1. Daikin Altherma™ Troubling Shooting

2. Outlet thermistor failure
Code: 81
Part: Outlet water thermistor
Location:
Activation failure:
Possible action to resolve the problem:
Check connector
Check resitance value
Replace thermistor
R3T

3. Freeze up problem Code: 89 Part: Heat exchanger freez-up
Activation failure: Outlet water temp. too low
Location:
Possible action to resolve the problem:
Check water flow in the system. Minimum water flow system 9liter / min.
R3T

4. Freeze up problem Code: Part: Refrigerant liquid sensor
Location:Liquid pipe hydrobox
Activation failure: Temperature liquid sensor too low.
Possible action to resolve the problem:
Check refrigerant charge of the installation

5. Flow failure Code: 7H Part: Flow failure Location:
Activation failure: Flow switch open during operation (no signal)
Possible action to resolve the problem:
Check water flow in the system. (Minimum water flow system
20liter / min.)
Check water pressure in the installation. (Minimum 0.3 bar)
Check shutt OFF valves
Is water system purged
Check pressure drop and speed of the waterpump
Check pump operation
R3T

6. Outlet water temperture too high
Code: 8H
Part: Outlet water thermistor
Location: Outlet back up heater
Activation failure: If outlet water > 65°C
Possible action to resolve the problem:
Check if contactor(s) back up heater is not welded
Check if thermistor is not damaged
Check if correct resistor value of thermistor
Procedure :Refer to service manual
R3T

7. Indoor PCB failure Code: A1 Part: Indoor PCB Location: Switchbox
Activation failure:
Possible action to resolve the problem:
Replace PCB

8. Insufficient cooling or heating
Code: A5
Part: Liquid sensor hydrobox
Location:
Possible action to resolve the problem:
Check water flow in the system. (Minimum water flow system
9liter / min.)
Check water pressure in the installation. (Minimum 0.3 bar)
Check shutt OFF valves
Is water system purged
Check pressure drop and speed of the waterpump
Check refrigerant charge
Check thermistor
Procedure: refer to service
manual
R3T

9. Booster heater thermal protector
Code: AA
Part: Thermal protector booster heater or back up heater *
Location:
Possible action to resolve the problem:
Check if thermal protection is not damaged.
Check contactor of the electric BUH / BSH

10. Stucked flow switch Code: CO Part: Flow switch failure
Activation failure: Flow swith remains closed when pump is not operating
Location:
Possible action to resolve the problem:
Check for dirt in flow switch
Replace part is required
R3T

11. Heat exchanger thermistor failure
Code: C4
Part: Liquid sensor
Activation failure: Sensor broken or out of range
Location:
Possible action to resolve the problem:
Check connector
Check resistance of the sensor
Procedure: refer to servicemanual for procedure
If damaged replace part
R3T

12. Outdoor PCB failure Code: E1 Part: Outdoor PCB failure
Activation failure:
Location:
Possible action to resolve the problem:
Out of control of CPU
Voltage drop
Power loss
Noise on power supply
Defect outdoor PCB

13. Overload activation of compressor
Code: E5
Part: Overload protector compressor
Activation failure: Failure If overload protector ( >130°C) is activated twice in one hour
Location: Outdoor unit
Possible action to resolve the problem:
Refrigerant shortage.
Malfunction four way valve.
Outdoor PCB failure.
Electronic expansion valve defective.

14. Compressor start up failure
Code: E6
Part: Compressor locked
Activation failure: : Failure, if error occurs 16 times, counter reset if compressor runs normal for 5 minutes
Location: Outdoor unit
Possible action to resolve the problem:
Replace outdoor PCB
Replace compressor

15. Fan motor failure Code: E7 Part: Outdoor fan motor
Activation failure: Failure, if error occurs 16 times, counter reset if compressor runs normal for 5 minutes
Location: Outdoor unit
Possible action to resolve the problem:
Fan motor breakdown
Bad contact between PCB and fan motor
Blockage of the fan blades

16. Overcurrent failure Code: E8 Part: Compressor overcurrent
Activation failure: Failure, if current (>30 Amp) occurs 16 times. Counter reset if compressor runs normal for 5 minutes
Location: Outdoor unit
Possible action to resolve the problem:
Compressor breakdown.
Short-circuit
Defective power transistor.
Defective capacitor on inverter board.
Defective outdoor PCB.

17. Cool / Heating switching failure
Code: EA
Part: four way valve
Activation failure:
Cooling: if (room temp – liquid temperature) < -10°C
Heating: if (
Location:
Possible action to resolve the problem:

18. Sanitary water too high
Code: EC
Part: Sanitary tank temperature
Activation failure: If temperature sanitary water > 89°C
Location: Sensor inside sanitary tank
Possible action to resolve the problem:
Check position of sensor in socket
Check if contactor(s) booster heater is not welded
Check if thermistor is not damaged
Check if correct resistor value of thermistor

19. Discharge temperature too high
Code: F3
Part: Discharge sensor
Activation failure: Failure if discharge temperature > 120°C for 6 times
Location: Sensor located on the discharge pipe of compressor
Possible action to resolve the problem:
Refrigerant shortage.
Malfunction four way valve.
Defective discharge sensor.
Defective EEV driver.

20. Too high condensing pressure
Code: F6
Part:Sensor outdoor heat exchanger
Activation failure: Failure if temperature heat exchanger > 60°C
Possible action to resolve the problem:
Faulty outdoor fan
Faulty EEV
Dirty heat exchanger
Faulty thermistor

21. Too high condensing pressure
Code: FA
Part:
Activation failure:
Possible action to resolve the problem:

22. Voltage and current sensor failure
Code: H0
Part: Voltage / Current sensor
Activation failure:
No measurement of current during compressor operation.
Possible action to resolve the problem:
Reactor disconnected
Compressor disconnection
Outdoor PCB failure
Compressor defective

23. Compressor start up failure
Code: H6
Part: Compressor / Outdoor PCB
Activation failure: Failure when compressor fails to start 8 times.
Possible action to resolve the problem:
Compressor cable disconnected
Compressor
Outdoor PCB
Supply voltage out of voltage specifications

24. CT failure Code: H8 Part: Current transformer on outdoor PCB
Activation failure: Failure if compressor running freq < 55Hz and CT input < then 0.1V for 4 times
Possible action to resolve the problem:
Power transistor defective
Bad or poor electrical contact
Reactor defective
Outdoor PCB

25. Outdoor ambient thermistor
Code: H9
Part: Thermistor
Location
Activation failure: Resistance value out of range
Possible action to resolve the problem:
Check connector
Check resistance value
Replace thermistor.
Outdoor PCB

26. Discharge pipe thermistor
Code: J3
Part: Discharge pipe thermistor
Location
Activation failure: Resistance value out of range
Possible action to resolve the problem:
Check connector
Check resistance value
Replace thermistor.
Outdoor PCB

27. Outdoor heat exchanger
Code: J6
Part: Thermistor
Location
Activation failure: Resistance value out of range
Possible action to resolve the problem:
Check connector
Check resistance value
Replace thermistor.
Outdoor PCB

28. Fin thermistor switchbox
Code: P4
Part: resitance located on the outdoor PCB
Location
Activation failure: Resistance value out of range
Possible action to resolve the problem:
Outdoor PCB

29. Electrical box temperature rise
Code: L3
Part: Radiation fin thermistor
Location: Outdoor PCB
Activation failure: failure if temperature > 85°C and compressor OFF
Possible action to resolve the problem:
Defective outdoor fan
Defective Fin thermistor
Defective Outdoor PCB
Heat conductive paste

30. Radiation fin temperature rise
Code: L4
Part: Radiation fin temperature rise
Location: Outdoor PCB
Activation failure: failure if temperature > 105°C and compressor ON for 4 times
Possible action to resolve the problem:
Defective outdoor fan
Defective Fin thermistor
Defective Outdoor PCB
Heat conductive paste

31. Output overcurrent detection
Code: L5
Part:
Location: Outdoor PCB
Activation failure: failure if running current is > then preset value
Possible action to resolve the problem:
Defective power transistor
Defective outdoor PCB
Defective compressor
Poor installation condition

32. Insufficient gas Code: U0 Part: Location: Outdoor
Activation failure: see next slide
Possible action to resolve the problem:
Refrigerant shortage
Poor performance of the compressor
Defective electronic expansion valve

33. Insufficient gas
When discharge pipe temperature is 45°C higher than target value and the electronic expansion value opening is 480 pulse (max.), the adjustment is
made for insufficient gas.
When an output frequency is exceeds 40 Hz and the input current is less
than specified value, the adjustment is made for insufficient gas.

34. Low or High volttage detection
Code: U2
Part: DC detection circuit
Location: Outdoor PCB
Activation failure: Low / Over voltage. Failure when low or overvoltage occurs 16 times
Possible action to resolve the problem:
Supply voltage not within the specifications
Detection circuit defect
PAM control defective

35. Signal transmission error on outdoor PCB
Code: U7
Part: CPU & PM1
Location: Outdoor PCB
Activation failure: Failure when communication error between outdoor PCB and power module
Possible action to resolve the problem:
Replace outdoor PCB

36. Thank you for your attention!
Training course S-XAM
24-25 April 2007
Wiring the 2-way valve
1 Using the appropriate cable, connect the valve control cable to
the appropriate terminals as shown on the wiring diagram.
Wiring is different for a NC (normal closed) valve
and a NO (normal open) valve. Make sure to connect
to the correct terminal numbers as detailed
on the wiring diagram and illustrations below.
Thank you for your attention!