If your furnace is blowing cold air in your home, this is a sign of an issue with the flame detector, gas supply, air filter, pilot light, or condensate lines. Many of these issues are able to be easily solved on your own by sanitizing or replacing components in the gas furnace.

Why does my furnace blow cold air when it first comes on?

The furnace needs time to warm up, or your thermostat is on the wrong setting. If the furnace kicks on and immediately sends out cold air, give it a minute or two. Heaters need a bit of time to warm up, as it must push out cold air from the vents before sending out hot air.

Why does my furnace blow out cold air before warm air?





The most common cause of a furnace that blows cold air before warming up is a faulty fan limit switch. Your furnace has a fan that pulls in cold air and pushes out warm air. After the heat exchanger (which is the part that warms the air) has heated up, the fan limit switch signals the fan to switch on.

How do you fix a furnace that blows cold air?

If you have a dirty filter, replacing the filter typically stops cold air from blowing. Find the filter compartment on your furnace, remove its access door if applicable. Slide out and dispose of the old filter. Insert a new one of the same dimensions into the filter compartment.

Why is cold air coming out of my vents when the heat is on in my car?

Low Coolant Level



The coolant (usually a mixture of water and antifreeze) in your engine doesn’t just work to keep the engine from overheating: It’s also the source of heat supporting the heating system. If there isn’t enough coolant in your system, the heater core will blow cold air into your car.

Why does my heat feel like cold air?

Your body temperature is around 98.6°F (everyone’s body temperature is slightly different, but that’s the average). Since heat pumps produce air that’s below that, it can feel cold to you.

Why is my furnace not blowing out hot air?





Troubleshooting Furnaces Not Blowing Hot Air



Check batteries of your thermostat and replace the drained or faulty one. Check the fan settings on your thermostat if they are set to “auto” instead of “on”. Make sure someone else has not set your thermostat to a lower temperature.

How do I stop my vents from getting cold air?

How to Keep Cold Air Out of Your Vents

  1. Install insulation. Poor insulation causes rapid cooling of the air as it moves through your home. …
  2. Check connections. Over time, the connections in your ductwork can come loose. …
  3. Update your HVAC. Older HVAC systems are less efficient and require more upkeep than modern models.


How do I know if my furnace gas valve is bad?

Here are some signs that indicate your furnace has a bad gas valve.

  1. A Gas Leak. This is a major indicator that something could be wrong with the gas valve in your furnace. …
  2. A Total Shutdown of the Furnace. …
  3. A Flooded Furnace. …
  4. Get Expert Services.



How much does it cost to replace gas valve on furnace?

$300 to $750 dollars

Average Cost To Replace the Gas Valve on Your Furnace? According to sites like Home Advisor and CostEstimates.com, replacing the gas valve on your furnace can cost anywhere from $300 to $750 dollars. This includes the part itself and the services of an HVAC professional.

How do you reset the gas valve on a furnace?



If you turned off the power, turn it back on. Then, turn on the main gas supply and press the reset button. Hold it in for about 30 seconds, release it and adjust the main thermostat to its former setting.

How long should a gas valve last?

Gas Valves are routinely checked for 100,000 cycles and are used in equipment that have approximately 15 years life expectancy.

Can I change the gas valve on my furnace?

Quote from the video:
Quote from Youtube video: We simply unscrew the gas valve. To replace the gas valve. We notice this one says propane gas.

Where is the flame sensor in my furnace?

A furnace flame sensor is a very basic part of your furnace. It’s located on the burner assembly and is just a thin metallic rod. It’s usually bent, and it sits just in front of the pilot flame inside the furnace.