Why is my Lennox furnace blowing cold air?
Your furnace may be blowing cold air because the filter is too dirty. A dirty air filter blocks airflow over the furnace’s heat exchanger, causing it to overheat. When overheating, your furnace can trip a high limit switch, causing the furnace burners to shut off so that the heat exchanger does not crack.
Why is my furnace blowing cool air?
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 is cool air coming from the vents even though heat is on?
Clogged air filters could be causing cold air to blow out of your vents. A dirty air filter can block airflow over your furnace’s heat exchanger, which can cause it to overheat.
How do you reset a furnace that blows cold air?
Pilot Light Is Out
- Turn off power to the furnace.
- Locate the pilot light assembly and turn the reset switch to OFF.
- Wait 10 to 15 minutes to allow any escaped gas to clear the area.
- Turn the reset switch to PILOT. …
- Once the pilot is lit, turn the switch to ON.
- Restore power to the furnace.
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.
Why is my furnace running but no heat?
Dirty filters are the most common cause of furnace problems. Dust and dirt restrict airflow—and if the filter gets too clogged, the heat exchanger will overheat and shut off too quickly, and your house won’t warm up. If the blower is running but no heat is coming out, replace the filter.
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.
How can you tell where cold air is coming from?
Start by checking your attic, basement and crawl spaces for any cracks, gaps and openings where cold air may be coming through. You can also try a smoke test. On a windy day, shut all windows and doors, and turn off all appliances. Then hold a lit incense stick next to potential air leakage spots.
How do you unclog a heater core?
Quote from the video:
Quote from Youtube video: I'm going to show you how you can take off the hoses that go to the heater core attach this to the water hose blast it out and within a few seconds your heater core will be unclogged.
