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Error code reference

LG Air Conditioner Error Code E443

Operation prohibited due to low pressure

LG codesLG air conditioner codes
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What the E443 error code actually means

Your LG air conditioner detected that the refrigerant pressure inside the system was too low to safely start cooling, so it shut itself down to prevent damage to the compressor. This usually means the system has lost refrigerant due to a leak, or there is a problem with the sensor that monitors pressure. A certified technician will need to check the refrigerant level and inspect the system for leaks before the unit can operate again.

Diagnostic procedure

The full E443 procedure

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1
First diagnostic step
Check high pressure sensor connector; check for refrigerant leakage through manifold gauge.
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Most common causes of E443

Ranked by how often they cause this code
  1. 1Refrigerant leak
  2. 2Loose or damaged high pressure sensor connector
  3. 3Faulty high pressure sensor
  4. 4Severely restricted refrigerant flow
  5. 5Ambient temperature conditions

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Questions people ask about E443

What does E443 mean on a LG air_conditioner?
E443 means the unit detected a low pressure condition and the high-side refrigerant pressure did not reach the required standard before the air conditioning cycle could begin. As a safety measure, the control board prohibits compressor operation to prevent damage. The fault points to either a refrigerant loss in the system or a problem with the high pressure sensor or its wiring.
Is it safe to keep running my LG air conditioner when E443 appears?
No, you should not attempt to bypass or ignore this fault. The E443 lockout is a protective measure that prevents the compressor from running under unsafe pressure conditions. Operating the compressor with low refrigerant pressure can cause the compressor to overheat and fail, which is a much more expensive repair than addressing the underlying pressure issue.
Will resetting the LG air conditioner clear the E443 error code?
A power reset may temporarily clear the displayed code, but the fault will return as soon as the unit attempts to start and again fails to meet the required high-side pressure. Resetting without addressing the underlying cause does not fix the problem and risks repeated stress on system components. The root cause, whether a sensor issue or refrigerant loss, must be diagnosed and corrected before the unit will operate normally.
Can I fix E443 on my LG air conditioner myself?
Initial checks such as inspecting the high pressure sensor connector for looseness or visible damage are within reach for a knowledgeable DIYer. However, if the cause is a refrigerant leak or low refrigerant charge, handling and recharging refrigerant requires EPA certification and specialized equipment. Most homeowners will need to call a licensed HVAC technician to complete the repair safely and legally.
How much does it cost to repair a LG air conditioner with error E443?
Repair costs vary depending on the root cause. Replacing a faulty sensor or repairing a connector may cost in the range of $75 to $200 including labor. If the unit has a refrigerant leak, costs typically range from $200 to $600 or more, depending on the leak location, the amount of refrigerant required, and local labor rates. A compressor damaged by running in a low-pressure condition can cost $800 to $1,500 or higher to replace.

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