61
OCH439M
Check Code Abnormal point and detection method
Cause
Judgment and action
P6
Freezing/overheating protection is working
(1) Freezing protection
<Cooling mode>
Abnormal if plate heat exchanger pipe
temperature (TH6) stays at −5
:
or
lower for 10 seconds or abnormal if
plate heat exchanger pipe thermistor
(TH6) stays at −2
:
or lower and com-
pressor operation frequency is mini-
mum for 5 minutes after compressor
starts operating for 6 minutes.
<Heating mode>
Abnormal if inlet water temperature
thermistor (TH32) is 15
:
or lower,
and the following condition (1 or 2) are
detected.
1. 1 minute has passed since defrost-
ing operation started and plate heat
exchanger pipe temperature thermistor
(TH6) stays at −6
:
or lower for con-
tinuously 30 seconds.
2. During defrosting operation and plate
heat exchanger pipe temperature ther-
mistor (TH6) stays at −16
:
or lower
for continuously 10 seconds.
(1) Freezing protection
<Cooling mode>
1
Reduced water flow
· Clogged filter
· Leakage of water
2
Low temperature
· Low-load
· Inlet water is too cold.
3
Defective water pump
4
Defective outdoor fan control
5
Overcharge of refrigerant
6
Defective refrigerant circuit (clogs)
7
Malfunction of linear expansion valve
<Heating mode>
1
Reduced water flow
· Clogged filter
· Leakage of water
2
Low temperature
· Low-load
· Inlet water is cold.
3
Defective water pump
4
Leakage or shortage of refrigerant
5
Malfunction of linear expan-
sion valve
(1) Freezing protection
<Cooling mode>
12
Check water piping.
3
Check water pump.
4
Check outdoor fan motor.
5
–
7
Check operating condition of refrigerant
circuit.
7
Check linear expansion valve.
<Heating mode>
12
Check water piping.
3
Check water pump.
4
Correct to proper amount of refrigerant.
5
Check linear expansion valve. Refer to "9-5.
HOW TO CHECK THE COMPONENTS".
P8
Pipe temperature
Abnormal if the following conditions are
detected for continuously 3 minutes after
compressor starts operating for 10 minutes.
1. Cooling mode
T
63HS−
TH7
[
2
:
and
TH3−TH7
[
4
:
or T
63HS
−TH3 < 0
:
and
TH32−TH6
[
0
:
and
Compressor operation frequency is
61Hz or more.
2. Heating mode
T
63HS
−TH32
[
2
:
and
TH6−TH32
[
1
:
and
TH7−TH3
[
1
:
and
Compressor operation frequency is
61Hz or more.
T
63HS
: Condensing temperature of pres-
sure sensor (63HS)
Thermistor
TH3: Liquid temperature
TH32: Inlet water temperature
TH6: Plate HEX Liquid temperature
TH7: Ambient temperature
1
Leakage or shortage of
refrigerant
2
Malfunction of linear expansion
valve
3
Refrigerant circuit is clogged
with foreign objects.
Note: Clogging occurs in the
parts which become below
freezing point when water
enters in refrigerant circuit.
4
Disconnection of thermistor
holder
1
Check intake superheat.
Check leakage of refrigerant.
2
Check linear expansion valve.
3
After recovering refrigerant, remove water
from entire refrigerant circuit under vacuum
more than 1 hour.
4
Check temperature display on outdoor
controller circuit board.
Temperature display is indicated by setting
SW2 of outdoor controller circuit board.
Check the holder of thermistor.
UE
Abnormal pressure of pressure sensor
(63HS)
Abnormal if pressure sensor (63HS)
detects 0.1 MPa or less.
Detection is inoperative for 3 minutes after
compressor starting and 3 minutes after
and during defrosting.
1
Disconnection or contact fail-
ure of connector (63HS) on
the outdoor controller circuit
board
2
Defective pressure sensor
3
Defective outdoor controller
circuit board
1
Check connection of connector (63HS) on
the outdoor controller circuit board.
Check breaking of the lead wire for thermis-
tor (63HS).
2
Check pressure by microprocessor. (Pressure
sensor/ 63HS) (SW2: Refer to "9-7.
OUTDOOR UNIT OPERATION MONITOR
FUNCTION".)
3
Replace outdoor controller board.
PE
Inlet water temperature
Abnormal if the following conditions are
detected for continuously 10 seconds.
1. Cooling mode
During compressor operation
TH32 < 3
:
2. Heating mode (exclude defrosting)
During compressor operation
TH32 < −10
:
3. Defrosting mode
During compressor operation
TH32 < 0
:
Thermistor
TH32: Inlet water temperature
1
Reduced water flow
· Clogged filter
· Leak of water
2
Low temperature
· Low-load
· Low temperature inlet water
3
Defective water pump
4
Leakage or shortage of refrig-
erant
12
Check water piping.
3
Check water pump.
4
Check intake superheat.
Check leakage of refrigerant.