Daikin Heat Pump Error 81
⚡ Quick Answer: The Daikin heat pump error 81 indicates a compressor overload protection issue, often triggered by a faulty outlet water temperature thermistor. This ... ✅ DIY Fixable
What Does Error 81 Mean?
The Daikin heat pump error 81 indicates a compressor overload protection issue, often triggered by a faulty outlet water temperature thermistor. This error may cause the system to cease normal operation, display inaccurate temperature readings, and deliver incorrect water temperatures. Users may also notice unusual humming sounds from the unit as it struggles to operate correctly.
Common Symptoms:
- System may cease normal operation when detecting abnormal outlet water temperature
- Inaccurate temperature readings reported or displayed
- Heat pump may fail to deliver correct water temperature
Possible Causes
- Faulty or abnormal outlet water temperature thermistor (medium)
How to Fix Error 81
DIY Fix Check and restart the system
- Turn off the heat pump system and isolate power to ensure safety.
- Wait a few minutes then restore power to allow the system to reset.
- Observe whether the error 81 returns on restart.
Technician Only Inspect and replace outlet water temperature sensor
- Access the heat pump unit’s outlet water temperature thermistor location per service manual.
- Measure the thermistor’s resistance and compare to expected values at ambient temperature.
- If readings are out of specification, replace the thermistor sensor.
- Verify wiring harness and connector integrity between sensor and control board.
- Test system operation after repair.
Parts needed: Outlet water temperature thermistor, Associated wiring/connectors
- Error persists after system reset
- Repeated failures of temperature sensor or multiple error codes appear
- Unit fails to operate normally affecting heating performance
Next step
Choose the next step for 81
Confirm the diagnosis before ordering. An error code can identify the system involved, but it does not prove that a specific part has failed.
Most relevant component to inspect
Thermistor
Measures precise temperature changes and sends resistance feedback to the control board.
- Typical part-only price
- $15 - $35
- DIY difficulty
- Easy
- Estimated time
- 15-30 mins
Where can I find the model number?
Check the rating label around the door, lid, frame, rear panel, or inside the appliance cabinet. Use the complete model number, including suffixes.
Verify the complete model and part number on the retailer's compatibility page before ordering.
Other parts options
Check related components first; use model search as a fallback.
Wiring Harness
Connects controls, sensors, motors, and other electrical components inside the appliance.
Model-compatible Heat Pump parts
Enter the complete model number to browse compatible replacement parts. This is a model-based parts search, not a diagnosis that a specific component failed.
Affiliate disclosure: As an Amazon Associate I earn from qualifying purchases. We may earn a commission from other qualifying purchases or service requests made through links on this page, at no additional cost to you. Recommendations are based on repair relevance, not commission rate.
Optional routine care
Maintenance supplies
These products support cleaning or routine upkeep. They are separate from the possible repair components above and are not claimed to fix this error code or symptom.
Air Conditioner Fin Cleaner
For routine cleaning of accessible coil fins when permitted by the manufacturer. Disconnect power and follow product and appliance instructions.
Affiliate disclosure: As an Amazon Associate I earn from qualifying purchases. Recommendations are based on routine-care relevance, not commission rate.
Technical Specifications
| wattage | 3500W |
|---|---|
| component | Compressor |
| resistance | 5-10 ohms |
| part_number | DAIKIN 3D080A |
| voltage_rating | 240V AC |
Common Questions
What does 81 error mean on daikin heat pump?
Error 81 indicates a compressor overload protection issue due to a faulty outlet water temperature thermistor.
Can I fix daikin heat pump 81 error myself?
Yes, you can check and restart the system by turning it off, isolating power, and waiting a few minutes before restoring power.
How much does it cost to fix 81 error?
The estimated repair cost for error 81 ranges from ¥5,000 to ¥20,000, depending on parts and labor.
When should I call a technician for 81?
Call a technician if the error persists after a reset, if there are repeated failures of the temperature sensor, or if multiple error codes appear.
Sources & References
Data last verified: 2026-07-25
User Comments (0)
Share your experience or solution below.
Please login to post a comment.
Be the first to comment!