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

Page: 199 / 349

- 190 -
[
IX
Troubleshooting ]
2502 Drain pump
failure
(The error
code blinks on
the indoor unit
in trouble.) When the drain sensor
detects water or its tip be-
comes immersed in wa-
ter during drain pump
operation. (1) Drain pump malfunction
(2) Clogged drain pump intake
(3) Clogged drain pipe
(4) Return water from drain
pipe (Improper installation)
1) Check for drain pump malfunc-
tion
Œ
Check whether there is water
in the drain pan.
When the water level is ap-
proximately 10mm [13/32"]
from the bottom of the drain
pan, the drain pump may be
normal.
ΠCheck 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
clogging 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 water
returns, the gradient of drain
pipe may be the reason.Check
whether the drain pipe is in-
stalled properly as the instruc-
tions in the installation manual
say.Furthermore, check wheth-
er the gradient of the unit instal-
lation is horizontal.An error may
occur due to return water de-
pending on the gradient.
Target gradient approximately
0.5°)
After checking the above, when all
normal, misdetection of the drain
sensor is possible.
ΠCheck the drain sensor.
Check the resistance value
<Error reset method>
Error reset the applicable indoor
unit, using the remote controller.
Drain pump fail-
ure
(The error code
blinks on all the
indoor units in the
system with one
indoor unit.)
When the drain sensor
detects water or its tip be-
comes immersed in wa-
ter during drain pump
operation on stopping in-
door units. (1) Drain pump malfunction
(2) Clogged drain pump intake
(3) Clogged drain pipe
(4) Return water from drain
pipe (Improper installation)
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.
Error Code
Error definition and error
detection method
Cause Check method and remedy