AC Fridge Repairing Course

Lesson 1 • The Vapour Compression Cycle

This traces refrigerant through all four cycle stages: compression, condensation, expansion, evaporation. This builds the mental model used throughout the course.

Lesson 2 • Refrigerant Safety and Handling

This covers refrigerant toxicity, flammability classes, and proper recovery procedures per environmental regulations. This prepares students for compliant field work.

Lesson 3 • Basic Thermodynamics for Technicians

This covers heat transfer modes, latent vs. sensible heat, and the refrigeration effect. This anchors all subsequent component and cycle analysis.

Lesson 4 • Tools and Test Equipment Overview

This identifies hand tools, manifold gauge sets, multimeters, and leak detectors used throughout the course. Students match each tool to its diagnostic purpose.

Lesson 1 • Expansion Devices

This covers capillary tubes, thermostatic expansion valves, and electronic expansion valves. Students select the correct device for a given system configuration.

Lesson 2 • Electrical Components and Controls

This identifies thermostats, start relays, overload protectors, capacitors, and fan motors. This links each component to its role in system start-up and protection.

Lesson 3 • Condensers and Evaporators

This distinguishes air-cooled and wire-on-tube condenser designs and frost-free vs. static evaporators. This explains how coil condition affects system performance.

Lesson 4 • Compressor Types and Functions

This examines reciprocating, rotary, and scroll compressors found in domestic appliances. This connects compressor type to expected performance and failure modes.

Lesson 1 • AC Unit Wiring and PCB Layouts

This covers split AC indoor/outdoor unit wiring, PCB terminal identification, and communication signal lines. Students connect diagrams to physical board inspection.

Lesson 2 • Pictorial Wiring Diagrams

This teaches how to read colour-coded pictorial diagrams showing physical wire routing. This bridges the gap between schematic logic and actual appliance wiring.

Lesson 3 • Ladder Diagram Interpretation

This explains power rails, rungs, and load placement in ladder logic. Students trace current paths to determine which components energize under given conditions.

Lesson 4 • Defrost and Control Circuit Analysis

This focuses on defrost timers, defrost heaters, and thermistor-based control circuits common in frost-free refrigerators. This prepares students for defrost fault diagnosis.

Lesson 1 • Symptom-Based Diagnostic Approach

This introduces a structured symptom-to-cause diagnostic framework. This prevents random part replacement by teaching logical elimination of fault possibilities.

Lesson 2 • Interpreting Error Codes and Sensors

This decodes manufacturer error codes and tests thermistors, pressure switches, and flow sensors. This connects sensor data to control board fault logic.

Lesson 3 • Refrigerant Leak Detection

This applies electronic detectors, UV dye, and soap bubble methods to locate leaks. Students select the appropriate method based on system type and leak severity.

Lesson 4 • Manifold Gauge Set Diagnostics

This teaches correct gauge connection, reading high/low side pressures, and interpreting abnormal pressure patterns. This links pressure readings to specific system faults.

Lesson 1 • Door Gasket and Mechanical Repairs

This addresses gasket replacement, door alignment, condenser fan motor swap, and drain line clearing. This covers high-frequency low-complexity repairs that maximise shop throughput.

Lesson 2 • Thermostat and Control Board Repair

This guides replacement of mechanical thermostats and electronic control boards with correct calibration. This ensures accurate temperature control post-repair.

Lesson 3 • Compressor Replacement Procedure

This details safe refrigerant recovery, compressor removal, and installation with correct oil charge. Students perform a complete swap on a practice unit.

Lesson 4 • Sealed System Leak Repair

This teaches brazing techniques, leak repair on copper tubing, and recharging the sealed system. Students practice on scrap tubing before live system work.

Lesson 1 • Capacitor and Relay Replacement

This identifies failed run/start capacitors and relays as the most common window AC electrical fault. Students test, source, and replace components correctly.

Lesson 2 • Cleaning, Reassembly, and Testing

This details coil cleaning, drain pan treatment, reassembly torque sequence, and final performance test. This ensures unit leaves the shop in optimal condition.

Lesson 3 • Fan Motor and Blade Service

This covers dual-shaft fan motor testing, blade removal, and motor replacement. Correct blade pitch and balance prevent vibration and noise complaints.

Lesson 4 • Window AC Disassembly and Inspection

This covers safe removal from wall sleeve, panel disassembly sequence, and initial inspection checklist. This establishes correct disassembly habits before any repair.

Lesson 1 • Indoor Unit Repairs

This covers blower wheel cleaning, evaporator coil leak repair, drain pump replacement, and louver motor service. This addresses the most frequent indoor unit complaints.

Lesson 2 • Line Set Installation and Leak Testing

This teaches flaring, brazing, and pressure testing refrigerant line sets for new installations and repairs. Correct line set work prevents future refrigerant loss.

Lesson 3 • Split System Architecture Review

This maps refrigerant and electrical connections between indoor and outdoor units. This establishes the system-level view needed before component-level repair.

Lesson 4 • Inverter Compressor Diagnostics

This explains variable-frequency drive operation and inverter board testing. Students distinguish inverter faults from compressor mechanical failures.

Lesson 1 • Intermittent Fault Diagnosis

This addresses faults that appear only under specific load or temperature conditions. Students use data logging and stress testing to reproduce and confirm intermittent failures.

Lesson 2 • Multi-Fault and Cascade Failures

This teaches recognition of cascade failures where one fault damages secondary components. Students avoid incomplete repairs that return as repeat callbacks.

Lesson 3 • Preventive Maintenance Procedures

This defines scheduled maintenance tasks that extend appliance life and reduce emergency calls. Students build a maintenance service offering for recurring revenue.

Lesson 4 • Repair Documentation and Warranty

This covers job card completion, parts traceability, and warranty claim documentation. This protects the technician and business from liability disputes.