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Goodman Furnace Not Heating? 4 Common Causes (+ Fixes)

Goodman furnaces are great at keeping your home warm. However, even the most durable furnace can have problems that won’t let it heat. So, you’ve probably decided by now to find out why your Goodman furnace isn’t heating to avoid spending one more night in the cold.

Your Goodman furnace isn’t heating because of a clogged or damaged air filter, a faulty limit switch, or a defective blower motor. You can fix the problem by cleaning or replacing the filter, checking the limit switch to ensure it works, and repairing the blower motor.

This article will explain why your Goodman furnace isn’t heating and how to fix each problem. Keep reading if you want to restore heat to your home!

Clogged Air Filter

Always start with the easiest fix. When a Goodman furnace isn’t outputting heat to your home, check the filter. In most cases, it’s just a dirty filter.

The filter in your furnace plays a crucial role for the entire HVAC system. When air blows from the blower fan, it passes through the filter before entering the ductwork. The furnace filter removes dust, ensuring you don’t experience allergies or an asthma flare-up. 

Dirt from the air gradually builds up on the filter. Eventually, the build-up will start blocking a significant portion of the airflow. This means hot air can’t reach the vents even though the blower motor runs at maximum capacity.

How To Fix

The fix for this issue is pretty straightforward. Start by inspecting the furnace filter to see if it’s dirty. When you find a thick layer of dust on the filter, it’s time to clean it. Here’s how:

  1. Locate the compartment that houses the filter. It’s usually in the main compartment of the furnace setup. 
  2. Use the appropriate tools to remove the front-facing panel. 
  3. Take a closer look at the filter to see if it’s dirty. If you haven’t cleaned the filter in some time, it’ll likely have some dust on it. 
  4. Remove the filter from the furnace and clean it. Run it under water to get it completely clean.
  5. Wait for the filter to dry before placing it back into the furnace. 

Watch the video below if you need additional guidance when cleaning the filter:

Damaged Air Filter

While a dirty filter can block airflow and be the reason why your Goodman furnace isn’t heating, there are times when the filter is in a condition that calls for a replacement. When you take the filter out for cleaning, inspect it closely. 

Minor problems like a tiny crack can lead to both immediate and long-term issues. The issues it currently causes may not be notable, but not replacing the filter can lead to excessive amounts of dust and particles pushed into your house. 

Although many furnace filters are reusable, they eventually need to be replaced as they wear out.

How To Fix

You should determine if the filter needs to be replaced before getting a new one. You can do this while cleaning the furnace if you haven’t done the first step from the post. 

Check for deformed parts, cracks in the filter, or areas that have broken off. These may all indicate problems with the filter. If it is too dirty to clean due to sticky debris that doesn’t want to come off, it’s better to get a replacement filter.

Here’s how to replace the filter:

  1. Turn off the furnace.
  2. Remove the old filter from the furnace using the appropriate tools.
  3. Get a replacement filter with the same dimensions.
  4. Fit the new filter into the slot where the old one was placed. Make sure it clicks into place. 
  5. Fasten any screws that you removed previously. 

The following video explains how to replace a furnace filter in a few simple steps:

Faulty Limit Switch

There are a few different safety switches in your Goodman furnace. The limit switch is one of them. It’s a safety switch that regulates the power provided to the blower motor. The limit switch turns the blower off if it detects overheating to prevent permanent damage to the furnace.

Unfortunately, the limit switch can stop working. This is often due to a fault with the part itself, but it can also be caused by wiring issues. For example, the cable supplying the limit switch with power might be faulty.

How To Fix

First, let’s determine if the limit switch is the problem. Use a voltage meter to check if power is going to the switch. If the meter can’t detect any voltage, there’s a problem with the furnace power supply. 

But we don’t want to rule out the possibility that the switch is faulty either. If you have a spare switch, use it to troubleshoot the power supply. Even better, remove the switch and test it with a multimeter.

If you’re not sure how to replace the switch, check out the following video:

Defective Blower Motor

The blower assembly is responsible for pushing hot air from the furnace through the ductwork. The motor does this by rotating a large, sturdy fan. Like any other electric motor, the blower motor can run into various issues like misalignments and broken parts.

How To Fix

To check if there’s a problem with the blower assembly, power up the furnace. See if there’s any air being blown out of the vents. There should be at least some airflow coming from the vents, hot or otherwise.

If the blower isn’t kicking in, you won’t feel any air blowing through the vents. If that’s the case, take a closer look at the blower assembly. Here’s how to do it:

  1. Open up the furnace.
  2. Locate the blower motor and fan.
  3. Take a look at the wiring. See if there are any loose wires, as this can cause problems with the blower motor’s functionality.
  4. Check the fan. Look for signs of broken or chipped blades.

If you need to replace the blower assembly, start with the motor. You may be able to reuse the current fan if the new motor is compatible. 

Summary

Faulty or dirty filters, problems with the furnace limit switch, and a faulty blower motor can make your Goodman furnace stop heating. Address this problem as soon as it arises to avoid permanent damage to the furnace. Consider calling an HVAC technician if you don’t feel comfortable checking the inside of your furnace yourself.

If you’re having any other Goodman furnace problems, I recommend reading through our Complete Goodman Furnace Troubleshooting Guide.

Author

  • Alanna Greene

    Alanna is an avid traveler who lives in Michigan. In addition to writing for Temperature Master, he also sells crafts on Etsy and takes long walks through the forests near her home.

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