Goodman HVAC Error Code 5: How to Fix It

Easy 15-30 minutes Medium Severity Verified June 2026
Error Code
5
Brand
Goodman
Product Type
hvac
Severity
Medium
DIY Difficulty
Easy
Estimated Fix Time
15-30 minutes
Error code 5 on your Goodman furnace indicates a weak flame sensor signal. This usually means the flame sensor rod is dirty or corroded and needs cleaning. A clean flame sensor ensures your furnace runs safely and efficiently.
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Tools You'll Need

How to Fix Error Code 5

  1. Turn Off Power to the Furnace

    Always disconnect power before servicing any electrical component. Failure to do so can result in electric shock or injury.
  2. Locate the Flame Sensor

  3. Remove the Flame Sensor

    Be careful not to damage the ceramic insulator on the sensor.
  4. Clean the Flame Sensor Rod

    Do not use any liquid cleaners or chemicals on the sensor.
  5. Reinstall the Flame Sensor

  6. Restore Power and Test

    If you smell gas or hear unusual noises, turn off the furnace and call a professional immediately.

Parts You May Need

Flame sensor rod
Check Price on Amazon
Flame sensor rod
Check Price on Amazon
Flame sensor rod
Check Price on Amazon
Flame sensor rod
Check Price on Amazon
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When to Call a Professional

If cleaning the flame sensor does not clear the error code, the sensor may be faulty and need replacement. In some cases, the furnace control board may be defective. If you are uncomfortable working with gas or electrical components, or if the problem persists after cleaning, contact a qualified HVAC technician.

Frequently Asked Questions

What does error code 5 mean on a Goodman furnace?
Error code 5 indicates a weak flame sense signal. It usually means the flame sensor rod is dirty or corroded and needs cleaning.
How do I clean a Goodman furnace flame sensor?
Turn off power, remove the sensor, gently scrub the metal rod with fine-grit sandpaper or a soft abrasive pad, wipe clean, and reinstall.
Can a dirty flame sensor cause a furnace not to start?
Yes. If the flame sensor doesn't detect a flame, the furnace may shut off after a few seconds to prevent gas buildup.
How often should I clean the flame sensor on my Goodman furnace?
It's a good idea to clean it annually as part of routine furnace maintenance.
Is it safe to clean the flame sensor myself?
Yes, as long as you turn off power to the furnace. It's a simple DIY task for most homeowners.