Mitsubishi Electric PUHY-P120YHMU-A, Service Manual

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[
IX
Troubleshooting ]
- 158 - HWE0804A GB
1. Error Code
Drain sensor submergence (Models with a drain sensor)
2. Error definition and error detection method
1) If an immersion of the drain sensor in the water is detected while the unit is in any mode other than the Cool/Dry mode and
when the drain pump goes from OFF to ON, this condition is considered preliminary water leakage. While this error is being
detected, humidifier output cannot be turned on.(Applicable to the units manufactured in or after October 2006)
2) If the immersion of the sensor in the water is detected four consecutive times at an hour interval, this is considered water leak-
age, and "2500" appears on the monitor.
3) Detection of water leakage is also performed while the unit is stopped.
4) Preliminary water leakage is cancelled when the following conditions are met:
ΠOne hour after the preliminary water leakage was detected, it is not detected that the drain pump goes from OFF to ON.
ΠThe operation mode is changed to Cool/Dry.
Œ The liquid pipe temperature minus the inlet temperature is -10°C [-18°F] or less.
3. Cause, check method and remedy
2500
Cause Check method and remedy
(1) Drain water drainage problem
ΠClogged drain pump
ΠClogged drain piping
ΠBackflow of drain water from other units
Check for proper drainage.
(2) Adhesion of water drops to the drain sensor
ΠTrickling of water along the lead wire
ΠRippling of drain water caused by filter clogging
1) Check for proper lead wire installation.
2) Check for clogged filter.
(3) Failure of the relay circuit for the solenoid valve Replace the relay.
(4) Indoor unit control board failure
ΠDrain sensor circuit failure
If the above item checks out OK, replace the indoor unit
control board.