Goodman Furnace Blowing Cold Air – What Could Be Wrong? [6 Reasons Why]

Goodman furnaces are durable and efficient. Sometimes things go wrong, and your Goodman furnace stops blowing hot air. What should you do when this occurs? We asked the experts, and they provided us with answers.

Goodman furnaces have indicators. And these indicators have a code that you need to decode. Goodman furnaces have a troubleshooting guide that helps you detect what's wrong. Some common reasons why the furnace is blowing cold air could be due to the following: 

    1. An undersized furnace
    2. Dirty air filters
    3. A problem in the control panel
    4. Wrong thermostat setting
    5. Damaged/dirty flame sensor
    6. A poorly weatherproofed home

These problems are easy to rectify once established. Read on to see what you can do to ensure that your Goodman furnace continues to heat your home.

A Goodman air conditioning unit, Goodman Furnace Blowing Cold Air - What Could Be Wrong? [6 Reasons Why]

Why Your Goodman Furnace Is Blowing Cold Air

Troubleshoot appliances to understand what is causing them to malfunction. The same applies to Goodman furnaces. Check the following before calling a professional to diagnose your furnace.

Repairing and cleaning the inside of a furnace

1. Undersized Furnace

Goodman furnaces come in different sizes. The furnace installed in your home might not heat the whole house properly. An undersized furnace will run overtime to heat a large home. It will hike your energy bills.

Solution: Before purchasing and installing a furnace, consult a professional to know which size will heat the home properly. You should consider the size of the space that needs to be heated. Ensure that you understand the heating factor of each room.

Check out this Goodman furnace on Amazon

2. Dirty Air Filters

Air filters ensure that no debris or dirt gets into the air getting into the home. Clogged air filters won't allow air to pass through to the ductwork.

Solution: Look for the filter's location, remove it, and clean it. A lasting solution is to replace the filter with a new one.

3. Control Panel Problem

Power surges, age, or loose wiring, could make the control panel in a Goodman furnace malfunction. A damaged control panel will tamper with the temperature readings. The false readings might make you think you are heating your home.

Solution: The control panels use electricity to run. Therefore, ensure that you connect the furnace to an independent socket. Call a professional to rectify this issue, and don't tamper with any wiring.

4. Wrong Thermostat Settings

When the thermostat has the wrong settings, the furnace will heat the space according to those settings. The data sent by the thermostat might be erroneous. The erroneous data might cause the furnace not to heat.

Solution: Check the thermostats to see if they read 'Cool' or 'Heat'. Proceed to set the desired temperature for the furnace to heat your home.

5. Damaged Or Dirty Flame Sensor

The flame sensor needs to be clean from any dirt to kindle properly. When the flame sensor is dirty, it won't light. Check whether the sensor is damaged or the gas isn't running to the burners.

Solution: Turn off the power supply to check if the flame sensor is dirty. If the sensor is damaged, have a professional repair or replace it. Also, check to see if the gas supply is working.

Have a look at this flame sensor on Amazon

6. Poorly Weatherproofed Homes

Your home could be losing heat via open windows and doors, poorly insulated walls, ceilings, and basements. Around the ductwork, warm air could be escaping as well.

Solution: Ensure that there are no cold drafts in the home. Drafts might make you think your furnace is blowing cold air. Insulate your home properly, including the basement. Close the registers at the bottom of your rooms, too.

How To Ignite A Goodman Furnace

Homeowners should be aware of how their furnace ignites. It's easy to pinpoint where the problem lies when your furnace doesn't come on.

Start by turning on the power supply. When the power is on, the furnace understands the need for heat by having the combustion blower come on.

The switches will alert that the combustion blower is running and record the negative pressure in the combustion blower.

Next, the ignition should go on immediately. You hear a click after 15 to 20 seconds. The click is the gas channel allowing gas to flow, and the flames will come on.

Once the flame sensor registers the presence of a flame, wait for a little while, and the main blower will come on. Finally, the heated air flows into the ductwork.

Here's a short video to demonstrate the sequence.

Does Goodman Make Good Furnaces

Yes, they do! Reviews have shown that they are among the most preferred furnaces in the market. Homeowners and engineers tend to favor Goodman furnaces. Here are some of the reasons why.

  1. You will get a worthy Goodman furnace for your money.
  2. Goodman furnaces are energy efficient.
  3. These furnaces have better warranties than most furnaces on the market.

Most Popular Goodman Furnace

The Goodman furnaces are manufactured in America by the Daikin Group. It is based in Houston and was founded in 1975. The Daikin Group is the largest manufacturer of HVAC systems.

The star furnace of the company is the GMVM97 Goodman Furnace. It's a gas furnace with 98% AFUE performance. Homeowners like the furnace because it has multi-position installation. 

What Is The Lifespan Of A Goodman Furnace

Goodman furnaces are known to last from 15 to 30 years. To have the best of a Goodman furnace, have a professional install it. You should endeavor to maintain it well!

These furnaces have warranties that last for ten years. Experts advise homeowners to start shopping for a new furnace after 15 years of usage.

Is There Use For An Old Furnace

Yes, you might find a use for an old furnace by selling to dealers for spare parts. You can save some money by replacing your furnace with a used one. Although, there are some factors to consider.

It isn't every used furnace that is broken or damaged. Some homeowners want to replace old models with newer models. The best place to buy a used furnace is from a commercial seller. To get some profit and entice customers, commercial sellers refurbish used furnaces.

In case you wish to buy from any other seller, these are the questions to ask:

  • How old is the furnace?
  • Why is it being sold?
  • How often was it maintained?
  • What's the brand?
  • What is the type of fuel (for furnaces that use it)?
  • Does the warranty still cover it?
  • How about its performance?

Not every seller will be truthful. Therefore, inspect the furnace and use your discretion before purchase.

If you are nervous about any details, consider buying from wholesalers. They often have discounted rates!

How To Read Goodman Error Codes

Technology allows homeowners to understand when their furnaces need attention. Before a total shut-off occurs, there are some warning codes you'll notice on a Goodman furnace.

Here is a key to decode the light indicator on a Goodman furnace. 

  • One flash: The system locked due to exceeded retries to kindle. The furnace will automatically reboot itself.
  • Two flashes: The pressure switch is stuck while closed. Replace the switch or repair it.
  • Three flashes: The pressure switch, in this case, is stuck open. Check for loose wiring.
  • Four flashes: Open high limit. Clean the filters because the furnace might be working overtime.
  • Five flashes: The furnace senses a flame where there isn't any. Check for a leaky gas valve or faulty flame sensor.
  • Six flashes: Faulty power supply. Check for any burnt fuses or voltage issues.
  • Seven flashes: This is a low flame signal. There could be little gas pressure in the furnace so adjust it.
  • Eight flashes: A faulty ignitor could be the cause. Check to see if the ignitor is properly attached.
  • Nine flashes: High stage pressure in the furnace. Check for a blocked pressure hole.
  • Steady on light: The furnace is working correctly.
  • Light off: there's a control failure. So, you'll need to change the control board.
  • Rapid flashes: An issue with the wiring. Invite an HVAC technician to assist.

The diagnostic chart on a Goodman furnace isn't for decoration. Familiarize yourself with the error codes to avoid irreparable damage to your Goodman furnace. Prevention is better than cure!

You can find these codes on the inside of the door panel. Here is a video on what to expect in a Goodman furnace.


A Goodman air conditioning unit

Goodman furnaces are durable and can serve up to 30 years when properly maintained. Troubleshoot the furnace if it's blowing cold air.

The Goodman furnace has an easy to comprehend manual. Invite an HVAC technician for a thorough diagnostic of the furnace regularly. It'll save you time and money in the long run.

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