Error Code [2503] - Mitsubishi Electric PURY-M200YNW-A1 Service Handbook

[7-4 Error Code Definitions and Solutions: Codes [2000 - 2999] ]
7-4-6

Error Code [2503]

1. Error code definition
Drain sensor (Thd) fault
2. Error definition and error detection method
If the open or short circuit of the thermistor has been detected for 30 seconds, this condition is considered to be a preliminary
error, and the unit goes into the 3-minute restart delay mode.
If another episode of the above condition is detected during the preliminary error, this is considered a drain sensor error.(If
the short or open circuit of the thermistor is no longer detected, normal operation will be restored in 3 minutes.)
This error is detected when one of the following conditions are met.
During Cool/Dry operation
Liquid pipe temperature minus inlet temperature is equal to or smaller than -10°C [-18°F] (except during the defrost cycle)
When the liquid temperature thermistor or suction temperature thermistor or short or open circuited.
Drain pump is in operation.
One hour has elapsed since the drain sensor went off.
Short: 90°C [194 °F] or above
Open: - 20°C [-4 °F] or below
3. Cause, check method and remedy
(1) Faulty connector (CN31) insertion.
(2) Broken or semi-broken thermistor wire
(3) Thermistor failure
(4) Indoor unit control board (error detection circuit)
failure
20
- chapter 7
Cause Check method and remedy
1) Check for connector connection failure.
Reinsert the connector, restart the operation, and check for
proper operation.
2) Check for a broken thermistor wire.
3) Check the resistance of the thermistor.
0°C[32 °F]:6.0 kΩ
10°C[50 °F]:3.9 kΩ
20°C[68°F]:2.6 kΩ
30°C[86°F]:1.8 kΩ
40°C[104 °F]:1.3 kΩ
4) Replace the indoor unit control board if the problem recurs
when the unit is operated with the No.-1 and No.-2 pins on
the drain sensor connector (CN31) being short-circuited.
If the above item checks out OK, there are no problems with
the drain sensor.
Turn off the power and turn it back on.
BS_07_M