Why Is My Furnace Blowing Cold Air?

If cold air is coming from your furnace vents, check the thermostat fan setting first. When the fan is set to ON, it keeps blowing air even when the furnace is not heating. If the fan is already set to AUTO, a dirty filter, ignition failure, or furnace shutdown could explain the lack of heat.

You can check the thermostat, filter, and power yourself. Problems inside the furnace need a technician.

Is It Normal for a Furnace to Blow Cold Air at First?

Cool air for a short time at startup is normal. Air sitting in your ductwork comes out before heated air reaches the rooms.

Start With These Safe Furnace Checks

Check the Thermostat Settings

Set your thermostat to HEAT and raise the temperature above the current room reading.

Look at the fan setting next. ON runs the blower between heating cycles. AUTO lets the furnace control when the blower runs.

Check the Furnace Filter

A filter packed with dust restricts airflow and can cause the furnace to overheat.

Replace a dirty, accessible filter with the correct type. Do not open the furnace to look for another cause.

Confirm the Furnace Has Power

Check the furnace switch and circuit breaker if accessible. If the breaker has tripped, reset it once.

If it trips again, leave it off and call for service.

Common Reasons a Furnace Can Blow Cold Air

The Heating Cycle Is Not Completing

Your thermostat calls for heat, but the furnace may stop heating before the room reaches the set temperature. The blower can continue running afterward.

A control or furnace safety device can interrupt the cycle.

Ignition or Combustion Problem

A gas furnace cannot heat your home unless its burners ignite and stay lit.

If ignition fails, the furnace may keep trying to start without producing heat. Leave burners and ignition parts to a technician.

Furnace Is Overheating and Shutting Down

Your furnace has a temperature limit that protects it from overheating. When it gets too hot, the heat shuts off while the blower may continue running.

Low airflow or another internal problem can cause this. Never bypass a safety control.

Blower or Control Problem

The blower moves heated air into your ductwork. A failed control or electrical component can cause it to run when the furnace is not producing heat.

What If the Furnace Keeps Starting and Stopping?

A furnace that runs briefly, shuts off, and starts again is short cycling. You may hear several starts without the house getting warm.

Getzschman's furnace repair work includes checking airflow, controls, and safety devices that can interrupt heating.

When Cold Air Means You Should Call for Furnace Repair

Give us a call if:

• Cold air continues with the fan on AUTO
• The thermostat setting is never reached
• The furnace shuts down repeatedly
• You hear banging, buzzing, or rattling
• An unusual smell develops
• Heat comes on briefly and then stops

Our heating services include repairs for furnaces and other home heating equipment throughout Omaha.

Furnace Safety Signs That Need Immediate Attention

If you smell gas, leave the house and contact your gas utility or emergency services from a safe location.

A carbon monoxide alarm means everyone needs to leave. Call emergency services and wait for clearance before returning.

For smoke, sparks, or strong electrical burning odors, stop using the furnace. Shut it off if safe. Leave and call emergency services if there is smoke or fire.

Can Furnace Maintenance Help With Cold-Air Problems?

During a furnace maintenance visit, we check airflow, controls, and parts that collect dirt during use. A tune-up can uncover wear or buildup, but a furnace that already has no heat needs repair.

If you have a heat pump instead of a furnace, cold air can come from a problem with the reversing valve, defrost cycle, or other components. Our heat pump services include diagnosing and repairing those problems.

Furnace Problems During an Omaha Winter

Nebraska's colder stretches can keep your furnace running for hours. If it cannot produce enough heat, rooms can get colder even with the thermostat turned up.

Have it checked before indoor temperatures drop further.

Schedule Furnace Repair in Omaha

Getzschman works on furnace problems throughout Omaha and nearby communities. If your furnace continues blowing cold air, schedule heating service to have it repaired.