Lesson 1Parts selection and sourcing: identifying OEM vs compatible parts, reading part numbers and spec sheetsDevelop skills to identify correct replacement parts using model tags, OEM catalogs, and spec sheets, compare OEM and aftermarket options, verify electrical and mechanical compatibility, and avoid common ordering and substitution mistakes.
Locating and decoding appliance model tagsReading OEM part numbers and revisionsUsing exploded views and parts diagramsComparing OEM and aftermarket componentsVerifying electrical and mechanical compatibilityLesson 2Compressor and relay testing: start relay/capacitor diagnosis, amp draw testing, locked rotor identificationLearn how to test refrigerator compressors and start components using meters and clamp ammeters, identify failed relays and capacitors, recognize locked-rotor conditions, and decide when a compressor is electrically or mechanically beyond repair.
Identifying compressor terminals and winding layoutTesting PTC and mechanical start relaysStart and run capacitor inspection and testsMeasuring compressor amp draw and LRADiagnosing locked rotor and internal shortsLesson 3Customer communication scripts: simple explanation of cause, recommended repairs vs replacement, cost/benefit and maintenance tips to prevent recurrenceBuild clear, professional communication habits with customers by explaining faults in simple language, presenting repair versus replacement options, estimating costs, and offering maintenance tips that reduce future breakdowns and callbacks.
Explaining diagnosis in non-technical termsDiscussing repair versus replacement choicesPresenting written estimates and optionsSetting realistic timelines and outcomesProviding preventive maintenance adviceLesson 4Electrical and sensor tests: multimeter checks for continuity/resistance of defrost heater, thermistor testing, fan motor current drawPractice safe electrical diagnostics using a multimeter and clamp meter to check continuity, resistance, and current draw on defrost heaters, thermistors, fan motors, and wiring, distinguishing normal readings from open, shorted, or drifting components.
Multimeter safety and test lead setupContinuity and resistance checks on heatersThermistor resistance versus temperature chartsFan motor voltage and current measurementsTesting door switches and harness connectionsLesson 5Interpreting symptoms: warm fresh food, cold freezer with back-wall ice, continuous compressor operationLearn to interpret common refrigerator symptoms such as warm fresh food, icy back walls, noisy or continuous running, and intermittent cooling, then map each pattern to likely airflow, defrost, control, or sealed system issues.
Warm fresh food, normal freezer analysisBack-wall ice and airflow restriction cluesContinuous or near-continuous run-timeShort cycling and frequent startsNoises, vibrations, and rattlesIntermittent cooling and nuisance tripsLesson 6Common faults: compressor, evaporator frost/defrost system, evaporator fan, temperature sensors, thermostats, and refrigerant leaksConnect typical refrigerator symptoms to likely failed components, including compressor problems, evaporator frost issues, fan failures, sensor errors, and refrigerant leaks, and learn to prioritize tests that confirm or rule out each suspected fault.
No cool or warm cabinet in both sectionsWarm fresh food, cold or icy freezerShort cycling and long run-time issuesNoisy operation and vibration complaintsIntermittent cooling and nuisance tripsSigns suggesting sealed system leaksLesson 7Thermodynamics of domestic refrigeration systems and airflow patternsUnderstand how heat moves in domestic refrigerators, including pressure–temperature relationships, evaporator and condenser roles, and cabinet airflow patterns, so you can link poor cooling, icing, and short cycling to specific thermodynamic faults.
Basic refrigeration cycle and key componentsPressure–temperature relationship in systemsEvaporator loading and frost formationCondenser heat rejection and ambient effectsAirflow paths in fresh food and freezerImpact of door openings and loadingLesson 8Repair procedures: replacing defrost heater, thermistor, evaporator fan, door gasket; steps to recover/recharge refrigerant (scope and contractor decision)Study step-by-step repair procedures for common failures, including replacing defrost heaters, thermistors, evaporator fans, and door gaskets, and understand when refrigerant recovery or recharge must be referred to licensed contractors.
Safe disassembly and panel removalReplacing defrost heaters and wiringThermistor access, testing, and replacementEvaporator and condenser fan replacementDoor gasket removal and installationScope limits for sealed system repairsLesson 9Safety procedures: electrical isolation, refrigerant handling regs, PPE, pressure relief and recovery basicsApply essential safety practices for refrigerator service, including electrical isolation, lockout habits, PPE selection, safe handling of sharp metal and moving parts, and understanding basic refrigerant safety and regulatory responsibilities.
Lockout, tagout, and unplugging routinesVerifying absence of voltage before workPPE for electrical and sharp-edge hazardsSafe handling of fans and moving partsBasics of refrigerant exposure risksRecordkeeping and regulatory dutiesLesson 10Defrost system diagnostic plan: timer, bi-metal/thermostat, defrost heater, control board checksFollow a stepwise plan to diagnose defrost system faults by testing timers or control boards, defrost heaters, bi-metal thermostats, and sensors, distinguishing between electrical failures and control logic issues that cause evaporator icing.
Recognizing symptoms of defrost failureLocating defrost components by designTesting defrost heaters for continuityChecking bi-metal and defrost thermostatsForcing defrost mode from control boardInterpreting timer and control board faultsLesson 11Visual inspection checklist: seals, door alignment, ice buildup, drain and defrost heater areasUse a structured visual checklist to quickly spot common refrigerator issues, including gasket leaks, door misalignment, ice buildup, blocked drains, damaged wiring, and dirty condensers, reducing callbacks and guiding deeper diagnostic testing.
Inspecting door gaskets and sealing surfacesChecking door alignment and hinge wearIdentifying ice buildup and airflow blockagesExamining drain pan, tube, and outletsInspecting wiring, connectors, and insulationLesson 12Refrigerant system checks: static pressure readings, leak detection methods, when to call certified refrigerant technicianLearn how to perform basic sealed system checks within legal limits, including static and running pressure readings, temperature split observations, simple leak detection methods, and recognizing when to stop and call a certified refrigerant technician.
Recognizing sealed system componentsSafe use of service ports and gaugesStatic and running pressure interpretationTemperature split and line frost patternsNon-invasive leak detection techniquesWhen to involve certified techniciansLesson 13Post-repair tests and verification: temperature stabilization testing, run-time monitoring, sealing and airflow validationVerify successful repairs by monitoring cabinet temperatures, run-time, and defrost performance, checking door seals and airflow, and documenting readings so you can confidently close the job and reduce the risk of callbacks or repeat failures.
Stabilization time and temperature loggingChecking thermostat and sensor responseMonitoring compressor and fan run-timeVerifying door seal and light operationConfirming defrost cycle performanceFinal documentation and customer sign-off
