mypros+
Error code reference

Samsung Air Conditioner Error Code P516

Outdoor unit discharge temperature 1 protection control.

Samsung codesSamsung air conditioner codes

Outdoor unit discharge temperature 1 protection control.

MyPros+ Max

Get the full diagnostic procedure for P516.

  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
Get the full procedure

$29/month · Cancel anytime · Or $9.95 3-day pass

What P516 means on a Samsung air conditioner

Error code P516 on a Samsung air conditioner indicates that the outdoor unit discharge temperature has exceeded its safe operating threshold, triggering a protection control response. The discharge temperature refers to the temperature of the refrigerant gas as it exits the compressor, before entering the condenser coil. This is one of the most thermally stressed points in the refrigeration circuit, and monitoring it is critical to protecting the compressor from heat-related damage. When the sensor detects a temperature beyond the acceptable limit, the system enters protection mode and may reduce capacity or shut down the compressor entirely.

High discharge temperatures typically point to problems with refrigerant charge levels, airflow through the outdoor unit, or compressor efficiency. An undercharged system causes the compressor to work harder with less refrigerant mass to cool internal components, driving discharge temperatures upward. Blocked condenser coils or a failed outdoor fan motor can also prevent adequate heat rejection, causing temperatures to climb. In some cases, a faulty discharge temperature sensor itself can generate a false P516 reading even when actual temperatures are within range.

Because P516 places the unit in a protective control state, normal cooling or heating operation will be limited or suspended until the underlying condition is resolved. Technicians should check refrigerant pressure readings, inspect the outdoor coil for debris or damage, verify outdoor fan operation, and test the discharge temperature sensor for correct resistance values before recharging or replacing components.

Source: manufacturer service documentation.

Common causes of P516

  1. 01

    Low refrigerant charge

    Part replacement

    An undercharged system forces the compressor to operate with insufficient refrigerant, causing discharge temperatures to spike. This is identified by checking system pressures with a manifold gauge set.

  2. 02

    Blocked or dirty outdoor condenser coil

    Wiring / connection

    Debris, dirt, or vegetation restricting airflow through the condenser coil prevents adequate heat rejection and causes discharge temperatures to rise. Inspect the coil fins for blockage and clean as needed.

  3. 03

    Outdoor fan motor failure or reduced speed

    Part replacement

    If the outdoor fan is not spinning at the correct speed or has stopped entirely, heat cannot be expelled from the condenser coil, leading to elevated discharge temperatures. Check fan rotation and motor amperage draw.

  4. 04

    Faulty discharge temperature sensor

    Part replacement

    A defective or out-of-calibration discharge temperature sensor can send incorrect high-temperature readings to the control board, triggering P516 even when actual refrigerant temperatures are normal. Test the sensor resistance against the expected specification curve.

  5. 05

    Compressor inefficiency or mechanical fault

    Part replacement

    A compressor with worn valves or internal mechanical issues may not move refrigerant efficiently, generating excessive heat at the discharge port. This is typically confirmed after ruling out refrigerant and airflow issues.

See the test procedure for each cause

Frequently asked questions about P516

What does P516 mean on a Samsung air conditioner?
P516 means the outdoor unit discharge temperature has exceeded its safe operating limit, activating a protection control response. The discharge temperature is measured at the point where refrigerant exits the compressor. The system enters protection mode to prevent compressor damage. A technician needs to identify whether the cause is low refrigerant, poor airflow, a failed fan, or a faulty sensor.
Can I fix P516 on my Samsung air conditioner myself?
Some causes, like clearing debris from the outdoor condenser coil, can be handled without professional help. However, diagnosing refrigerant charge issues, testing the discharge temperature sensor, or evaluating the compressor requires specialized tools and EPA certification for refrigerant handling. Most homeowners should contact a certified HVAC technician for this error.
Is it safe to keep running my Samsung air conditioner with a P516 error?
No, you should not attempt to force the unit to run while P516 is active. The protection control exists to prevent the compressor from sustaining heat-related damage. Continuing to operate the system with an unresolved discharge temperature problem can lead to compressor failure, which is significantly more costly to repair than the underlying cause of P516.
Will resetting my Samsung air conditioner clear the P516 error?
A power reset may temporarily clear the error code and allow the unit to restart, but if the underlying problem is not resolved, P516 will return once the discharge temperature exceeds the protection threshold again. Repeated resets without addressing the root cause increase the risk of permanent compressor damage. The error should be properly diagnosed before relying on a reset.
How much does it cost to repair a Samsung air conditioner showing P516?
Repair costs vary widely depending on the cause. Cleaning the condenser coil is typically inexpensive, ranging from around $75 to $200 for a service call. Refrigerant recharge can range from $150 to $400 or more depending on refrigerant type and the amount needed. Replacing a discharge temperature sensor generally falls in the $100 to $300 range including labor, while compressor replacement is significantly more expensive, often $800 to $2,000 or higher.

Related Samsung air conditioner codes

All Samsung air conditioner codes
View all 572 Samsung air conditioner codes

78,000+ service manuals · 160,000+ error codes · 55+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass