Gas Furnace Blowing Cold Air? It's Probably One Of These Easy-To-Fix Problems

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Up until a few years ago, I would get sick whenever the seasons would change. I couldn't figure it out, until one day when an HVAC contractor pointed out my filthy air filters. I am embarrassed to say it, but I didn't know that air filters had to be changed at all, and all of that filthy air was circulating through my home. After I changed the air filters and started to take care of my HVAC system, my allergies got a lot better and I didn't feel as sick. I want other people to understand the massive benefits of taking care of their HVAC systems, so I put up this website.


Gas Furnace Blowing Cold Air? It's Probably One Of These Easy-To-Fix Problems

23 August 2016
 Categories: , Articles

If your home feels cold and drafty in the winter, even after turning on the heat, you may think that your gas furnace is damaged or broken. Sometimes, furnaces blow cold air because they're just plain dirty. The air vents in the ceiling and/or flooring can also have problems that prevent warm air from entering your home's rooms. Instead of spending this winter chilly and uncomfortable, check your heating system for these easy-to-fix problems.

Clean the Furnace's Blower System

A dirty air filter is one of the most common reasons furnaces slow down in performance and don't work as efficiently as they should. The first thing you want to do is change the air filter to see if it's the reason for your poorly performing furnace. If your furnace still doesn't blow warm air after a reasonable amount of time passes, turn off the heating system's electrical power and gas supply, then check the parts inside the appliance for issues. Your dirty air filter may have allowed contaminants to pass through to the blower and the parts it protects.

The blower cage usually sits in the lower half of the furnace, just behind the air filter. A small motor sits in the center of the blower and is surrounded by long fan blades that look similar to a hamster wheel. The blades turn or rotate in order to circulate warm air through the furnace. Dirt can build up on the fan blades and cause the motor to cycle off and on, run nonstop or eventually overheat.

The first thing you might do is read over your furnace's operating manual to find out how to remove the cage from its compartment. Some blowers use various wires and parts to connect to their furnaces. You don't want to accidentally crack or rip the wires. After you safely remove the blower from the furnace, obtain a small toothbrush, bucket of clear water with two cleaning rags, and small container of household oil.

Follow the steps below:

  1. Use your toothbrush to remove any dust and dirt from the fan blades. You may need to dampen your toothbrush to clean stubborn areas of debris.
  2. Wet a cleaning rag with water, then gently wipe down the blower cage. Try to remove as much dirt and dust as possible from the interior and exterior sides of the cage.
  3. Dry the damp blower cage with a clean rag.
  4. Locate the oil ports on the motor. The ports are labeled, so this shouldn't be a difficult task. Fill the ports with at least three drops of oil. If oil oozes out of the ports, remove it right away.

You can also use a vacuum to suck out any debris that coats inaccessible areas of the fan blades and blower cage. Place the blower cage back into the furnace, then reconnect its wiring. Turn on the heating system and allow it to cycle on and off as normal. If the home warms up properly, you solved the issue. If the furnace still blows out cold air, you can check one more thing: your air registers.

Clean Your Air Vents

Air vents allow warm air to circulate into the home. Sometimes, dust and other debris can build up on the vents' grates, or covers, and block airflow. You can solve this issue by wiping down the grates and vacuuming out the vents. Be sure to turn off the furnace during the cleaning to avoid getting debris in your face and respiratory system. Also, obtain one large bucket of soapy water and several cleaning rags. 

You'll need a screwdriver to unscrew the vents and goggles to protect your eyes. If your vents are found on the ceiling, you can use a wide-based ladder to access them. Place each vent inside the water to soak for at least 10-15 minutes. The time may vary for this step. Remove the vents from the water, then dry them thoroughly. Vacuum out the vents to remove debris you can't see. Replace the vents, then return power and gas to your heating system.

If the home feels warm and comfortable, you completed your repairs. If the home remains cold and drafty, contact a heating contractor like Custom Comfort for services. There may be other issues to fix.