GCH15010
38
Error code
Title and display conditions
Possible Cause
Diagnosis and action
P1/L5
Indoor unit temperature thermistor failure
* The thermistors subject to failure can be checked
in “Request code: 567” in “Running information
<DHW/Heating/LP/FS/OS>
Error code displayed when thermistor is at open or
short (see table).
1.
Connector/terminal wire has become
detached or loose wiring.
1.
Visually check the terminals and connec-
tions and reattaches appropriate.
2.
Thermistor fault
2.
Check resistance of thermistor against
table in section 10-6.
Compare FTC detected temperature to
hand held detector.
3.
FTC board failure
3.
Replace board.
4.
The thermistor on the wireless remote
controller or the main remote control-
ler may be defective. (when Room
temp. is chosen for the Heating opera
tion and when Main remote controller
or Room RC 1-8 is chosen for the
Room Sensor setting in the Initial
setting)
4.
Replace wireless remote controller or main
remote controller.
L6
Circulation water freeze protection
<DHW/Heating/FS/OS>
Error code displayed when THW1 detects a
WHPS&IRUFRQVHFXWLYHVHFRQGVRU
7+:GHWHFWVDWHPS&IRUFRQVHFXWLYH
seconds.
Exception
Error code will not be displayed if;
FS function is disabled,
For 10 minutes after water circulation pump1 is
switched on.
1.
2. Valve operation fault
3. 2-way valve (local supply) actuator
fault
4. 3-way valve actuator fault
5. THW1 or THW2 has become detached
from its holder.
5. Visually inspect location and reattach as
necessary.
6. THW1 or THW2 fault
6. Check resistance of thermistor against table
in section 10-6.
Compare FTC detected temperature to
hand held detector.
7. FTC board failure
7. Replace board.
Reduced flow in primary water circuit
Due to 1 or more of the following;
Faulty pump, insufficient air purge,
blocked strainer, leak in water circuit
Error code
Thermistor
Open detection
Short detection
Symbol
Name
P1
TH1A/TH1B
Room temperature thermisitor
&RUEHORZ
&RUDERYH
L5
THW1
Flow water temperature thermisitor
&RUEHORZ
&RUDERYH
THW2
Return water temperture thermisitor
&RUEHORZ
&RUDERYH
THW3
Flow water temp. thermisitor (to tank)
&RUEHORZ
&RUDERYH
THW4
&RUEHORZ
&RUDERYH
THW5A
Stored water temp. thermistor (upper)
&RUEHORZ
&RUDERYH
THW5B
&RUEHORZ
&RUDERYH
DHW supply temp. thermistor
Stored water temp. thermistor (lower)
1.
Check circulation pump (See 10-6. for how
to check).
Open air vent to remove trapped air.
Check the strainer for blockages.
Check the primary water circuit for leaks.
Check that the flow amount is within the
recommended range during heating
operation.
Refer to Procedure 5 in “11. DISASSEMBLY
PROCEDURE.”
2.
Check valves on primary water circuit are
installed level.
3.
Electrically test to determine fault
4.
1) Electrically test to determine fault.
2) Operate 3-way valve manually using
the main remote controller. (Refer to
<Manual operation> in 9-4).
3) Replace 3-way valve coil.
4) Replace 3-way valve. (Refer to Procedure
6 in “11. DISASSEMBLY PROCEDURE.”
L8
Heating operation error
* “3” is displayed in “Request code: 567” in “Run-
ning information”.
<Heating/FS>
If a), b) and c) occur, L8 is displayed;
a) No change on THW1
(under 1°C for 20 minutes from unit starts
operation)
b) No change on THW1
(under 1°C for 10 minutes from booster heater
starts operation)
c) THW1 - THW2 < -5°C
(for 10 minutes continuously)
1.
THW1 has become detached from its
holder.
1.
Visually inspect location and reattach as
necessary.
2.
Booster heater fault
2.
Electrically test to determine fault.
See 10-6. for how to check.
3.
THW1 or THW2 fault
3.
Check resistance of thermistor against
table in section 10-6.
Compare FTC detected temperature to
hand held detector.
4.
FTC board failure
4.
Replace board.
