Mitsubishi Electric PUHY-M200YNW-A1 Service Handbook page 197

[7-6 Error Code Definitions and Solutions: Codes [4000 - 4999] ]
7-6-12 Error Code [4131]
1. Error code definition
Slightly open indoor unit valve during power cut
2. Error definition and error detection method
On the indoor units to which no power is supplied, when a temperature difference of 10°C or greater is detected between the
return air temperature (TH1) and the inlet water temperature (TH2) continuously for 5 minutes during cooling operation, the
error code [4131] will be displayed, and the system will come to an abnormal stop.
3. Cause, check method and remedy
(1) Slightly open indoor unit flow control valve due to pow-
er cut
(2) Thermistor failure
(3) Failure in the indoor unit flow control valve
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- chapter 7
Cause Check method and remedy
Turn on the power supply.
Check the thermistor value on the LED.
Check the operation of the flow rate control valve.
See [8-8-4 General Overview on FCV Operation (In-
door unit)] for the valve operation.
BS_07_E