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Samsung Air Conditioner Error Code E505

Error due to self diagnosis of high pressure sensor.

Samsung codesSamsung air conditioner codes

Error due to self diagnosis of high pressure sensor.

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What E505 means on a Samsung air conditioner

The Samsung air conditioner error code E505 indicates a fault detected during the unit's self-diagnosis routine for the high pressure sensor. The high pressure sensor monitors refrigerant pressure on the discharge side of the compressor circuit. When the system's internal diagnostics detect that the sensor's output signal is outside of expected parameters, or that the sensor has failed to respond correctly, the E505 code is triggered and the unit typically shuts down to prevent compressor or system damage.

The high pressure sensor is a critical safety component. It protects the system from operating under excessively high refrigerant pressures, which can cause compressor failure, refrigerant line damage, or other serious mechanical issues. The self-diagnosis function checks the sensor's signal continuously during operation, and if the reading is implausible, absent, or out of range, the unit flags the fault rather than continuing to run blind.

Common causes of E505 include a failed or failing high pressure sensor, damaged wiring or connector pins on the sensor circuit, an actual high pressure condition in the refrigerant circuit (such as from overcharge or restricted airflow through the condenser), or a fault on the control board that processes the sensor signal. Distinguishing between a genuine high pressure condition and a sensor/wiring fault is a key early diagnostic step, as the correct repair path differs significantly between these two scenarios.

Source: manufacturer service documentation.

Common causes of E505

  1. 01

    Failed high pressure sensor

    Part replacement

    The sensor itself may have failed internally, producing a signal that falls outside the range the control board expects. This can be confirmed by checking the sensor's output signal or resistance against specification.

  2. 02

    Wiring or connector fault on sensor circuit

    Wiring / connection

    Damaged wires, corroded terminals, or a loose connector between the high pressure sensor and the control board can interrupt or distort the signal. Inspect the harness and connector pins for damage, corrosion, or backed-out terminals.

  3. 03

    Actual high refrigerant pressure condition

    Wiring / connection

    If the condenser coil is dirty, airflow is blocked, or the refrigerant circuit is overcharged, real high pressure conditions can trigger the sensor fault. Check condenser coil cleanliness and airflow before assuming the sensor is defective.

  4. 04

    Refrigerant system overcharge

    Wiring / connection

    Excess refrigerant in the system raises discharge-side pressure beyond normal operating limits, causing the sensor to report a fault condition. This requires a certified technician to measure and adjust refrigerant charge.

  5. 05

    Control board fault

    Part replacement

    If the control board's sensor input circuit has failed, it may misread or fail to read the high pressure sensor signal even when the sensor itself is functioning correctly. This is typically diagnosed after ruling out the sensor and wiring.

See the test procedure for each cause

Frequently asked questions about E505

What does E505 mean on a Samsung air conditioner?
E505 on a Samsung air conditioner indicates an error detected during the unit's self-diagnosis of the high pressure sensor. The system has flagged that the high pressure sensor's signal is absent, implausible, or out of the expected range. The unit typically shuts down when this code appears to protect the compressor and refrigerant circuit from potential damage.
Can I fix E505 on my Samsung air conditioner myself?
Some basic checks are safe for a homeowner, such as cleaning a dirty condenser coil or ensuring the outdoor unit has adequate airflow clearance around it. However, diagnosing and replacing the high pressure sensor, testing refrigerant pressures, or inspecting internal wiring requires technical knowledge and proper equipment. Any work involving refrigerant must be performed by a certified technician.
Will resetting the unit clear the E505 error code?
A power reset may temporarily clear the E505 code and allow the unit to restart, but if the underlying cause is still present, the error will return. A reset is useful as an initial step to see if the fault was a transient glitch, but a persistent E505 code requires proper diagnosis of the sensor, wiring, and refrigerant circuit.
Is it safe to run my air conditioner with an E505 error?
It is not recommended to continue operating the unit while E505 is active. The high pressure sensor is a safety component, and if it has failed or is reporting a genuine high pressure condition, running the compressor without proper protection risks compressor damage or refrigerant line failure. Leave the unit off until the fault has been diagnosed and repaired.
How much does it cost to repair an E505 error on a Samsung air conditioner?
Repair costs depend on the root cause. Replacing a high pressure sensor typically falls in the range of $100 to $300 including parts and labor. If the issue is a refrigerant overcharge or a dirty coil, service costs may be lower, generally in the $75 to $200 range. A control board replacement would be at the higher end of the cost spectrum, potentially $300 to $600 or more depending on the unit model.

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