Fujitsu AOU18RL Service Manual (English)

Other manuals for Fujitsu AOU18RL

Operating Manual17 pages

Installation Manual14 pages

Questions and Answers:

T
Timothy DudleyAug 15, 2025
Why is my Fujitsu AOU18RL Air Conditioner cooling poorly?
- J
  Jose WilliamsAug 15, 2025
  Several factors can impact the cooling performance of your Fujitsu Air Conditioner. Check if the air filter is dirty, or if the air conditioner's intake grille or outlet port is blocked. Ensure the thermostat is set correctly and that no windows or doors are open. If it is Cooling operation, close curtains to block direct sunlight. Also, consider if there are too many heat-generating devices or people in the room. Finally, check if the unit is set to SUPER QUIET operation.
A
andreaturnerAug 18, 2025
What to do if my Fujitsu AOU18RL doesn't operate at all?
- M
  Michael Morris PhDAug 18, 2025
  If your Fujitsu Air Conditioner isn't operating, first ensure the power supply plug is properly connected to the outlet. Check for a power failure and inspect the fuse or circuit breaker. Also, verify if the timer is active.
B
Benjamin TaylorAug 21, 2025
Why is water produced from the outdoor unit of my Fujitsu AOU18RL Air Conditioner?
- J
  Jeffrey LawrenceAug 21, 2025
  Water may be produced from the outdoor unit of your Fujitsu Air Conditioner during heating operation due to automatic defrosting.
F
fpowellAug 26, 2025
Why is my Fujitsu AOU18RL Air Conditioner airflow weak or stops?
- B
  Bonnie McdowellAug 26, 2025
  There are several reasons why the airflow from your Fujitsu Air Conditioner might be weak or stop: * When heating starts, the fan speed is temporarily very low to allow internal parts to warm up. * If the room temperature rises above the thermostat setting during heating, the outdoor unit will stop, and the indoor unit will operate at a very low fan speed. To increase warmth, adjust the thermostat to a higher setting. * During heating, the unit may temporarily stop for 7 to 15 minutes for automatic defrosting. * The fan may operate at a very low speed during dry operation or when monitoring the room's temperature. * In SUPER QUIET operation, the fan runs at a very low speed. * In monitor AUTO operation, the fan runs at a very low speed.
L
Linda ParkerAug 28, 2025
How to troubleshoot Fujitsu AOU18RL operating differently from the remote control settings?
- C
  calvin41Aug 28, 2025
  If your Fujitsu Air Conditioner isn't responding to the remote control, check if the remote's batteries are dead or loaded incorrectly.
T
Teresa BlackAug 31, 2025
Why does my Fujitsu Air Conditioner smell?
- R
  Robert FisherAug 31, 2025
  A smell emitted from your Fujitsu Air Conditioner's indoor unit could be due to room odors, such as those from furniture or tobacco, that have been drawn into the unit.
N
Nicole RileySep 3, 2025
Why is mist or steam emitted from my Fujitsu AOU18RL?
- A
  Andrea NicholsonSep 3, 2025
  During cooling or dry operation, a thin mist may appear due to the sudden cooling of room air, leading to condensation. During heating, steam from the outdoor unit may occur during automatic defrosting.
R
Rachel TaylorSep 7, 2025
Why Fujitsu AOU18RL doesn’t operate immediately?
- S
  Sara RodriguezSep 7, 2025
  If your Fujitsu Air Conditioner is stopped and then immediately restarted, the compressor will not operate for about 3 minutes to prevent fuse blowouts. Also, when the power supply plug is disconnected and reconnected, the protection circuit will operate for about 3 minutes, preventing operation.
B
Brianna GuzmanSep 12, 2025
Why is my Fujitsu Air Conditioner making noise?
- L
  Laura SanchezSep 12, 2025
  During and immediately after operation, the sound of water flowing in the air conditioner's piping may be heard. Noise may be particularly noticeable for about 2 to 3 minutes after starting (coolant flowing). During heating, a sizzling sound may occur occasionally due to automatic defrosting.

Fujitsu AOU18RL Specifications

General

Brand	Fujitsu
Model	AOU18RL
Category	Air Conditioner
Language	English

Summary

Refrigerant Caution -R410A-

R410A TOOLS

Lists specialized tools and equipment required for R410A refrigerant handling.

PRECAUTION FOR INSTALLATION

Provides essential guidelines and precautions for installing equipment with R410A.

PRECAUTION FOR SERVICING

Details precautions and differences when servicing equipment with new refrigerants.

NEW REFRIGERANT R410A

Discusses the properties and phase-out schedule of HFC refrigerants like R410A.

DEFFERENCE FROM CONVENTIONAL MODEL(R22) AND PRECAUTIONS

Highlights differences in oil, compressor, and heat exchangers compared to R22 models.

Description of Each Control Operation

COOLING OPERATION

Explains the operation and capacity control for the cooling mode.

HEATING OPERATION

Details the operation and capacity control for the heating mode.

DRY OPERATION

Describes the compressor and fan control during dry operation mode.

AUTO CHANGEOVER OPERATION

Explains how the unit automatically switches between modes based on temperature.

INDOOR FAN CONTROL

Details the fan speed settings and operation for different modes.

OUTDOOR FAN CONTROL

Describes the fan speed control for the outdoor unit in various conditions.

LOUVER CONTROL

Explains the vertical and swing operation of the air direction louvers.

COMPRESSOR CONTROL

Details compressor operation frequency ranges and start-up control.

TIMER OPERATION CONTROL

Explains the functions of ON/OFF, Program, and Sleep timers.

ELECTRONIC EXPANSION VALVE CONTROL

Describes the control mechanism and pulse range of the electronic expansion valve.

TEST OPERATION CONTROL

Details how to perform a test operation and its duration.

PREVENT TO RESTART FOR 3 MINUTES (3 MINUTES ST)

Explains the compressor restart prevention feature for safety.

FOUR-WAY VALVE EXTENSION SELECT

Describes the switching timing of the four-way valve between modes.

AUTO RESTART

Explains how operation contents are memorized and restored after power interruption.

MANUAL AUTO OPERATION (Indoor unit body operation)

Describes manual operation using buttons on the indoor unit body.

FORCED COOLING OPERATION

Details the forced cooling mode activated by a specific button press.

COMPRESSOR PREHEATING

Explains the preheating function to warm the compressor before operation.

COIL DRY OR AIR CLEAN OPERATION CONTROL

Describes special functions for coil drying and air purification.

DEFROST OPERATION CONTROL

Details the conditions for starting and completing defrost operations.

OFF DEFROST OPERATION CONTROL

Explains the automatic defrost operation when the unit stops in heating mode.

VARIOUS PROTECTIONS

Covers protections like discharge gas temperature overrise and current release control.

TROUBLE SHOOTING

Unit Not Operating

Addresses issues when the unit fails to start or lights do not illuminate.

Self Diagnosis Function

Explains how to use the self-diagnosis function and interpret error codes.

Trouble Shooting Methods

Outlines diagnostic procedures including serial signal and IPM checks.

APPENDING DATA

Jumper and DIP Switch Settings

Explains jumper settings for indoor and outdoor units, including custom codes.

Pressure and Current Curves

Provides graphs of outdoor unit pressure and current vs. temperature.

Thermistor Resistance Values

Lists resistance values for various thermistors at different temperatures.

Capacity and Input Data

Shows capacity and input data charts for heating and cooling modes.

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Table of Contents