Mitsubishi Electric PQHY-P120THMU-A, Service Handbook

Page: 248 / 414

[
IX
Troubleshooting ]
- 239 - HWE09080 GB
1. Error Code
Drain sensor submergence (Models with a float switch)
2. Error definition and error detection method
1) If an immersion of the float switch 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.
2) If the drain pump turns on within one hour after preliminary water leakage is detected and the above-mentioned condition is
detected two consecutive times, water leakage error water leakage is detected, 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:
One hour after the preliminary water leakage was detected, it is not detected that the drain pump goes from OFF to ON.
The operation mode is changed to Cool/Dry.
Liquid pipe temperature - inlet temperature - 10°C[-18°F]
3. Cause, check method and remedy
<Reference>
2500
Cause Check method and remedy
(1) Drain water drainage problem
Œ
Clogged drain pump
Œ
Clogged drain piping
Œ
Backflow of drain water from other units
Check for proper drainage.
(2) Stuck float switch
Check for slime in the moving parts of the float
switch. Check for normal operation of the float switch.
(3) Float switch failure Check the resistance with the float switch turned on and
turned off.
6 minutes 6 minutes
15
seconds
15
seconds
15
seconds
15
seconds
15
seconds
ON
OFF
ON
OFF
Drain pump operation triggered by a submergence of the liquid level sensor
(except during the Cooing/Dry mode)
Drain pump
output
Float switch
input
Submergence of
the sensor
Submergence of
the sensor
Preliminary water leakage
Submergence of
the sensor
Water leakage
Sensor in the air Sensor in the air
Within 1-hour period Within 1-hour period