Mitsubishi Electric CITY MULTI PUHY-P108 Service Handbook page 284

Error definition and error
Error Code
2502 Drain pump When the drain sensor
failure detects water or its tip be-
(The error comes immersed in wa-
code blinks on ter during drain pump
the indoor unit operation.
in trouble.)
Drain pump When the drain sensor
failure detects water or its tip be-
(The error comes immersed in wa-
code blinks on ter during drain pump
all the indoor operation on stopping in-
units in the door units.
system)
detection method
(1) Drain pump malfunction
(2) Clogged drain pump intake
(3) Clogged drain pipe
(4) Return water from drain
pipe (Improper installation)
(1) Drain pump malfunction
(2) Clogged drain pump intake
(3) Clogged drain pipe
(4) Return water from drain
pipe (Improper installation)
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Cause Check method and remedy
1) Check for drain pump malfunction
Check whether there is water in the
drain pan.
Check whether there is water in
the drain pan. When the water
level is approximately 10mm [13/
32"] from the bottom of the drain
pan, the drain pump may be nor-
mal.
Check whether the drain
pump operates properly.
Check whether the resis-
tance of the drain pump is
normal or the drain pump
operates normally when the
power supply is applied.
2) Check for clogged drain pump intake
Check whether there is no
dust around the drain pump
intake.
3) Check for clogged drain pipe
Check whether there is no clog-
ging outside of the pipe body.
4) Check for return water.
Pour approximately 1-liter
water in the drain pump, and
start the drain pump. When
the water level in the drain
pan becomes steadily lower,
stop the pump, and check the
amount of the return water to
the drain pan.
*When a large amount of wa-
ter returns, the gradient of
drain pipe may be the rea-
son. Check whether the
drain pipe is installed prop-
erly as the instructions in
the installation manual say.
Furthermore, check wheth-
er the gradient of the unit in-
stallation is horizontal. An
error may occur due to re-
turn water depending on the
gradient.
(Target gradient approxi-
mately 0.5 °)
After checking the above, when all
normal, misdetection of the drain
sensor is possible.
Check the drain sensor.
Check the resistance value
<Error reset method>
Reset (error reset) the indoor unit in
trouble with the remote controller.
Same as above
<Error reset method>
Reset the power of the indoor unit in trou-
ble.However, the reset with the remote con-
troller (error reset) must be made 10
minutes later after the power has been re-
set. All the indoor units must be reset with
the remote controller.
[ IX Troubleshooting ]