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Error code reference

LG Heat Pump Error Code E334

Low pressure sensor breakaway.

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What the E334 error code actually means

Your LG heat pump is displaying this error because it has lost communication with the sensor that monitors refrigerant pressure on the intake side of the system. This could mean the sensor wire came loose, the sensor itself failed, or there is a wiring problem between the sensor and the control board. The system has shut itself down as a safety precaution to protect the compressor from potential damage.

Diagnostic procedure

The full E334 procedure

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1
Confirm the fault
Power cycle the unit: switch off the breaker for 60 seconds, then restore power. If the code returns, the fault is persistent and the procedure below isolates the cause.
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Most common causes of E334

Ranked by how often they cause this code
  1. 1Loose or disconnected sensor connector
  2. 2Damaged sensor wiring harness
  3. 3Corroded or oxidized connector pins
  4. 4Failed low pressure sensor or transducer
  5. 5Control board fault

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Questions people ask about E334

What does E334 mean on a LG heat_pump?
E334 on an LG heat pump indicates a low pressure sensor breakaway condition. The system has detected that the low pressure sensor signal is missing or outside the valid operating range, suggesting the sensor has disconnected, its wiring is damaged, or the sensor itself has failed. The unit shuts down to protect the compressor until the fault is resolved.
Is it safe to keep running my LG heat pump with error code E334?
No. The E334 error causes the system to shut down as a protective measure, and you should not attempt to bypass this shutdown. Operating the heat pump without a functioning low pressure sensor removes a key safeguard for the compressor, which could result in serious and costly compressor damage if refrigerant pressure drops too low during operation.
Will resetting my LG heat pump clear the E334 error code?
A reset may temporarily clear the E334 code, but if the underlying cause such as a loose connector, damaged wire, or failed sensor is still present, the error will return. It is important to diagnose and correct the root cause before relying on a reset. Repeated resets without addressing the fault will not resolve the issue and could allow compressor damage to occur.
Can I fix E334 on my LG heat pump myself?
A knowledgeable DIYer can safely inspect the low pressure sensor wiring harness and connectors for obvious disconnections, damage, or corrosion. However, if the issue requires working with refrigerant lines or replacing components near the refrigerant circuit, a licensed HVAC technician should perform the repair. Refrigerant handling is regulated and requires proper certification and equipment.
How much does it cost to repair error code E334 on an LG heat pump?
Repair costs depend on what is causing the fault. If the fix is simply reseating a loose connector, the cost may be limited to a service call fee, typically in the range of $75 to $150. Replacing a damaged wiring harness or a failed low pressure sensor generally runs between $150 and $400 including parts and labor. Control board replacement, if needed, can push costs significantly higher.

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