LG DR1F9H Service Manual

The LG DR1F9H is a high-performance home appliance requiring professional service and maintenance. This service manual provides comprehensive technical information for qualified technicians, including safety procedures, technical specifications, disassembly instructions, troubleshooting guides, and replacement part information. Below are key sections for proper servicing and maintenance.

Safety Precautions

Critical safety information for service technicians. Always follow these procedures to prevent injury and equipment damage.

Hazard Type	Precaution
Electrical Shock	Disconnect power before servicing; discharge capacitors
High Temperature	Allow components to cool before handling
Sharp Edges	Wear protective gloves during disassembly
Chemical Exposure	Use proper ventilation when handling refrigerants
Heavy Components	Use lifting equipment for parts over 50 lbs

WARNING! Only qualified technicians should perform service procedures. Always verify power is disconnected before beginning work.

Technical Specifications

Complete technical data for the LG DR1F9H unit.

• Model: DR1F9H
• Power Requirements: 120V AC, 60Hz, 15A
• Operating Pressure: 150-300 PSI
• Refrigerant Type: R-410A
• Weight: 185 lbs
• Dimensions: 36" H x 24" W x 28" D
• Compressor Type: Rotary Inverter
• Maximum Amperage: 12.5A
• Operating Temperature Range: 40°F to 115°F

Component Identification

Major components and their locations within the unit.

Component	Location	Function
Main Control Board	Upper rear panel	System operation control
Compressor	Bottom compartment	Refrigerant circulation
Condenser Coil	Rear section	Heat dissipation
Evaporator Coil	Front section	Cooling process
Expansion Valve	Left side near evaporator	Refrigerant pressure control
Fan Motor	Top section	Air circulation
Thermostat Sensor	Evaporator inlet	Temperature monitoring

Disassembly Procedures

Step-by-step instructions for safe unit disassembly.

1. Disconnect power and discharge capacitors.
2. Remove outer casing screws (12 total).
3. Carefully lift top cover and set aside.
4. Remove front panel clips (6 locations).
5. Disconnect electrical connectors from control board.
6. Remove compressor mounting bolts (4 bolts).
7. Extract compressor with proper lifting equipment.

CAUTION! Label all connections and take photos during disassembly for proper reassembly.

Electrical Schematics

Complete wiring diagrams and circuit descriptions.

• Main Power Circuit: 120V input through 15A fuse
• Control Circuit: 24V DC for board operation
• Compressor Circuit: 3-phase inverter drive
• Sensor Circuit: Thermistor inputs to main board
• Fan Motor Circuit: Variable speed control

Refer to schematic diagram DR1F9H-SCH-01 for detailed wiring connections and component values.

Troubleshooting Flowcharts

Systematic approach to diagnosing common issues.

Symptom	Diagnostic Step	Test Procedure
Unit not starting	Check power supply	Verify 120V at input terminals
Poor cooling	Check refrigerant pressure	Measure high/low side pressures
Unusual noises	Inspect compressor and fans	Listen for bearing noise
Error codes displayed	Check service manual codes	Refer to error code chart
Compressor short cycling	Check thermostat and sensors	Measure sensor resistance

Replacement Parts List

Genuine LG replacement parts with part numbers.

Part Number	Description	Quantity
DR1F9H-MCB-01	Main Control Board	1
DR1F9H-COMP-01	Compressor Assembly	1
DR1F9H-FAN-01	Fan Motor	2
DR1F9H-COIL-01	Evaporator Coil	1
DR1F9H-VALVE-01	Expansion Valve	1
DR1F9H-SENSOR-01	Temperature Sensor	3

Test Procedures

Verification tests after service completion.

1. Leak test: Apply 300 PSI nitrogen and check for pressure drop.
2. Electrical test: Verify proper voltage at all test points.
3. Performance test: Run unit through complete cycle.
4. Safety test: Verify all safety switches function properly.
5. Final inspection: Check for proper assembly and operation.

IMPORTANT: Document all test results in service records.

Reassembly Instructions

Proper reassembly following service procedures.

1. Install compressor with new mounting hardware.
2. Reconnect all electrical connections per schematic.
3. Replace filters and clean components as needed.
4. Reinstall panels in reverse order of removal.
5. Torque all fasteners to specified values.
6. Recharge system with specified refrigerant amount.

NOTE: Use new gaskets and seals during reassembly.

Calibration Procedures

Calibration steps for optimal performance.

• Temperature Calibration: Adjust thermostat offset if needed
• Pressure Calibration: Verify transducer readings
• Fan Speed Calibration: Set proper airflow rates
• Sensor Calibration: Verify temperature accuracy
• Control Calibration: Set proper operating parameters

Service Codes & Diagnostics

Complete list of error codes and diagnostic procedures.

Error Code	Description	Resolution
E1	High pressure fault	Check condenser and fan operation
E2	Low pressure fault	Check for leaks and refrigerant charge
E3	Sensor fault	Check sensor connections and values
E4	Communication error	Check wiring between boards
E5	Compressor overload	Check compressor windings and current

Service Support: 1-800-LG-SERVICE; www.lgservice.com