Service manual

23
Error Code
Abnormal points and detection method Judgment and action
Case
Freezing/overheating protection is oper-
ating
Overheating protection <Heating mode>
Abnormal if condensing temperature of
pressure sensor (63HS) detects
Tcond. °C or more and compressor
operation frequency is less than or equal
to 25 Hz. Detection is inoperative during
defrosting.
1 Overcharge of refrigerant
2
Defective refrigerant circuit (clogs)
3 Malfunction of linear expansion valve
4 Reduced water flow
· Clogged filter
· Leakage of water
5 High temperature
· Over-load
· Inlet water is too warm.
6 Defective water pump
12 Check operating condition of refrigerant
circuit.
3 Check linear expansion valve.
45 Check water piping.
6 Check water pump.
Ambient temperatur
e
stage-g
stage-f
stage-e
stage-d
stage-c
stage-b
stage-a
Tcond
stage-a stage-b stage-c stage-d stage-e stage-f stage-g
-18 -17 -15 -14 -12 -11 -9 -8 -6 -5 -3 -2
Tcond
SW40/50 63 61 60 58 56 53 50
P6
1
–
3
Check resistance value of thermistor.
0: 15.0k"
10
:
9.6k
"
20
:
6.3k
"
30: 4.3k"
40: 3.0k"
If you put force on (draw or bend) the lead wire
with measuring resistance value of thermis-
tor, breaking of wire or contact failure can be
detected.
2
Check contact failure of TB61 No.5-6 on
PCB of Interface unit/Flow temp. controller.
Refer to 7. WIRING DIAGRAM.
Turn the power on again and check restart
after inserting connector again.
4
Check actual tank temperature display on
remote controller.
Replace PCB of Interface unit/Flow temp.
controller if there is abnormal difference with
actual tank temperature.
Turn the power off, and on again to operate
after check.
1
Defective thermistor character-
istics
2
Contact failure of TB61 No. 5-6
on PCB of interface unit/Flow
temp. controller
3
Breaking of wire or contact
failure of thermistor wiring
4
Defective PCB of interface
unit/Flow temp. controller
Actual tank temperature thermistor
(TH5)
1
The unit is 3-minute resume preven-
tion mode if short/open of thermistor is
detected. Abnormal if the unit does not
reset normally after 3 minutes. (The unit
returns to normal operation, if it has been
reset normally)
2
Constantly detected during cooling,
heating, heating ECO, anti freeze and
hot water operation.
P9
OCH525