Mitsubishi Electric EHPT20X-VM2HA, Руководство по обслуживанию

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Error code Title and display conditions Possible Cause Diagnosis and action
L6 Circulation water freeze protection
<DHW/Heating/LP/FS/OS>
Error code displayed when THW1 detects
a temp. ≤ 1ºC for 10 consecutive seconds
or THW2 detects a temp. ≤ 3ºC for 10 con
-
secutive seconds.
Exception
Error code will not be displayed if;
FS function is disabled,
For 10 mins after water circulation pump1 is
switched on.
1
Insufficient system head
1
Refer to table in section 10-6. to determine if
system pump meets requirements.
If more head required either add an pump of
the same size or replace existing pump with
capacity model.
See 11. DISASSEMBLY PROCEDURE for
how to replace pump.
2
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.
2
Check circulation pump (See 10-6. for how
to check).
Open purge valve 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.
3 Valve operation fault 3
Check valves on primary water circuit are in
-
stalled level.
4
2-way valve (field supply) actuator fault
4 Electrically test to determine fault.
5
3-way valve actuator fault
5
1) Electrically test to determine fault.
2) Operate 3-way valve manually using the
main remote controller. (Refer to <Manual
operation> in 9.2).
3) Replace 3-way valve coil.
4) Replace 3-way valve. (Refer to Procedure
6 in “11. DISASSEMBLY PROCEDURE.”
6
THW1 has become detached from its holder.
6
Visually inspect location and reattach as
necessary.
7 THW1 or THW fault 7
Check resistance of thermistor against table
in section 10-6.
Compare FTC3 detected temperature to
hand held detector.
8 FTC3 board failure 8 Replace board.
L7 3-way valve failure (Valve direction
defaults to DHW circuit)
<Heating/FS>
If a) and b) occur, L7 is displayed;
a) No change on THW1 (under 1 °C for 20
minutes from unit starts operation)
b) THW5B goes up in Heating (or FS)
mode. (over 1 °C for 20 minutes)
Exception
If simultaneous Heating and DHW operation
is selected error code will not be displayed.
1
3-way valve actuator fault
1
1) Electrically test to determine fault.
2) Operate 3-way valve manually using the
main remote controller. (Refer to <Manual
operation> in 9.2).
3) Replace 3-way valve coil.
4) Replace 3-way valve. (Refer to Procedure
6 in “11. DISASSEMBLY PROCEDURE.”
2
THW1 or THW5B fault
2
Check resistance of thermistor against table
in section 10-6.
Compare FTC3 detected temperature to
hand held detector.
3 FTC3 board failure
The thermistor on the wireless remote con
-
troller or the main remote controller may be
defective.
3 Replace board.
4
Incorrect setting of the Dip switch(es)
4
Check the Dip switch setting(s)
5 THW1 or THW5B has been detached from
its holder. 5 Visually inspect location and reattach as
necessary.
L8 Heating operation error
<Heating/FS>
If a), b) and c) occur, L8 is displayed;
a) No change on THW1 and THW5B
(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 - THW < -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 THW or THW5B fault 3
Check resistance of thermistor against table
in section 10-6.
Compare FTC3 detected temperature to
hand held detector.
4 FTC3 board failure 4 Replace board.