Mitsubishi Electric CITY MULTI PUHY-80TMU-A Service Handbook page 69

Checking code Meaning, detecting method
2500 Leakage When drain sensor detects
(water) trouble flooding during drain pump
OFF.
2502 Drain pump The drain sensor's water drain*
trouble and after the drain pump is turn
on for more than three minuites.
D rain sensor's water drain
condition when indirect heater
of drain after 40 second's.
• Rise in temperature of drain
sensor is 20 deg or less or
• The temperature of the
drain sensor is 63°C or less.
2503 Drain sensor Short/open is detected during
trouble drain pump operations. (Not de-
tected when drain pump is not
operating.)
Short : 90°C or more detected
Open : –40°C or less de-
tected
Water leak
2600
trouble
Water
2601
suspension
trouble
Operation of When Float switch operates
float switch (point of contact : OFF), error
stop is observed with code No.
"2503" displayed.
1) Water leak due to humidifier or the
like in trouble.
1) Drain sensor sinks in water be-
cause drain water level rises due to
drain water lifting-up mechanism
trouble.
2) Broken wire of indirect heater of
drain sensor
3) Detecting circuit (circuit board)
trouble
Indoor LEV operation is faulty.
4) The trable of indoor LEV
1) Thermistor trouble
2) Poor contact of connector
(insufficient insertion)
3) Full-broken of half-broken ther-
mistor wire
4) Indoor unit circuit board (detecting
circuit) trouble
—
Water leak from piping of humidifier
— 1) Water is not supplied to water tank
for humidifying.
2) The solenoid valve for humidifying
is set to OFF.
3) Disconnection of float switch.
4) Faulty operation of float switch.
5) Freezing of water tank.
1) Drain up input trouble
2) Poor contact of float switch circuit
3) Float switch trouble
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Cause Checking method & Countermeasure
Check water leaking of humidifier
and clogging of drain pan.
Check operations of drain pump.
Measure resistance of indirect
heater of drain sensor.
(Normal: Approx. 82Ω between 1–3
of CN50)
Indoor board trouble if no other
problems is detected.
Operate in fan mode checking to
make sure that the temperature of
TH2 and TH3 rise to the around the
same level.
Check resistance of thermistor
0°C : 15kΩ
20°C : 6.4kΩ
40°C : 3.1kΩ
Check contact of connector
Indoor port trouble if no other prob-
lem is detected.
Confirm water leaking section.
Confirm supply water volume.
Solenoid valve and connection
Confirm connector section.
Confirm connecting section.
Faulty float switch.
Turn power source OFF once, and
turn ON after thawaing.
Check drain pump operations
Check connect contact.
Check float switch operations.
10°C : 9.7kΩ
30°C : 4.3kΩ