Air conditioning
158 Field cases
- Unit Completely Inoperative
- Various Abnormal Noises During Operation
- Water Dripping from Indoor Unit / Poor Drainage
- Foul Odor When Unit Operates
- Inverter PCB IGBT Module Burnout (E6/H6 Error)
- BLDC Outdoor Fan Motor Burnout (Bearing Wear → Overcurrent Trip)
- PFC Circuit Electrolytic Capacitor Swelling (Increased Ripple Current → Capacitance Drop)
- Outdoor Fan Blade Crack/Break (Vibration → Shaft Imbalance → Motor Bearing Damage)
- Reduced Cooling Capacity — Unit runs but fails to cool adequately
- Frozen Evaporator — indoor coil blocked by ice buildup
- Outdoor Unit PCB Short Circuit from Moisture Ingress — Rainwater Entry, Damaged Waterproof Cover
- Infrared Remote Not Responding — pressing buttons causes no AC response
- Wi-Fi Remote App Connection Failure — smartphone app cannot find AC unit
- Indoor Unit Drain Backflow — water dripping from indoor unit onto floor or walls
- Flare Joint Refrigerant Leak — refrigerant leaking at pipe connection
- Indoor Unit Outlet Condensation → Ceiling Stains
- Multi-Split Distributor Pipe Sizing Imbalance → Capacity Deviation in Some Indoor Units
- Duct Leakage Exceeding 15% → Reduced Delivered Capacity
- Duct Internal Condensation → Insulation Delamination → Ceiling Water Leak
- Inverter Overcurrent Error (Excessive Compressor Load)
- Inverter Error Code — Refer to Manufacturer Manual
- Inverter Instability from Pressure Abnormality
- Inverter Malfunction from Unstable Supply Voltage
- Inverter Overheating from Fouled Heat Sink
- Inverter Overheating from Overload Operation
- Drain Clog — Condensate Overflow / Indoor Unit Leak
- Condensate Pump Failure — Motor, Float, Control
- Insufficient Drain Slope or Reverse Slope — Gravity Drainage Fails
- External Condensation on Drain Line — Insufficient Insulation
- AC New Install — Evacuation and Vacuum Decay Test Procedure
- AC New Install — Flaring and Torque Tightening Procedure
- AC New Install — Nitrogen Pressure Leak Test (Low/High Side)
- AC New Install — Refrigerant Charging by Weight (R-32/R-410A)
- AC New Install — Refrigerant Line Insulation and Condensation Prevention
- AC New Install — Power Wiring (Single-Phase, Three-Phase, Dedicated Breaker)
- AC New Install — Indoor/Outdoor Communication Cable (Shield, EMI)
- AC New Install — Indoor Wall Mounting (Concrete, Drywall, Anchor Torque)
- AC New Install — Outdoor Unit Mounting (Ground, Wall Bracket, Rooftop)
- AC New Install — Condensate Drain Slope and Trap
- AC New Install — Outdoor Unit Clearance and Airflow Space
- AC Weak Cooling — Comprehensive Diagnosis (Filter, Coil, Refrigerant, Airflow)
- AC Completely Inoperative — Power, Breaker, Compressor, PCB Diagnosis
- AC Weak Cooling — Filter Clog (Most Common Cause)
- AC New Install — Refrigerant Line Routing (Bending, Traps, Oil Return)
- AC New Install — Line Set Length and Height Limit (Manufacturer Manual)
- AC New Install — Commissioning Checklist (ENERGY STAR / Korean KS)
- AC New Install — Pre-Charge / Purge / Service Valve Opening
- AC Intermittent Cooling — Repeated Auto ON/OFF (Short Cycling)
- AC Cooling Fault — Electronic Expansion Valve (EEV) Failure
- AC Weak Cooling — Outdoor Fan Stopped / Slow Speed
- AC Stops Immediately After Start — Protection Circuit Trip
- AC — Uneven Cooling Left/Right or Floor-by-Floor
- AC — Warm Air from Discharge / No Cooling Function
- AC Cooling Fault — Non-Condensable Gas (Air/Moisture) Contamination
- AC Indoor Coil Frost — Insufficient Airflow / Undercharge
- AC Weak Cooling — Outdoor Condenser Coil Fouling
- AC Indoor Unit Water Drip — Condensate Leak Diagnosis
- AC Drain Pump Fault — Forced Condensate Discharge Failure
- AC Drain Pipe Clog — Slime / Debris Removal
- AC Condensate Overflow — Auxiliary Pan or Ceiling Leak
- AC Outdoor Unit Leak — Condensation, Rain, or Drain Hose Failure
- AC Drain Pipe Freeze — Winter Drainage Failure
- AC Drain Trap Issue — Negative Pressure Loss / Odor Backflow
- AC Drain / Refrigerant Pipe Sweating — Inadequate Insulation
- AC PCB (Main Board) Fault — Diagnosis and Replacement
- AC Temperature Sensor (Thermistor) Failure
- AC Communication Error — Indoor/Outdoor Signal Failure (E-code)
- AC Remote Control No Response — Battery, IR, Signal Diagnosis
- AC Inverter Trip — Current / Temperature Protection
- AC Pressure Sensor (High/Low) Fault
- AC Compressor Overload — Thermal / Current Protection
- AC Capacitor Fault — Start / Run Capacitor Diagnosis
- AC Relay Fault — Contact Wear / Coil Open
- AC Indoor Unit Noise / Vibration — Blower, Blade, Cabinet Check
- AC Outdoor Noise / Vibration — Top Cause of Neighbor Complaints
- AC Compressor Knock / Metallic Sound — Liquid Slug / Mechanical Fault
- AC Fan Imbalance — Vibration / Noise on Rotation
- AC Refrigerant Flow Noise — Shhh / Hiss / Water-Like Sound
- AC Blower Belt Noise — Package / Ducted Systems
- AC Evaporator Frost/Defrost 'Pop' Sound
- AC Refrigerant Recovery Procedure (EPA 608 / Korean MOE Certified)
- AC R-32 Leak Response — A2L Safety Procedure
- R-22 System Retrofit to R-407C / R-422D Alternatives
- R-454B Transition — Next-Gen R-410A Replacement
- AC Cooling Season Pre-Start Check — Mandatory Items
- Heat Pump Heating Season Check — Defrost, Outdoor Condensate, Heat Trace
- AC Annual Leak Check — F-Gas Regulation Compliance
- AC Warranty / Maintenance Record — Digital Logging Required
- AC Compressor Lockout — Inverter Won't Start (LG CH21 / Samsung E311)
- Heat Pump 4-Way Valve Stuck — Mode Switch Fails (Samsung E311–E320)
- Field Purge Procedure — Tech Practice (Shortcut vs Vacuum Standard)
- Outdoor Unit Vibration / Noise Emergency — Case Tapping, Pads, Cable Ties
- LG AC CH Error Code Master — CH01–CH07 Field Diagnosis
- Samsung AC E/C Error Code Master — E101/E102/E121/E122/E151/E152
- EEV Stepping Motor Diagnosis — Coil Resistance, Back-EMF, Signal Check
- Comm Line L/N Swapped — #1 Cause of Communication Faults
- PCB Inverter Board Burn-out — Capacitor / IPM / Driver Fault
- NTC Temp Sensor Diagnosis & Replacement — 10kΩ @25°C + B-Constant Match
- Megger Insulation Resistance Test — Compressor / Motor / Breaker Safety
- Outdoor Fan Motor Bearing Replacement — Grinding Sound / Rotational Friction
- System AC Drain Pump Cleaning / Replacement — Ceiling Leak Emergency
- AC Pre-Season Checkup — 11-Item Tech Standard Checklist
- Standard Vacuum Procedure — −100.7 kPa (5 torr), 2.5h Pump, 1h Hold
- Capacitor μF Measurement — LCR Meter / Multimeter Capacitance Mode
- Evaporator Frost Diagnosis — 4 Causes (Undercharge / Overcharge / Airflow / Compressor)
- Refrigerant Leak Detection — Soap Bubble / Electronic / Tracer Gas / UV Dye
- R-32 Leak Safety Response — A2L Flammability Emergency Procedure
- AC Commissioning Report / Handover — Standard Form + Photos / Measurements
- Electrical Work Safety — LOTO (Lockout/Tagout) + Insulation PPE
- Flare Leak Emergency Fix — Cut, Re-Flare, Torque
- Refrigerant Mixing Prohibited — R-22 / R-410A / R-32 / R-454B Compatibility
- Coil Cleaning Chemical Safety — Neutral / Alkaline / Acidic Selection
- AC Warranty Claim Process — Coverage / Exclusions / Evidence
- AC Pre-Installation Site Survey — 8-Item Checklist + Quote
- PCB Killed by Lightning/Surge — SPD Install & Protection
- Post-Install Commissioning — 10-min Run, Pressure, ΔT Check
- AC Capacity Shortage — Install vs Leak vs Coil Blockage Diagnosis
- Outdoor Unit Sun Shielding — Efficiency & Compressor Protection
- Inverter vs Fixed-Speed — Diagnosis Priority Differences
- Refrigerant Recovery — No Venting, Use Recovery Machine
- 3-Phase Wiring Reversal — Compressor Rotation Check
- User Self-Check Card — 5 Steps Before Service Call
- VRF/Multi System — One Indoor Not Working (Addressing/Comm)
- Condensate Pump Noise & Failure — Vibration/Backflow/Diagnosis
- Flare vs Brazing — Field Selection Criteria
- Bird Nest / Wasp Nest in Outdoor Unit — Safe Removal & Prevention
- Outdoor Cabinet Resonance — Low-Speed Vibration/Noise Fix
- Handling Elderly Customers — Explanation/Demo/Paperwork
- Night/Quiet Mode Malfunction — User Reports & Diagnosis
- Rooftop Install Safety — Harness/Anchor/Fall Prevention
- Pipe Length Extra Charge — g/m Calc Beyond 7m
- Indoor Unit Water Leak — 5 Causes (Drain/Level/Insulation)
- BLDC Fan Motor Replacement — Inverter Outdoor Precision Diagnosis
- AC Tech Essential 30 Tools + Price Guide
- Receipt & Tax Invoice — Sole Proprietor Procedure
- Customer Complaint Script — 5-Step Dispute Prevention
- Self-Install vs Manufacturer Warranty — Dispute Avoidance
- R-32 Charging Procedure — A2L Safety, Ventilation, Ignition Source
- Condenser/Evaporator Fin Straightening — Comb & Compressed Air
- Indoor Mold/Smell Removal — Chemical Clean + UV-C Sanitize
- Setpoint ≠ Actual Temp — Control Algorithm Explained
- Window vs Split AC — Selection for Older Korean Homes
- 5 Power-Saving Myths — Customer Response
- Tropical Night Operation Strategy — When 25°C+ Disrupts Sleep
- Extreme Cold Defrost — Outdoor Heating Mode <-15°C
- R-22 Legacy Systems — Repair vs Replace Decision
- Sizing AC BTU by Room — Measure + Correction Factors
- Install Handover — 15-Photo Checklist
- On-Site Energy Audit — Current/Power/Run-Time Measurement
- Extended Warranty & Maintenance Package — Tech Revenue Model
- LG ThinQ / Samsung SmartThings Diag Mode — Remote 1st Diagnosis
- System Replacement Timing — 10-yr vs 15-yr Decision
- Cleaning Tool Sanitation — Prevent Cross-House Mold Transfer
- Water Hammer / Flare Leak — Vibration & Pulsating Pressure
- Multi-Split Load Balancing — 4+ Indoor Unit Optimization
- Pre-Season Marketing — Apr-May Booking Campaign
- Ceiling Cassette Install — Shops/Offices 4-Way Airflow
- Pet Household — Filter Management, Shorter Cleaning Cycle