Mitsubishi Electric PK24FK

Questions and Answers

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Ryan JonesAug 8, 2025
What to do if check code 'EO' appears on Mitsubishi Electric Air Conditioner when remote controller power button is turned on?
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  michaelmooreAug 8, 2025
  If the check code 'EO' appears on your Mitsubishi Electric Air Conditioner when you turn on the remote controller, it may indicate a signal transmission error between the indoor unit and the remote controller. To address this, connect a sub remote controller and turn the circuit breaker ON. If the 'centrally controlled' display remains, replace the indoor controller board. If the display disappears, turn the remote controller POWER button ON and check as follows.
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Ruth ClarkAug 15, 2025
Why Mitsubishi Electric Air Conditioner remote controller display does not appear when turning power button on?
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  Larry Eaton Jr.Aug 15, 2025
  If the Mitsubishi Electric Air Conditioner remote controller display doesn't appear when you turn the power on, it could be due to several reasons. It might be a damaged remote controller, a short circuit in the transmission wire, bad contact at indoor CN40, CN40 being attached to a sub unit, a damaged transformer, bad contact at CN4T, a blown fuse, or the circuit breaker being OFF. First, measure the voltage between the terminals of the remote controller. If there's no voltage, remove the terminals and measure the voltage between the wires. If the voltage is between 6VDC and 12V, replace the remote controller. Check each of the points mentioned. If none are defective, then replace the indoor controller board.
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sharonjonesAug 25, 2025
What to do if Mitsubishi Electric PK24FK operating display appears and disappears quickly when remote controller power button is turned on?
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  matthewdiazAug 25, 2025
  If the operating display on your Mitsubishi Electric Air Conditioner appears briefly and then disappears when you turn the remote controller power button on, the issue could stem from a few things: a short circuit in the indoor/outdoor connecting wire, a short circuit in the transmission wire, a short circuit in the drain sensor heater circuit, or incorrect remote controller operation due to noise from other appliances. Check the wiring. Measure the resistance of the drain sensor connector CN50; normal resistance should be 82?. Turn the circuit breaker OFF, and then turn it back ON. If the remote controller remains abnormal after these steps, replace the indoor controller board.
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Aaron MitchellDec 1, 2025
How to fix 'CENTRALLY CONTROLLED' display that does not disappear on Mitsubishi Electric PK24FK remote controller?
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  Amy KimDec 1, 2025
  If the 'CENTRALLY CONTROLLED' display remains on your Mitsubishi Electric Air Conditioner remote controller, there are a few potential causes. It could be due to a wrong address setting of the remote controller or indoor controller board, a timer adapter connected to the remote controller, or a signal transmission error between the indoor unit and the remote controller. First, check the address setting of the remote controller and indoor controller. Ensure the timer adapter is used correctly. Try turning another remote controller’s DIP SW17-7 ON to make it a sub controller. Connect the sub controller to the unit, and turn the circuit breaker ON. If the 'centrally controlled' display disappears, replace the original remote controller. If the display remains, replace the indoor controller bo...

Summary

Features of the PK Series Air Conditioners

Compact Design Highlights

Highlights the reduced wall space required for the PK series air conditioners.

Noise Suppression and Comfort Enhancements

Details improvements in low-noise operation and airflow resistance for enhanced comfort.

Automatic Flap Shutter Functionality

Explains the auto flap shutter's role in closing the air outlet and adjusting airflow angle.

Flexible Installation Adaptability

Covers aspects like external piping, multi-directional piping, and ease of installation.

Advanced Microprocessor System

Ultra-Thin Remote Controller Design

Describes the streamlined, square remote controller designed for blendability with interiors.

Remote Controller LCD Display Features

Explains the visual display of operation modes, temperature, fan speed, and more.

Convenient 24-Hour Programmable Timer

Details the functionality of the timer for automatic unit operation scheduling.

Instant Fault Diagnosis Capability

Explains how the unit indicates faults via a self-diagnostic feature on the LCD.

Memory Feature for Storing Settings

Describes the unit's ability to memorize previous settings for consistent control.

Non-Polar Two-Wire Remote Controller Cables

Details the benefits of the slim, two-wire cable for remote controller installation.

Automatic Cooling and Heating Changeover

Explains the system that automatically switches between cooling and heating based on room temperature.

Pre-Charged Refrigerant System

High Reliability and Easy Servicing Aspects

Technical Specifications Overview

Data and Performance Information

Cooling Capacity Performance Details

Details cooling capacity based on indoor/outdoor air conditions and airflow.

Cooling Capacity Correction Factors

Provides correction factors for cooling capacity based on refrigerant piping length.

Cooling Performance Curves

Operating Range Specifications

Power Supply Requirements

Specifies the rating and allowable voltage ranges for indoor and outdoor units.

Operational Temperature and Humidity Ranges

Details the operating conditions for temperature and humidity for cooling.

Outline and Dimensions

Indoor Unit PK12 FK Dimensions

Provides detailed dimensional drawings and mounting information for the PK12FK indoor unit.

Outdoor Unit PU12 EK1 Dimensions

Shows dimensional drawings and installation considerations for the PU12EK1 outdoor unit.

Outdoor Unit PU18 EK1 Dimensions

Provides dimensional drawings and installation details for the PU18EK1 outdoor unit.

Outdoor Units PU24;30 EK1 Dimensions

Details the dimensions and installation aspects for the PU24/30EK1 outdoor units.

Outdoor Unit PU36 EK1 Dimensions

Shows dimensional drawings and installation information for the PU36EK1 outdoor unit.

Remote Controller Dimensions

Presents dimensional drawings for the remote controller, including mounting details.

Refrigerant System Diagram

Wiring Diagrams

Indoor Unit PK12 FK Wiring Diagram

Shows the electrical connections and components for the PK12FK indoor unit.

Outdoor Unit PU12;18 EK1 Wiring Diagram

Details the electrical wiring and connections for PU12/18EK1 outdoor units.

Outdoor Units PU24;30;36 EK1 Wiring Diagram

Presents the wiring diagrams for PU24/30/36EK1 outdoor units.

Operation Flow-Charts

Main Operation Logic

Illustrates the primary operational sequence and decision points of the air conditioner.

Cooling Operation Sequence

Details the step-by-step process and conditions for cooling mode operation.

Dry Operation Sequence

Outlines the sequence of operations and control logic for the dry mode.

Microprocessor Control System

Microprocessor Control System Overview

Explains the system architecture and communication flow between units and controllers.

Microprocessor Cooling Operation Control

Covers thermostat function, coil frost prevention, and outdoor unit abnormality detection.

Microprocessor Dry Operation Control

Details thermostat function, compressor control, and fan control during dry operation.

Remote Control Operation and LCD

Remote Control ON;OFF Operation

Describes how to turn the unit on and off using the remote control's power button.

Mode Selection via Remote Control

Details how to select operating modes like COOL, DRY, or FAN using remote control buttons.

Temperature Adjustment with Remote

Explains how to set the desired temperature using the WARMER and COOLER buttons.

Timer Functions on Remote Control

Covers setting ON/OFF timers and setback operations using the remote controller.

Fan Speed Control via Remote

Explains how to adjust the fan speed between LOW and HIGH using the remote control.

Remote Self-Diagnostic Function

Details how to activate and interpret the self-diagnostic function via the remote controller.

Remote Test Run Mode Operation

Explains how to initiate and use the test run mode from the remote controller.

Test Run Function Procedures

Pre-Operation Checks for Test Run

Covers checks required before performing the test run operation, including installation and wiring.

Performing Test Run Operation Steps

Provides step-by-step instructions on how to activate and use the test run function.

Emergency Operation Procedures

Pre-Operation Checks for Emergency Mode

Details checks required before enabling emergency operation, ensuring normal compressor and fan function.

Activating Emergency Operation Mode

Explains how to enable and use the emergency operation mode via dip switch settings.

Dip Switch and Jumper Connector Functions

Remote Controller Board Settings

Describes the functions of SW17 address selector and system backup switch.

Indoor Controller Board Settings

Details SW1 mode selector and other model-specific dip switches for indoor unit functions.

Indoor Controller DIP Switches (SW2-SW7)

Explains the function of SW2 address selector and other relevant switches.

Indoor Controller Jumper Connectors (J5)

Describes J5 for selecting heat pump models and its unavailability for PK-FK.

Outdoor Microprocessor Control

Outdoor Unit Protection Functions

Covers protection mechanisms like reversed phase, high pressure, and overcurrent detection.

Outdoor Coil Thermistor Control Logic

Explains how the outdoor coil thermistor controls fan speed and detects circuit issues.

Outdoor Unit Operation Control Methods

Details how the compressor receives signals from the indoor unit to start or stop.

Outdoor Fan Speed Control Mechanisms

Describes fan speed control based on outdoor coil temperature and fan output.

Initial Fan Speed Setting

Explains fan output settings upon power-on or compressor restart based on outdoor coil temperature.

Crankcase Heater Operation Control

Details the operation of the crankcase heater with and without jumper wire J3.

Fixed Fan Output Mode Activation

Explains how to fix the fan output speed and how to release this mode.

Outdoor Controller Board Switch Functions

Describes the functions of SW1, SW2, and SW3 switches on the outdoor controller board.

Power-On Reset State Operation

Details microprocessor operation during power-on-reset, including jumper wire functions.

100% Fan Output Configuration

Explains how to achieve 100% fan output by shorting CN22 and its conditions.

Time Shortening Functionality

Describes how shorting CN21 shortens various time delays like fan control period and time delays.

Troubleshooting Guide

Troubleshooting Test Run Issues

Addresses common problems encountered during test run operation and their causes.

Remote Self-Diagnostic Troubleshooting

Explains how to use the self-diagnostic function to identify and resolve malfunctions.

Outdoor Board Switch Service Data

Details how outdoor controller board switches and LEDs indicate service data and check codes.

Troubleshooting by Check Code

Lists check codes, diagnoses of malfunctions, and corresponding check points.

Outdoor Unit Not Working Troubleshooting

Addresses common causes and checks when the outdoor unit fails to operate.

Troubleshooting Wiring Errors

Identifies phenomena resulting from incorrect wiring between units and controllers.

Miscellaneous Troubles and Causes

Covers other common issues like vane problems, display errors, and power button failures.

System Control Configurations

System Control Options Overview

Describes different system control configurations: single remote, dual remote, individual, and multiple display.

Single Remote Group Control Setup

Explains how to control multiple units simultaneously with one remote controller.

Dual Remote Controller Operation Guide

Details how to use two remote controllers for unit control, including main/sub controller setup.

Remote ON;OFF and Individual Control Methods

Covers switch functions for controlling units remotely and individually.

Grouped Remote Control for Individual Units

Explains how to achieve individual unit control by grouping remote controllers.

Multiple Remote Control Display Installation

Describes the installation and wiring of a multiple remote control display adapter.

Disassembly Instructions

Indoor Unit PK24 FK Disassembly Guide

Step-by-step guide for disassembling the PK24FK indoor unit components.

Outdoor Unit PU18 EK Disassembly Guide

Provides instructions for disassembling the PU18EK outdoor unit, covering electrical and blower motor parts.

Outdoor Unit PU24 EK Disassembly Guide

Details the disassembly procedure for the PU24EK outdoor unit, including electrical and blower motor parts.

Parts Lists

Indoor Unit Structural Parts

Lists structural components for PK12FK and PK18-36FK indoor units with part numbers.

Indoor Unit Electrical Parts

Lists electrical components for PK12FK and PK18-36FK indoor units with part numbers and wiring symbols.

Outdoor Unit Structural Parts

Lists structural components for PU12/18EK1, PU24/30EK1, PU36EK1 outdoor units with part numbers.

Outdoor Unit Functional Parts

Diagrams and list of functional components for PU12/18EK1, PU24/30EK1, PU36EK1 outdoor units.

Optional Parts and Accessories

Optional Refrigerant Pipes

Details available optional refrigerant pipe kits for different models and lengths.

Timer Features and Adapters

Covers timer specifications, features, connection, and adapter information.

Timer Adapter for System Control

Describes the purpose and connection of the timer adapter (PAC-SA89TA-E).

Multiple Remote Controller Adapter

Details the adapter (PAC-SA88HA-E) for connecting multiple remote controllers.

Centralized Remote Controller Unit

Explains the functions and dimensions of the centralized remote controller (PAC-805RC).

Program Timer Adapter Connection Guide

Details the connection method and wiring for the program timer adapter (PAC-825AD).