In the wintertime, you turn to your furnace to heat your house and maintain indoor comfort. Returning home or waking up to a furnace that’s just blowing cold air is an unpleasant situation. A malfunctioning heater can also lead to frozen and burst pipes. Some furnace problems are safety risks, too, so it’s important to take action as soon as you notice an issue. Here are seven possible reasons why your Richmond Hills furnace is blowing cold air and some tips on what you should do in each situation.
1. Thermostat Problem or Improper Thermostat Setting
Make sure your thermostat is set to the heating function. Verify that the fan is set to auto instead of “on.” A fan set to “on” will blow air all the time, even when there’s no heating cycle taking place.
2. Dirty Air Filter
Dirty air filters are one of the top reasons why furnaces blow cold air. When the filter is clogged, the heated air can’t pass through it. The hot air will be trapped in the combustion chamber. This could cause the heat exchanger to overheat and crack. Be sure to check the furnace filter once a month. Ideally, check it on the same day of each month, such as the first Friday. If it’s dirty after one month of use, replace it. Avoid going longer than three months between filter changes.
3. Pilot Light Went Out
Older furnaces have pilot lights that must be on at all times. If the pilot light goes out, the heater can’t burn fuel. Use the owner’s manual to reset the pilot light. If you’re not sure how to do this, or you’re not comfortable doing it yourself, a skilled furnace technician can handle this task for you.
4. Blocked Condensate Line
If you have a newer, high-efficiency furnace that’s blowing cold air, a clogged condensate line may be the cause of the problem. The condensate line drains moisture out of the furnace. For safety reasons, the heater will shut down if the condensate line becomes blocked. The backup of water triggers the furnace’s overflow kill switch. The air handler might continue running, but the furnace itself will power off. Blockages in the condensate line can be caused by rodents, dirt, dust, algae, or other debris. Routine furnace maintenance prevents this from happening.
5. Cracked Heat Exchanger
Operating the furnace with a dirty filter or skipping maintenance could cause the heat exchanger to overheat. Heat exchangers can also overheat if there’s a problem with the thermocouple, capacitor, or other critical parts. An overheated heat exchanger will crack. Once it cracks, it can’t do its job of heating the air blown across it. Most heat exchangers release an unusual odor when they crack. If you smell a chemical, metallic, or formaldehyde stench, it could be due to a crack in the heat exchanger. This is a serious problem that requires prompt repair.
6. Gas Supply Problem
An issue with the gas supply valve could cause your furnace to blow cold air. If there’s not a steady stream of gas for the furnace to burn, it can’t provide consistent heat. Gas supply valve problems require professional attention from our certified technicians. A malfunctioning gas valve could also cause a gas leak in your residence. If you smell the odor of natural gas, immediately exit your house and call for emergency repairs.
7. Burner Problem
Look into your furnace to see the burner’s flame and condition. If the flame is orange or yellow, the burner could be dirty. A flickering flame also suggests a problem with the combustion chamber. Soot or ash buildup on the furnace burners interferes with their ability to heat the air passing over them. This could cause the furnace to blow cold air through your vents. This buildup suggests that the fuel isn’t burning properly. Your equipment may need maintenance or repair in order to restore proper burner functioning.
Galbreath & Sons, Inc. is Richmond Hill’s trusted provider of furnace repairs. Homeowners in the area also turn to us for reliable heating and cooling maintenance and installation. Our solar, indoor air quality, and duct sealing services can lower your utility bills, improve your indoor comfort, and enhance your well-being. For more details about why your home’s furnace is blowing cold air or to schedule a furnace repair in Richmond Hill or the surrounding area.