Mitsubishi Electric EHPT20X-VM2HA, Руководство по обслуживанию

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Error code Title and display conditions Possible Cause Diagnosis and action
L3 Circulation water temperature overheat
protection
<DHW/Heating/LP/FS/OS>
Error code displayed when THW1 detects
a temp. ≥ 80ºC for 10 consecutive seconds
or THW2 detects a temp ≥ 80ºC for 10
consecutive seconds.
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 rec
-
ommended range.
3 Valve operation fault 3
Check valves on primary water circuit are
installed 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
Booster heater relay (BHC1, BHC2, BHCP)
operating fault
6
Electrically test the relays (BHC1, BHC2,
BHCP) to determine fault.
See 10-6. for how to check.
7
Power supply voltage increase
7
Check the supply voltage.
8 THW1 or THW3 or THW5B has become
detached from its holder. 8 Visually inspect location and reattach as
necessary.
9
THW1 or THW fault
9
Check resistance of thermistor against table
in section 10-6.
Compare FTC3 detected temperature to
hand held detector.
0 FTC3 board failure 0 Replace board.
L4 Tank water temperature overheat protection
<DHW/Heating/LP/FS/OS>
Error code display when THW5B detects a
temp. ≥ 75ºC for 10 consecutive seconds.
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
Immersion heater relay (IHC) operating fault
2
Check immersion heater relay (IHC)
3 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.
L5 Indoor unit temperature thermistor
(TH1, TH2, THW1, THW2, THW5B) failure
<DHW/Heating/LP/FS/OS>
Error code displayed when thermistor is at
open or short (see table).
Exceptions
Error code will not be displayed for TH2;
During defrost and for 10 mins after defrost
operation.
1
Connector/terminal wire has become
detached or loose wiring.
1 Visually check the terminals and connections
and reattachas appropriate.
2 Thermistor fault 2
Check resistance of thermistor against table
in section 10-6.
Compare FTC3 detected temperature to
hand held detector.
3 FTC3 board failure 3 Replace board.
4
The thermistor on the wireless remote con
-
troller or the main remote controller may be
defective. (when Room temp. is chosen for
the Heating operation and when Main Con
-
troller 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
5
Incorrect setting of the Dip switch(es)
5
Check the Dip switch setting(s).
Thermistor
Open detection Short detection
Symbol Name
TH1 Room temperature thermisitor
-39ºC or below 88.5ºC or above
TH Liquid temperature thermisitor
-39ºC or below 88.5ºC or above
THW1
Flow water temperature thermisitor -39ºC or below 88.5ºC or above
THW
Return water temperture thermisitor -39ºC or below 88.5ºC or above
THW5B
Tank water temperture thermisitor -39ºC or below 88.5ºC or above