GCH15010
37
10-4. Self diagnosis and action
Check if DIP SW is set correctly. (Refer to Section 6-2.)
Error code
Title and display conditions
Possible Cause
Diagnosis and action
L3
Circulation water temperature overheat
protection
<DHW/Heating/FS/OS>
Error code displayed when THW1 detects a
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7+:GHWHFWVDWHPS&IRUFRQVHFXWLYH
seconds or
7+:GHWHFWVDWHPS&IRU
FRQVHFXWLYH
seconds.
1.
1.
Check
FLUFXODWLRQ
SXPS
(See
for how
to check).
Open
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r.
Check the strainer for blockages.
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Check that the flow
DPRXQ
t is within the
recommended range
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operation.
Refer to P
URFHGXU
e 5 in “11. DISASSEMBLY
PROCEDURE.”
2.
V
DOYHRSHUDWLRQIDXOW
2.
Check
Y
al
Y
es on primary water circ
XL
t are
LQVWDOOHGOHYHO
3.
ZD\YDOYHORFDOVXSSO\DFWXDWRU
IDXOW
3.
(OHFWULFDOO\WHVWWRGHWHUPLQHIDXOW
4.
ZD\YDOYHDFWXDWRUIDXOW
4.
(OHFWULFDOO\WHVWWRGHWHUPLQHIDXOW
2) Operate 3-way
Y
al
Y
e
PDQXDOO
y
X
sing
the main remote controller. (Refer to
0DQXDORSHUDWLRQ!LQ
5HSODFHZD\YDOYHFRLO
4) Replace 3-wa
\Y
al
Y
e. (Refer to P
URFHGXU
e
6 in “11. DISASSEMBLY PROCEDURE.”
5.
Booster heater relay (CNBH) operating
IDXOW
5.
Electrically test the relays (CNBH) to
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6HHIRUKRZWRFKHFN
6.
3RZHUVXSSO\YROWDJHLQFUHDVH
6.
&KHFNWKHVXSSO\YROWDJH
7.
THW1 or THW2 has become de-
tached from its holder.
7.
Vis
XDOO
y inspect location and reattach as
necessary.
THW1 or THW2 or THW3
IDXOW
Check resistance of thermistor against ta-
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Compare FTC detected temperat
XUH
to
hand held detector.
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Replace board.
L4
Tank water temperature overheat protection
<DHW/Heating/FS/OS>
Error code display when THW5A detects a
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1.
ZD\YDOYHDFWXDWRUIDXOW
1.
(OHFWULFDOO\WHVWWRGHWHUPLQHIDXOW
2) Operate 3-way
Y
al
Y
e
PDQXDOO
y
X
sing
the main remote controller. (Refer to
0DQXDORSHUDWLRQ!LQ
5HSODFHZD\YDOYHFRLO
4) Replace 3-way
YDOYH
. (Refer to P
URFHGXU
e
6 in “11. DISASSEMBLY PROCEDURE.”
2.
7+:$IDXOW
2.
Check resistance of thermistor against ta-
EOHLQVHFWLRQ
Compare FTC detected temperat
XUH
to
hand held detector.
3.
)7&ERDUGIDLOXUH
3.
Replace board.
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'XHWRRUPRUHRIWKHIROORZLQJ
)DXOW\SXPSLQVXIILFLHQWDLUSXUJH
EORFNHGVWUDLQHUOHDNLQZDWHUFLUFXLW
DHW : Domestic hot water mode
Heating : Heating mode
FS : Freeze stat
OS : Operation stop
TH1A/B : Room temp. thermistor
THW1 : Flow water temp. thermistor
7+:5HWXUQZDWHUWHPSWKHUPLVWRU
THW3 : Flow water temp. thermistor 2 (to tank)
7+:'+:VXSSO\WHPSWKHUPLVWRU
7+:$6WRUHGZDWHUWHPSWKHUPLVWRUXSSHU
THW5B : Stored water temp. thermistor (lower)