Heat pump not heating in Herndon, VA

A heat pump not heating in Herndon, VA during a cold snap is one of the more common winter service calls a local contractor sees — and one of the more misunderstood.

Before you call — is it actually broken?

• Air from the vents feels cool but the system is running — this can be normal for a heat pump below ~35°F; that's when backup/aux heat should kick in
• Check the thermostat isn't set to "EM HEAT" (emergency heat) by accident, which runs backup resistance heat only and costs far more
• Outdoor unit iced over — some frost in winter is normal, a solid ice block covering the coil is not

When it's a real problem

• No air movement at all from any vent
• The outdoor unit isn't running or cycling on/off rapidly
• A burning smell, unusual noise, or the breaker tripping
• Ice covering the entire outdoor coil that doesn't clear on its own defrost cycle

Herndon's winter swings between mild and genuinely cold snaps stress the refrigerant cycle and defrost controls on heat pumps more than a straight AC-only system — a local contractor who services heat pumps regularly in this climate will recognize the pattern faster than a generalist.

Herndon HVAC contractors who service heat pumps

Not sure it's the heat pump specifically? See our broaderno heat in house triage page.

How this works

Tell us what's happening and we connect you with an independent, licensed HVAC contractor serving Herndon. You contact them directly — we don't sell your information or auction you to multiple contractors at once.