LG Air Conditioner Error 45

⚡ Quick Answer: The LG air conditioner error code 45 indicates a potential drain pump failure, often accompanied by unusual noises and water accumulation around the u... ✅ DIY Fixable

What Does Error 45 Mean?

The LG air conditioner error code 45 indicates a potential drain pump failure, often accompanied by unusual noises and water accumulation around the unit. This error may also arise from communication faults with accessory modules or sensor issues related to temperature readings. Immediate attention is needed if the error persists or frequently recurs during operation.

Common Symptoms:

  • unit displays error code 45 or CH45 on the display
  • system operation may stop or be restricted

Possible Causes

  • Communication fault with optional accessory modules (low)
  • Sensor fault (variously reported as outdoor oil temperature sensor or capacitor temperature sensor) (low)

How to Fix Error 45

DIY Fix Basic checks and reset

  1. Turn off the air conditioner and disconnect from power
  2. Wait several minutes and reconnect power to perform a reset
  3. Observe if error returns

Technician Only Inspect accessory communications and sensor circuits

  1. Check communication lines between indoor unit and optional modules for continuity or faults
  2. Test relevant temperature sensors (outdoor oil or capacitor temp) for correct resistance and signal
  3. Repair or replace identified faulty modules or wiring

Parts needed: communication cables, optional accessory modules, temperature sensors

🛑 When to Call a Pro:
  • If error persists after basic reset
  • If error recurs frequently during operation
  • If you are unfamiliar with electrical diagnostics

Next step

Choose the next step for 45

Confirm the diagnosis before ordering. An error code can identify the system involved, but it does not prove that a specific part has failed.

Check during diagnosis

Most relevant component to inspect

Temperature Sensor

Monitors the internal temperature to ensure correct operation and prevent overheating.

Typical part-only price
$15 - $35
DIY difficulty
Easy
Estimated time
15-30 mins
Where can I find the model number?

Check the rating label around the door, lid, frame, rear panel, or inside the appliance cabinet. Use the complete model number, including suffixes.

Find a part that fits my model

Verify the complete model and part number on the retailer's compatibility page before ordering.

Other parts options

Check related components first; use model search as a fallback.

Model number required

Model-compatible Air Conditioner parts

Enter the complete model number to browse compatible replacement parts. This is a model-based parts search, not a diagnosis that a specific component failed.

Find a part that fits my model

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Optional routine care

Maintenance supplies

These products support cleaning or routine upkeep. They are separate from the possible repair components above and are not claimed to fix this error code or symptom.

Maintenance supply

Air Conditioner Fin Cleaner

For routine cleaning of accessible coil fins when permitted by the manufacturer. Disconnect power and follow product and appliance instructions.

View maintenance supply
Maintenance supply

Model-Compatible Washable AC Filter

A reusable filter option only where the appliance supports one. Match the full model, dimensions, and filter specification.

Compatibility check required: use the complete appliance model and compare the existing filter, bag, or specification before ordering.

Find one that fits my model

Affiliate disclosure: As an Amazon Associate I earn from qualifying purchases. Recommendations are based on routine-care relevance, not commission rate.

Technical Specifications

wattage 50W
component Drain Pump
resistance 5-15 ohms
part_number LG 4681A20001A
voltage_rating 115V AC

Common Questions

What does 45 error mean on lg air conditioner?

Error 45 indicates a drain pump failure, unusual noises, and possible water accumulation.

Can I fix lg air conditioner 45 error myself?

Yes, try resetting the unit by disconnecting it from power and reconnecting after a few minutes.

How much does it cost to fix 45 error?

Repair costs range from ¥5,000 to ¥30,000, depending on parts and region.

When should I call a technician for 45?

Call a technician if the error persists after a reset or if you are not familiar with electrical diagnostics.

Data last verified: 2026-07-26

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