It’s cold out and you want your house warm but the furnace is blowing cold air! Before you call in the experts, there are things you can look at to try and figure out what the problem is.

Troubleshooting Why Furnace is Blowing Cold Air When Heat is On

1. Check the thermostat. The thermostat should be set to “auto” rather than “on”. If the setting is set to “on” the fan in the furnace will run constantly even if the furnace isn’t heating the air. This may be why cool air might be coming out of the vents. The thermostat might not even be heating the air. The air coming out of the vents when the furnace is off will feel cool because it will be room temperature.
2. Dirty air filter. If the air filter is dirty, it will restrict the air flow into the furnace. This can also lead to the furnace overheating that can cause the safety control to shut the burners off. This is a safety measure that protects the furnace from overheating and causing damage so change the filters on a regular basis. If you’ve ruled out these possibilities, there might be other reasons. The next steps will require a heating repair company to determine what the problem is.
3. Pilot light or ignition problem. The ignition system might be having problems. If the furnace isn’t lighting the fuel, it can’t get your home warm either. First, you can try relighting the pilot light. If it stays on you’re good to go, Second, if it won’t light make sure there’s gas flowing into the furnace and make sure the gas switch valve in on. Check to see if the pilot light is dirty and is preventing gas from coming through. Thirdly, if it lights but won’t stay lit it might be a problem with the copper rod you see the flame hitting or the thermocouple. It will either need to be adjusted or replaced.
4. Inadequate supply of gas. If the gas supply is turned off or the gas line isn’t getting enough gas to the furnace, it can cause the furnace to turn off for safety reasons.
5. Major duct problems. If there are leaks or large holes in the air ducts it can make the furnace appear as if it’s not working properly. The cool air can be coming from the attic or crawlspace through the holes.
6. Clogged condensate. Newer furnaces that are more energy efficient have condensate drain lines that remove the water created as the furnace heats the home. There is a switch that’s activated to prevent the burners form lighting if this line becomes clogged.
7. Furnace size. The size of the furnace might be the problem. If it’s too small, it won’t have enough power to heat the whole house and will make it feel like the air is cooler.

Furnace Troubleshooting, Repairs & Replacement in the Las Vegas Valley, Summerlin, North LV & Henderson Nevada

Remember to change the air filters regularly. If you don’t change air filters it will cause the furnace to continue overheating and will damage the furnace’s heat exchanger leading to an expensive repair. Don’t ignore issues you’re having with your furnace. These small problems can be taken care of easily by contacting Air Supply Heating & Air Conditioning before they develop into major repairs or premature replacement. Call us today.