Few things are more frustrating during the winter months than turning on your furnace, only to feel cold air coming from the vents instead of the warmth you expect. If your furnace is blowing cold air, there could be several reasons behind the problem, ranging from simple fixes to more serious issues requiring professional attention. LV Heating & Cooling would like to walk you through the potential causes of cold air from your furnace and what you can do to resolve the problem.
Check Thermostat Settings
Before diving into complex issues, start by checking your thermostat. Sometimes, the problem is as simple as incorrect settings.
• Ensure the Thermostat Is Set to “Heat”
• Check the Temperature Setting
• Check if the Thermostat Batteries Need Replacement
Check if Furnace is Overheating
If your furnace is blowing cold air, it could be a sign that it’s overheating and automatically shutting down to prevent damage. Most furnaces have a safety feature that turns off the burner if the system gets too hot.
• Dirty Air Filters: One of the most common causes of furnace overheating is a dirty or clogged air filter. When the filter is blocked, airflow is restricted, causing the furnace to work harder, which can lead to overheating. Check and replace the air filter if it’s dirty.
• Blocked Vents or Ducts: A blocked vents or ductwork can also cause poor airflow, leading to overheating. Ensure that no furniture or items are blocking the vents in your home and that the ducts are clear of obstructions.
Inspect Pilot Light or Ignition System
If you have a gas furnace, the issue might lie with the pilot light or ignition system.
• Pilot Light is Out (Older Systems): If your furnace uses a standing pilot light, check to see if it has gone out. If the pilot light is out, the furnace won’t ignite the gas needed to produce warm air. You can try relighting it by following the manufacturer’s instructions. If the pilot light keeps going out, there may be a problem with the thermocouple, which senses whether the pilot light is lit and controls the gas flow.
• Electronic Ignition Issues (Newer Systems): Many modern furnaces use an electronic ignition system, such as a hot surface igniter. If the igniter is cracked or worn out, it won’t be able to ignite the gas, resulting in cold air. If this is the case, you’ll need a professional technician to replace the igniter.
<2>Check Gas Supply of Furnace
A lack of gas supply can prevent your furnace from producing heat. If your furnace is blowing cold air, check the following:
• Is the Gas Valve On: Ensure that the gas valve leading to the furnace is fully open. If it’s partially closed or accidentally turned off, the furnace won’t have enough gas to produce heat.
• Check for Gas Supply Issues: If you’ve verified that the gas valve is open but still aren’t getting heat, there could be a larger issue with your gas supply. If you suspect a gas leak or other gas-related issue, turn off the furnace immediately and contact your gas company or a professional HVAC technician for assistance.
Inspect Furnace Flame Sensor
The flame sensor is a safety device that ensures the gas valve is only open when a flame is present. If the flame sensor is dirty or faulty, it may shut off the gas valve prematurely, causing the furnace to blow cold air. Over time, the flame sensor can become covered in soot or carbon buildup, which prevents it from detecting the flame. If you’re comfortable doing so, you can turn off the furnace and carefully clean the flame sensor with a soft cloth or fine sandpaper. If cleaning doesn’t fix the problem, the sensor may need to be replaced by a professional.
When to Call a Professional Heating Contractor
While some furnace problems can be addressed with simple fixes, others may require professional diagnosis and repair. If your furnace continues to blow cold air after checking the thermostat, air filter, pilot light, and gas supply, or if you suspect a more serious issue, it’s best to call an HVAC technician. A professional will be able to identify the root cause of the problem and make the necessary repairs to restore your home’s heating.
Central Forced Air Furnace Heating Inspections, Tune Ups, Repair, Replacement & More in Summerlin, North LV, Henderson, Enterprise, Paradise, Spring Valley, Sunrise Manor & Greater Las Vegas, NV
If your furnace is blowing and you need help restoring heat to your home, contact LV Heating & Cooling and schedule our services today.
