Fujitsu Mini-Split Error Code 38: How to Fix It

Medium 30-60 minutes Medium Severity Verified June 2026
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Error Code
38
Brand
Fujitsu
Product Type
mini_split
Severity
Medium
DIY Difficulty
Medium
Estimated Fix Time
30-60 minutes
Error code 38 on a Fujitsu mini-split indicates a fault with the outdoor unit's liquid pipe thermistor. This sensor monitors refrigerant temperature; when faulty, the system may stop cooling or heating. The fix involves testing and replacing the thermistor.
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Tools You'll Need

How to Fix Error Code 38

  1. Turn Off Power

    Always disconnect power before working on the unit.

  2. Locate the Liquid Pipe Thermistor

    Be careful not to touch sharp edges or electrical components.

  3. Visually Inspect the Thermistor

  4. Test the Thermistor with a Multimeter

    Ensure multimeter leads do not touch each other.

  5. Replace the Faulty Thermistor

    Apply thermal paste or use a clamp that ensures good contact with the pipe.

  6. Reassemble and Test

Parts You May Need

Liquid pipe thermistor
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Liquid pipe thermistor
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Liquid pipe thermistor
Check Price on Amazon
Liquid pipe thermistor
Check Price on Amazon
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When to Call a Professional

If you are uncomfortable working with electrical components, or if the error persists after replacing the thermistor, call a certified HVAC technician. Also, if you need to handle refrigerant lines, professional help is required.

Frequently Asked Questions

What does error code 38 mean on a Fujitsu mini-split?
Error code 38 indicates a fault with the outdoor unit's liquid pipe thermistor, which measures refrigerant temperature. It's a sensor issue, not a refrigerant leak.
Can I fix Fujitsu error 38 myself?
Yes, if you have basic electrical skills and a multimeter. You need to test and replace the thermistor. Always turn off power first.
Where is the liquid pipe thermistor located?
It's inside the outdoor unit, attached to the liquid line (smaller copper pipe) near the service valves. You'll need to remove the service panel to access it.
What should the resistance of the liquid pipe thermistor be?
At 77°F (25°C), it should read about 10k ohms. If it's open or shorted, replace it.
How much does it cost to fix error code 38?
DIY: $10-$20 for a generic thermistor. Professional repair: $150-$300 including service call and part.

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