Goodman HVAC Error Code 20: How to Fix It
Medium 1-2 hours Medium Severity
Verified June 2026
- Error Code
- 20
- Brand
- Goodman
- Product Type
- hvac
- Severity
- Medium
- DIY Difficulty
- Medium
- Estimated Fix Time
- 1-2 hours
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Tools You'll Need
- Multimeter
- Screwdriver set
- Wrench (for tapping valve)
- Safety gloves and goggles
How to Fix Error Code 20
-
Safety First: Power Off the Unit
Always disconnect power before servicing to avoid electrical shock or injury. -
Inspect the Reversing Valve Solenoid
-
Test the Solenoid with a Multimeter
Ensure power is off before testing electrical components. -
Check for 24VAC at the Solenoid
Be cautious with live voltage. If unsure, call a professional. -
Inspect the Reversing Valve Body
Tapping too hard can damage the valve. Use light taps. -
Check the Control Board
Control board replacement requires careful handling. Consider professional help.
Parts You May Need
Reversing valve solenoid coil
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Reversing valve assembly
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Control board
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Reversing valve solenoid coil
Check Price on Amazon
Reversing valve assembly
Check Price on Amazon
Control board
Check Price on Amazon
Reversing valve solenoid coil
Check Price on Amazon
Reversing valve assembly
Check Price on Amazon
Control board
Check Price on Amazon
Reversing valve solenoid coil
Check Price on Amazon
Reversing valve assembly
Check Price on Amazon
Control board
Check Price on Amazon
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When to Call a Professional
If you've tested the solenoid, voltage, and valve but the error persists, or if you're uncomfortable working with live electricity or refrigerant lines (valve replacement requires brazing and refrigerant handling), call a licensed HVAC technician.Frequently Asked Questions
What does error code 20 mean on a Goodman HVAC?
Error code 20 indicates a reversing valve fault, meaning the system cannot properly switch between heating and cooling modes.
Can I drive my car with a stuck reversing valve?
You can operate the system, but it will be stuck in either heating or cooling mode. Use the emergency heat setting if needed, and repair promptly.
How much does it cost to fix error code 20?
DIY solenoid replacement costs $20-$50. Professional valve replacement can range from $400-$800 depending on refrigerant and labor.
Will resetting the system clear error code 20?
A temporary reset (turning power off for 5 minutes) may clear the code if it's a glitch, but if the valve fault persists, the error will return.
Is it safe to tap the reversing valve?
Light tapping can free a stuck valve, but excessive force can damage it. If tapping doesn't work, call a pro.