Daikin Altherma fault E5-00

What it means

Compressor overload is detected.

Likely causes

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

Where to start

1. Check that all stop valves of the refrigerant circuit are open
2. Perform a check of the discharge pipe thermistor
3. Perform a check of the outdoor unit fan motor