It’s the heart of winter and even here in Atlanta, we have some chilly nights. Luckily our home furnace keeps us warm and toasty. But what if you raise the heat to find your home heater blows cold air? We’ll review some common reasons why you feel your Goodman furnace blowing cold air from a dirty flame sensor to a clogged air filter.

How to Troubleshoot a
Goodman Furnace Blowing Cold Air

Why is my Goodman furnace running but no heat? Troubleshooting this question can lead you down time-consuming roads with numerous possibilities. We’ll narrow down the most common causes for a Goodman furnace blowing cold air to warm your winter nights again.

#1: Incorrect Thermostat Setting

When you ask, “Why is my heat blowing cold?” a more accurate question can be “Who touched the thermostat?” Before you open up your furnace, check your thermostat to make sure it’s still switched to AUTO. This setting means the fan will only blow when the furnace is providing hot air. If it was mistakenly switched to ON, the furnace fan will run continuously but provide no heated air.

Goodman furnace blowing cold air

Photo Credit: Amazon


#2: Clogged Air Filter

When you find your furnace not blowing hot air a common cause with a simple fix can be a clogged air filter. These filters screen out dust and other particles before the furnace’s heated air is blown throughout the house. Consequently, they can get clogged over time, making your furnace run longer until it overheats. Once this happens, the furnace will only blow cold air.

We recommend changing your furnace air filter 3-4 times per year. If you find your Goodman furnace blowing cold air and can’t remember your last filter change, try replacing the filter to solve the problem.

#3: Dirty Flame Sensor

Most pilotless furnaces use a flame sensor to keep the unit’s flame burning once it starts. However, these sensors can easily get covered with dirt and grime, prohibiting them from monitoring the furnace flame. This means your furnace burner will keep turning off and the house won’t receive hot air. A dirty flame sensor will need to be cleaned or replaced if damaged.


#4: Dusty Oil or Gas Burner

When a Goodman furnace blows cold air at night or when you try to turn it on, it can also be due to a dirty oil or gas burner. Over time, these burners can get covered with a layer of dust, cutting off the supply of oxygen that they need to light.

You can avoid dusty burners with regular furnace maintenance by a home heating professional. If you find dusty burners when you notice your Goodman furnace blowing cold air, a professional cleaning can solve the problem.

#5: Control Panel Glitch

A convenient as computerization can be, sometimes technology can just add to the troubleshooting list. Many modern furnaces have a computerized control panel to process thermostat signals. These computerized furnace controls can encounter a glitch, prohibiting the furnace from responding to a signal or command.

To test your furnace control panel, turn the furnace power switch off. After waiting a few minutes, turn it back on to see if that resets the control panel. If the furnace still blows cold air you may need to seek professional service.

Whether you’re troubleshooting a furnace making loud noises or a Goodman furnace blowing cold air, even the best DIY owners can require help. Call Dependable Heating and Air for the best furnace repair near Atlanta and a return to warm winter nights.