is usually not broken in the way it looks. It is a furnace whose safety controls are doing their job — a flame sensor that has oxidised and can no longer confirm the burner is lit, a limit switch tripping because airflow is restricted, or a pressure switch that cannot prove the exhaust is actually leaving. Cleaning a flame sensor is a small job. Diagnosing why a limit switch keeps opening is the real work, and it usually points at airflow rather than at the furnace.

The reason this service gets treated differently from air conditioning is combustion. A gas furnace makes carbon monoxide by design and vents it outside; a cracked heat exchanger is the failure that lets it into the house instead. That inspection is the part of a heating repair worth insisting on, and a contractor who condemns a heat exchanger should be able to show you what they saw. A furnace that is red-tagged and shut off is being taken out of service for a reason, not as a sales tactic — but it is also the point at which a second opinion costs you nothing but a day.

Timing works against you here in a way it does not in summer. The first genuinely cold night in Northern Virginia produces a queue, because that is the night every marginal furnace in the region is asked to run. A furnace that behaved oddly in October is far cheaper to look at in October.

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.