Goodman HVAC Error Code 15: How to Fix It

Medium 30-60 minutes Medium Severity Verified June 2026
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Error Code
15
Brand
Goodman
Product Type
hvac
Severity
Medium
DIY Difficulty
Medium
Estimated Fix Time
30-60 minutes
Error code 15 on your Goodman HVAC system indicates that the outdoor temperature sensor is open, meaning the sensor or its wiring has failed. This sensor helps your system regulate operation based on outdoor temperature, and an open circuit can cause improper heating or cooling. Follow this guide to diagnose and fix the issue.
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Tools You'll Need

How to Fix Error Code 15

  1. Turn Off Power to the Unit

    Always disconnect power before servicing HVAC equipment to prevent electric shock.

  2. Locate the Outdoor Temperature Sensor

  3. Inspect the Sensor and Wiring

  4. Test the Sensor with a Multimeter

    Be careful not to short the multimeter probes. Use insulated probes.

  5. Replace the Sensor if Faulty

  6. Check the Control Board

    Control board replacement is more advanced. Consider calling a professional if unsure.

  7. Restore Power and Test

Parts You May Need

Outdoor temperature sensor (thermistor)
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Control board
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Outdoor temperature sensor (thermistor)
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Control board
Check Price on Amazon
Outdoor temperature sensor (thermistor)
Check Price on Amazon
Control board
Check Price on Amazon
Outdoor temperature sensor (thermistor)
Check Price on Amazon
Control board
Check Price on Amazon
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When to Call a Professional

If you have replaced the sensor and the error persists, or if you are uncomfortable working with electrical components, call a licensed HVAC technician. Control board replacement is best left to professionals.

Frequently Asked Questions

What does error code 15 mean on a Goodman AC?
Error code 15 means the outdoor temperature sensor is open, indicating a broken sensor or wiring issue.
Can I bypass the outdoor temperature sensor?
No, bypassing the sensor can cause the system to operate incorrectly and may void warranty. Replace the faulty sensor.
How do I test a Goodman outdoor temp sensor?
Use a multimeter to measure resistance. At 77°F, it should read ~10,000 ohms. Infinite resistance means an open circuit.
Where is the outdoor temperature sensor on a Goodman unit?
It is usually mounted on the outdoor unit's coil or near the compressor. Check your manual for exact location.
Will error code 15 prevent my AC from running?
Yes, the system may not cool or heat properly until the sensor issue is fixed.

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