Rheem RHMV2421MNACJA Service Manual page 75

Troubleshooting 18
Discharge temperature sensor error
Detective actuators:
Discharge temperature thermistor
Detective details:
Discharge temperature thermistor short detected
Discharge thermistor open detected
Forecast of cause :
1. Connector connection failure, open
2. Thermistor failure
3. Main PCB failure
Check Point 1 : Check connector connection and cable open
Connector connection state check
Cable open check
OK
Check Point 2 : Check thermistor
Thermistor characteristics check (Disconnect thermistor from PCB and check.)
(PARTS INFORMATION 7)
OK
Check Point 3 : Check voltage of main PCB (DC 5.0V)
Main PCB (CN63:1-3) voltage value = 5V (RP1724/1730HJVXA)
Main PCB (CN63:1-2) voltage value = 5V (RP1736/1748HJVXA)
Disconnect thermistor from main PCB, and check voltage.
RP1724HJVXA
RP1730HJVXA
If the voltage does not appear, replace main PCB,
and execute the check operation again.
RP1736HJVXA
RP1748HJVXA
1 2 3
1 2 3
CN63
Indicate or Display:
Indoor unit
Operation lamp: 7 times Flash,
Timer lamp
Wired remote control
Error code : [E : 71]
Outdoor unit (RP1736/1748HJVXA)
Mode Error
2
: Light OFF
1 2 3 4
1 2 3 4
CN63
03-25
: 1 time Flash
A B C D E
7
1
: Light ON n : n times blinking
DC
F