Daikin Altherma fault E6-00

Outdoor unit: compressor startup defect

Heat pump

What it means

The motor rotor does NOT rotate when the compressor is energized.

Likely causes

  1. Faulty discharge pipe thermistor or connector fault
  2. Closed stop valve in the refrigerant circuit
  3. Clogged refrigerant circuit
  4. Refrigerant overcharge or shortage
  5. Non-condensables and/or humidity in the refrigerant circuit
  6. Faulty compressor or miswiring of the compressor power supply cable
  7. Faulty main PCB
  8. Faulty inverter PCB
  9. Faulty 4-way valve
  10. Faulty expansion valve
  11. Faulty refrigerant pressure sensor
  12. Poor water flow through high pressure side plate heat exchanger
  13. Incorrect refrigerant charge
  14. Bad contact between refrigerant loop and inverter heat sink
  15. Lack of refrigerant
  16. Faulty suction thermistor
  17. Blockages in refrigerant circuit
  18. Worn or damaged compressor dampers causing vibration/noise
  19. Compressor guard timer active
  20. Normal inverter control behavior when target temperature achieved
  21. Water pump software control behaviour based on setting [F-0D]
  22. Special software control activated - water loop temperature is too low causing ONLY the backup heater to operate
  23. Faulty compressor winding
  24. High pressure switch confirmed faulty during checking procedure
  25. Flammable refrigerant remaining dissolved in compressor lubricant
  26. Wrong assembly during repair
  27. Excessive heat applied during brazing near compressor pipes

Where to start

  1. Perform a check of the discharge pipe thermistor
  2. Check that all stop valves of the refrigerant circuit are open
  3. Check if the refrigerant circuit is clogged

The full answer, free

  • 48 more checks in order
  • The readings and component tests from the manual
  • How to put it right, step by step
  • The manual page for this fault (page 40), right under the answer

Safety: Isolate the outdoor unit and any backup heater, and give the inverter capacitors time to discharge before you open the electrics. Anything on the refrigerant circuit needs F-gas certification.

From the Daikin manual for the Altherma. Check the model on the data plate before you order parts.

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