56
Error code
Title and display conditions
Possible Cause
Diagnosis and action
P6
<Defrosting>
THW2 detects a temperature
≤
15ºC and TH2
detects a temperature
≤−
16ºC for consecutive 10
seconds.
<Defrosting>
1. Reduced water fl ow
1., 2. Check water piping.
• Clogged fi lter
• Leakage of water
2. Low temperature
• Low load
• Inlet water is cold
3. Defective water pump
3. Check water pump.
4. Leakage or shortage of refrigerant
4. Correct to proper amount of refrigerant.
5. Malfunction of linear expansion valve
5. Check linear expansion valve.
E0/E4
Main controller communication failure
(Reception error)
Error code E0 is displayed if main controller does
not receive any signal from the indoor unit for ref.
address "0" for 3 mins.
Error code E4 is displayed if indoor unit does not
receive any data from the main controller for 3
mins or indoor unit does not receive any signal
from the main controller for 2 mins.
1. Contact failure with transmission cable
1. Check connection cable for damage or
loose connections at the FTC4 and main
controller terminals.
2. Wiring procedure not observed.
(Cable length/cable diameter/number
of indoor units/number of main
controllers)
2. Check main controller and FTC4 common
wiring max cable length 500 m.
Only use 2 core cable.
Only connect 1 main controller to 1 FTC4
indoor unit board.
3. Fault on the indoor unit FTC4 board
section controlling Ref. address "0"
3.
to 5.
If the problem is not solved by the above
measures then:
Turn the power to the indoor unit OFF and
then ON.
Power to both the indoor unit and outdoor
units should be switched OFF then ON.
(This may require switching 1 or 2 breakers
depending if the unit is powered independ-
ently from the outdoor unit).
If the E4 code is still displayed the FTC4
and/or the main controller circuit board
4. Fault with the main controller circuit
board
5. Electrical noise causes interference
with transmission/reception of data for
main controller.
E3/E5
Main controller communication failure
(Transmission error)
Error code E3 is displayed if the main controller
an not fi nd an empty transmission path and thus
fails to transmit for 6 secs or the data received
bythe main controller is different to what was sent
(by the main controller) 30 consecutive times.
Error code E5 is displayed if the FTC4 can not
fi nd an empty transmission path for 3 mins and
thus cannot transmit or the data sent by the FTC4
is different to what was expected 30 consecutive
times.
1. 2 or more main controllers have been
connected to the FTC4.
1. Only connect 1 main controller to 1 FTC4
indoor unit board.
2. Fault with main controller transmission/
receiving circuit board
2. to 4.
Turn the power to the indoor unit OFF and
then ON.
Power to both the indoor unit and outdoor
units should be switched OFF then ON.
(This may require switching 1 or 2 breakers
depending if the unit is powered independ-
ently from the outdoor unit).
If the E3/E5 code is still displayed the FTC4
and/or the main controller circuit board
3. Fault with the main controller circuit
board
4. Electrical noise causes interference
with transmission/reception of data for
main controller.
E6
Indoor/outdoor communication failure
(Reception error)
Error code E6 is displayed if after the power is
switched ON to the indoor unit, the FTC4 board
does not receive any signal or the signal receive-
dis not complete for 6 mins, or after a period of
operation the FTC4 board does not receive any
signal or the signal received is not complete for 3
mins.
*
Check the LED display on the outdoor unit
circuit board.
(Connect the A-control service tool, PAC-
SK52ST to test.) Refer to the outdoor unit
service manual for explanation of EA-EC
codes.
1. Contact failure/short circuit/miswiring
1. Check the connections on the indoor and
outdoor units have not become loose and
that the connecting cable is not damaged.
2. Fault with outdoor unit transmission/
receiving circuit board
2. to 4.
Turn the power to the indoor unit OFF and
then ON.
Power to both the indoor unit and outdoor
units should be switched OFF then ON.
(This may require switching 1 or 2 breakers
depending if the unit is powered independ-
ently from the outdoor unit).
If the E6 code is still displayed the FTC4
and/or the outdoor unit circuit board should
be replaced.
3. Fault with FTC4 transmission/receiving
circuit board
4. Electrical noise causes interference
with FTC4-Outdoor unit transmission
cable.
E7
Indoor/outdoor communication failure
(Transmission error)
Error code E7 is displayed if despite the FTC4
board sending signal "0", signal "1" is received
30 consecutive times.
1. Fault with FTC4 transmission/receiving
circuit board
1.
to
3.
Turn the power to the indoor unit OFF and
then ON.
Power to both the indoor unit and outdoor
units should be switched OFF then ON.
(This may require switching 1 or 2 breakers
depending if the unit is powered independ-
ently from the outdoor unit).
If the E7 code is still displayed the FTC4
circuit board should be replaced.
2. Electrical noise causes interference
with power supply.
3. Electrical noise causes interference
with FTC4-outdoor unit transmission
cable.
OCH532A
