Goodman Furnace Not Lighting

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Quick answer
Confirm the symptom
Tools and prep
Step-by-step troubleshooting
Common causes table
Parts matching
When to call a pro
FAQ
Related guides

Quick answer

If your Goodman furnace won't light, first check the gas supply and thermostat settings. Then inspect the igniter and pilot light. If these don't resolve the issue, a faulty gas valve or blower motor may need professional attention.

Confirm the symptom

Furnace does not produce heat
No clicking sound when turning on thermostat
No visible flame in the burners
Thermostat is set to 'Heat' and temperature is lower than room temp

Tools and prep

Screwdriver (flathead and Phillips)
Flashlight
Multimeter (for voltage testing)
Gas leak detector or soapy water solution
Safety gloves and goggles
Service manual for your Goodman furnace model
Turn off power to the furnace at the circuit breaker
Ensure gas supply is on and accessible

Step-by-step troubleshooting

Check Thermostat Settings
Do: Verify the thermostat is set to 'Heat' and the desired temperature is higher than the room temperature.
Observe: Thermostat settings are correct but furnace still doesn't light.
Means: Issue is not with the thermostat settings.
Next: Check gas supply
Check Gas Supply
Do: Ensure the gas valve is fully open and there are no gas line issues.
Observe: Gas valve is open and gas is flowing to the furnace.
Means: Gas supply is not the issue.
Next: Inspect igniter or pilot light
Inspect Igniter or Pilot Light
Do: Look inside the furnace to see if the igniter is glowing or if the pilot light is lit.
Observe: Igniter is not glowing or pilot light is out.
Means: Igniter or pilot light may be faulty.
Next: Check for gas leak
Check for Gas Leak
Do: Use a gas leak detector or soapy water solution on gas connections to check for leaks.
Observe: Bubbles form at any connection, indicating a gas leak.
Means: Gas leak is present and needs immediate attention.
Next: Call a professional
Test Igniter with Multimeter
Do: Use a multimeter to test the igniter for proper voltage and continuity.
Observe: Multimeter shows no voltage or continuity.
Means: Igniter is faulty and needs replacement.
Next: Replace igniter
Inspect Blower Motor
Do: Check if the blower motor is running and producing airflow.
Observe: Blower motor is not running or airflow is weak.
Means: Blower motor may be faulty.
Next: Call a professional

Common causes

Cause	Likelihood	Difficulty	Part often needed
Faulty Igniter The igniter may not be receiving enough voltage to create a spark.	Common	Medium	Igniter
Gas Supply Issues The gas valve may be closed or there may be a blockage in the gas line.	Common	Easy	Gas valve
Thermostat Problems Incorrect thermostat settings or a faulty thermostat can prevent the furnace from lighting.	Sometimes	Easy	Thermostat
Gas Leak A gas leak can prevent the furnace from lighting due to safety mechanisms.	Rare	Hard	Gas line repair
Faulty Blower Motor A malfunctioning blower motor can prevent the furnace from operating properly.	Sometimes	Medium	Blower motor
Dirty or Clogged Filters Clogged air filters can restrict airflow and prevent the furnace from lighting.	Sometimes	Easy	Air filter
Faulty Gas Valve A faulty gas valve may not open to allow gas to the burners.	Sometimes	Hard	Gas valve

Parts matching

Common parts that may be needed for a Goodman furnace not lighting include:

Igniter
Gas valve
Thermostat
Air filter
Blower motor
Gas line repair kit

Always refer to your Goodman furnace service manual for specific part numbers and compatibility.

When to call a professional

If you detect a gas leak
If the igniter or gas valve is faulty and requires replacement
If the blower motor is not running and needs repair
If you are unsure about any step or lack the necessary tools
If the furnace still doesn't light after following all troubleshooting steps

FAQ

Why is my Goodman furnace not lighting even though the thermostat is set correctly?

This could be due to a faulty igniter, gas supply issues, or a problem with the furnace's internal components. Check the gas valve and igniter for any issues.

Can a dirty air filter cause my Goodman furnace not to light?

Yes, a dirty air filter can restrict airflow and prevent the furnace from lighting. Replace the air filter to see if this resolves the issue.

What should I do if I suspect a gas leak?

Immediately turn off the gas supply and call a professional HVAC technician. Do not attempt to repair the gas leak yourself.

How often should I replace the air filter in my Goodman furnace?

It is recommended to replace the air filter every 1-3 months, depending on usage and environmental factors.

Can I replace the igniter myself?

If you have the necessary tools and knowledge, you can replace the igniter. However, it is recommended to call a professional to ensure proper installation and safety.