Few things are more frustrating in the middle of winter than turning on your furnace and feeling cold air blowing from your vents. While this can be alarming, it is not always a sign of a major failure. In many cases, there is a simple reason behind it and is an easy fix. LV Heating & Cooling will share why your furnace might be blowing cold air and what you can do about it.
Furnace Has Not Warmed Up Yet
When a furnace first turns on, it often blows cool air for the first minute or two. This is simply the system clearing out cold air from the ducts before warm air arrives. Give it a few minutes to reach operating temperature.
Pilot Light or Ignition Problem
If you have a gas furnace, a malfunctioning pilot light or electronic igniter can prevent the burners from lighting, leaving only cold air blowing. For older systems, check if the pilot light is out and relight it following the manufacturer’s instructions. For newer furnaces with electronic ignition, call an HVAC technician as igniters and flame sensors are delicate and best handled by a pro.
Overheating Due to a Dirty Air Filter
A clogged air filter can restrict airflow, causing the furnace to overheat and shut off the burners as a safety precaution while the blower keeps running and pushing out cold air. Check and replace your air filter regularly every 1 to 3 months during the heating season.
Problems With the Limit Switch
The limit switch monitors the furnace temperature and prevents overheating. If it is faulty or tripped, it can shut off the burners prematurely, resulting in cool air from the vents. This is a safety device that should only be inspected and repaired by a licensed HVAC technician.
Air Duct Leaks
If your ductwork has leaks or gaps, warm air can escape into unconditioned spaces like the attic or crawlspace. By the time the air reaches your vents, it may feel cool. Have your ductwork professionally inspected and sealed to improve efficiency and comfort.
Fuel Supply Issues
For gas furnaces, a problem with the gas line or a closed valve can prevent the burners from igniting. If you suspect a gas leak, are smelling gas or hearing a hissing sound, evacuate your home immediately and call your utility company or emergency services.
When to Call a Professional
If you have checked the basics, thermostat settings, filter, and pilot light and your furnace still blows cold air, it’s time to call an HVAC technician. Issues like faulty igniters, damaged limit switches, or duct leaks require professional diagnosis and repair.
Heating Inspections, Tune Ups, Repair, Replacement & More in Summerlin, North LV, Henderson, Enterprise, Paradise, Spring Valley, Sunrise Manor & Greater Las Vegas, NV
A furnace blowing cold air does not always mean disaster. In many cases, it is a simple issue like a thermostat setting or clogged filter. But if the problem persists, a prompt inspection by a professional can prevent further damage and restore warm, comfortable air to your home. Contact LV Heating & Cooling today if your furnace is blowing cold air or having any other problems this winter.
