Fujitsu ASUH18LMAS User Manual

2-20. E: 73.X. Heat exchanger (Middle/Outlet) temperature
thermistor error (Outdoor unit)
Indicator
Indoor unit
Operation indicator 7 time flash
Timer indicator 3 time flash
Economy indicator Continuous flash
Error code E: 73
outdoor unit Refer to "Error code table (Outdoor unit)" on page 03-4
Detective actuator
Heat exchanger liquid temperature
thermistor
• Heat exchanger liquid temperature thermistor short
or open detected
• Heat exchanger middle temperature thermistor
short or open detected
Heat exchanger middle
temperature thermistor
Forecast of cause
Connector failure
Thermistor failure
Main PCB failure
Check Point 1 : Check the connector connection and cable open
• Connector connection state check
• Cable open check

Check Point 2 : Check the thermistor
• For the outdoor unit heat exchanger thermistor resistance value, refer to "Ther-
mistor resistance values" on page 03-88.
• If thermistor is either open or shorted, replace it and reset the power.

Check point 3. Check voltage of main PCB
Make sure circuit diagram of outdoor unit and check terminal voltage at thermistor
(DC 5.0 V).
NOTE: For details of thermistor connector, refer to "→iring diagrams" in Chapter 2.
TECHNICAL DATA AND PARTS LIST on page 02-18.
If the voltage does not appear, replace main PCB.

End
2-20. E: 73.↓. Heat exchanger (Middle/Outlet) temperature thermistor error (Outdoor
unit)
- (03-35) - 2. Troubleshooting with error code
TROUBLESHOOTING TROUBLESHOOTING

Fujitsu ASUH18LMAS Specifications

General

Brand	Fujitsu
Model	ASUH18LMAS
Category	Air Conditioner
Language	English