Furnace Blowing Cold Air

Cool air out of the registers means the fan half is healthy and the fuel half quit, which shouldn't be left alone with a cold front coming.

Tap to CallNumber arriving soon

When this becomes an emergency

The vents are moving air that feels cooler than the room it's entering.
Long runs go by with no change in indoor temperature.
The burner catches for a few seconds and then gives up.
The unit refuses another attempt until power has been cycled at the switch.

What a pro does

A furnace pushing cold air has already told you the blower's fine. The technician follows the ignition sequence from the beginning, confirming that the inducer starts, that the pressure switch closes, that the ignitor heats, and that the flame sensor sees what it should. Exterior vent terminations get real attention here, since blowing snow packs into a sidewall pipe on the windward face of a house and stops the burner without leaving any clue indoors. On propane systems, regulator performance in deep cold belongs on the same list. A control that has latched into lockout gets reset once for a look, never forced repeatedly.

Frequently asked questions

How does wind-driven snow shut down a furnace?

Sealed-combustion units breathe through pipes on an outside wall. Snow packed into the intake or exhaust keeps the pressure switch from proving, and the board refuses to light the burner.

Is a dirty flame sensor really that common?

It's near the top of the list. A film of residue on the probe hides the flame from the control board, which shuts the gas valve within seconds of ignition.

Does it help to keep the fan on manually?

It moves air around the house but adds no heat, and on a very cold day circulating unheated air can make rooms feel worse rather than better.

Why does the problem seem to happen only at night?

Cold and wind both peak overnight, and marginal parts fail when they're pushed hardest. That's why a unit can behave perfectly for the technician at two in the afternoon.

Furnace Blowing Cold Air?

Get connected with a local pro now.

Tap to CallNumber arriving soon

Keep going

Heating in the Sioux Falls and Rapid City areas Boiler Leaking Water Emergency Heating Repair Furnace Making Loud Noise Furnace Short Cycling Heat Pump Frozen Outside No Heat Pilot Light Keeps Going Out Radiators Not Heating Thermostat Not Working

disclaimer: 605 Heating is a free service to assist homeowners in connecting with local service providers. All contractors/providers are independent and 605 Heating does not warrant or guarantee any work performed. It is the responsibility of the homeowner to verify that the hired contractor furnishes the necessary license and insurance required for the work being performed. All persons depicted in a photo or video are actors or models and not contractors listed on 605 Heating.

Same-day and 24/7 emergency services are subject to provider participation, location, technician availability, and demand. Availability is not guaranteed and may vary by market and appointment capacity.

We use cookies and session-based analytics, including session replays (with form inputs masked), to improve this site. See our Privacy Policy.

About · Contact · Privacy · Terms · Disclosure · Sitemap