Mitsubishi Electric City Multi PQHY-P72 Service Handbook page 192

Error definition and error
Error Code
detection method
1102 Abnormal dis- 1. If the discharge tem-
charge air tem- perature of 120°C
perature [248°F] or more is de-
tected during the
above operation (the
first detection), the
heat source unit stops
once, turns to anti-re-
start mode for 3 min-
utes, and restarts after
3 minutes automati-
cally.
2. If the discharge tem-
perature of 120°C
[248°F] or more is de-
tected again (the sec-
ond detection) within
30 minutes after the
second stop of the
heat source unit de-
scribed above, the
mode will be changed
to 3-minute restart
mode, then the heat
source unit will restart
in 3 minutes.
3. If the discharge tem-
perature of 120°C
[248°F] or more is de-
tected (the third detec-
tion) within 30 minutes
after the stop of the
heat source unit de-
scribed above (re-
gardless of the first or
the second stop), the
heat source unit will
make an error stop,
and the error code
"1102" will be dis-
played.
4. If the discharge tem-
perature of 120°C
[248°F] or more is de-
tected more than 30
minutes after the pre-
vious stop of the heat
source unit, the detec-
tion is regarded as the
first detection, and the
operation described in
step 1 above will start.
5. For 30 minutes after
the stop (the first stop
or the second stop) of
the heat source unit,
preliminary errors will
be displayed on the
LED display.
Cause
(1) Gas leak, gas shortage
(2) Overload operation
(3) LEV failure on the indoor
unit
(4) Heat source unit LEV1
malfunction
(5) Solenoid valve malfunc-
tion (SV4a-4d)
-> Heating
(6) Closed ball valve
(7) Insufficient heat source
water supply, heat source
water supply cutoff, dirty or
clogged water heat ex-
changer
-> Heating
Items (3)-(7) are caused
by a rise in the discharge
temperature due to a drop
in pressure.
(8) Gas leak between low and
high pressures
(4-way valve failure, com-
pressor failure, solenoid
valve (SV1) failure)
(9) Thermistor failure
(TH1)
(10) Input circuit failure on the
controller board thermistor
- 183 -
[ IX Troubleshooting ]
Check method and remedy
Refer to the page on refrigerant
amount evaluation.
Check operating conditions and op-
eration status of indoor/heat source
units.
Perform a cooling or heating opera-
tion and check the operation.
Cooling : LEV on the indoor unit,
LEV1
Heating : LEV on the indoor unit,
SV4a-4d
Refer to the section "Troubleshoot-
ing the LEV and solenoid valve."
Confirm that the ball valve is fully
open.
Check for dirty or clogged water heat
exchanger
Check the heat source water pump
Perform a cooling or heating opera-
tion and check the operation.
Check the thermistor resistor.
Check the inlet air temperature on
the LED monitor.