Mitsubishi Electric City Multi CMB-P1016NU-G, Service Handbook

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[
IX
Troubleshooting ]
2135 Water heat ex-
changer freez-
ing 1. If the following condi-
tions are met (1st
time) during the oper-
ation, the heat source
unit comes to a stop,
goes into 3-min. re-
start prevention mode,
and restarts after
three minutes.
[Conditions]
Detection of the tem-
perature of 3°C[37°F]
or below by the water
heat exchanger outlet
pipe sensor (TH9), or
the detection of the
compressor frequency
of lower than the mini-
mum frequency 20Hz
+10 and the fifteen
continuous minutes of
evaporating tempera-
ture Te detection of
higher than -10°C [14
°F] .
2. If the above conditions
are met (2nd time)
within sixty minutes of
the stoppage of heat
source unit, the unit
comes to an abnormal
stop and displays the
code "2135."
3. If the above conditions
are met (2nd time) af-
ter sixty minutes have
passed since the stop-
page of heat source
unit, it is considered
as the first detection,
and the same se-
quence of operation
as the one in item 1
above is followed.
(1) Heat source water pump
failure
(2) Problems with the heating
device
(3) Dirty or clogged water heat
exchanger
(4) Broken lead wire for water
heat exchanger freeze
prevention Thermo
(5) Disconnected connector
for water heat exchanger
freeze prevention Thermo
(6) Failure of the water heat
exchanger freeze preven-
tion Thermo input circuit
on the relay board
(7) Failure of the water heat
exchanger freeze preven-
tion Thermo input circuit
on the control board
Error Code
Error definition and error
detection method
Cause Check method and remedy