Indoor Unit Related Examples
Si30-408
122
Cases for Examination
2.2
Water Leakage from the Ceiling Duct
Applicable
Models
FXYM Optional humidifier (Japanese Domestic case)
Condition
Indoor unit with ceiling duct +Natural evaporation type humi High-lift drain-up kit
Water leakage occurs when the power of (FXYMJ140KC) and (KNMJ30L140) indoor units is
shut off.
Cause
Drain from the equipment and the one from the humidifier are designed to flow together to the
drain-up kit and the drain-up kit is designed to operate when voltage is applied. However, the
drain flows back and is not drained completely during operation due to negative pressure on the
equipment side and the drain rushes to the drain-up kit when the operation is stopped. Since the
drain-up kit does not operate when the power is shut off, water leakage occurs.
Measure
Install a trap to the drain on the equipment side.
Point of
Diagnosis
Humidifier
Fan
Heat exchanger
Air
Air
Outlet
Trap
Drain-up kit
Drain
Negative pressure
Positive
pressure
