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Error code reference

Samsung Air Conditioner Error Code Ch

Compressor preheating in progress

Samsung codesSamsung air conditioner codes

Compressor preheating in progress - CCH (crank case heater) is heating the compressor for up to 2.5 hours before operation is permitted.

First step from the service manual

Wait for preheating to complete (up to 2.5 hours); for first-time installation, power should be applied 6 hours before operation.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What Ch means on a Samsung air conditioner

The Ch code on a Samsung air conditioner indicates that the crank case heater (CCH) is actively preheating the compressor before allowing the system to begin normal operation. The CCH is a resistive heating element mounted at the base of the compressor that warms the crankcase oil to prevent refrigerant from migrating into and mixing with the compressor lubricant during periods of inactivity. When refrigerant dissolves into cold compressor oil, it can cause oil foaming and inadequate lubrication on startup, which leads to premature compressor wear or failure. The Ch code is a protective hold, not a fault condition.

This preheating sequence can run for up to 2.5 hours under normal circumstances. For first-time installations or situations where power has been disconnected for an extended period, Samsung specifies that power should be applied at least 6 hours before the unit is operated to ensure the compressor oil is fully conditioned. During this window, the indoor unit may display Ch continuously and refuse to start a cooling or heating cycle. This behavior is by design and protects the compressor from damage caused by liquid refrigerant slugging.

The Ch code is most commonly seen after power outages, seasonal startup after the unit has been off for months, or following installation. Ambient temperature also plays a role, as colder outdoor conditions cause more refrigerant to migrate into the oil and require a longer or more thorough preheat cycle before oil viscosity and refrigerant concentration return to safe operating levels.

Source: manufacturer service documentation.

Common causes of Ch

  1. 01

    Power restored after outage or disconnection

    Wiring / connection

    When power is interrupted and then restored, the compressor crank case heater must reheat the compressor oil from scratch. This is the most frequent trigger for the Ch code and requires no repair, only waiting.

  2. 02

    Seasonal startup after extended shutdown

    Wiring / connection

    If the unit has been powered off for weeks or months, refrigerant migrates into the compressor oil during that idle period. The CCH needs additional time to drive off that refrigerant before safe operation is possible.

  3. 03

    First-time installation or reinstallation

    Wiring / connection

    A newly installed or recently reinstalled unit has never had power applied to the CCH, so the compressor oil starts at ambient temperature. Samsung specifies applying power 6 hours before first operation in this scenario.

  4. 04

    Cold ambient outdoor temperatures

    Wiring / connection

    Very low outdoor temperatures accelerate refrigerant migration into compressor oil and may extend the time the CCH needs to adequately condition the oil. The Ch code will display longer in cold climates during winter startups.

  5. 05

    Faulty or failed crank case heater

    Part replacement

    If the CCH element has failed, the compressor oil never reaches the required temperature and the Ch code may persist beyond 2.5 hours without clearing. This would require testing and replacing the heater element.

See the test procedure for each cause

Frequently asked questions about Ch

What does Ch mean on a Samsung air conditioner?
Ch stands for compressor preheating and indicates the crank case heater (CCH) is warming the compressor oil before the system is allowed to run. This is a protective function that prevents compressor damage from refrigerant that has mixed with the lubricating oil during a period of inactivity. The code is not a fault and will clear on its own once preheating is complete, which takes up to 2.5 hours.
How do I fix the Ch code on my Samsung air conditioner?
In most cases, no repair is needed. Simply leave the unit powered on and allow the preheating cycle to finish, which takes up to 2.5 hours. For a brand new installation or a unit that has been without power for an extended time, apply power and wait at least 6 hours before attempting to operate the system. If the Ch code persists well beyond 2.5 hours, the crank case heater element may have failed and should be inspected by a technician.
Is it safe to leave my Samsung air conditioner showing the Ch code?
Yes, it is completely safe to leave the unit powered on while the Ch code is displayed. The crank case heater is simply running its normal warmup cycle and the system is functioning as intended. Do not attempt to force the unit to start or cut and restore power repeatedly, as interrupting the preheat cycle can extend the total wait time.
Will resetting my Samsung air conditioner clear the Ch code?
Resetting or cycling power will not clear the Ch code faster and will actually restart the preheating timer from the beginning. The code will only clear once the compressor oil has been heated to the required temperature over the full preheat period. Leave the unit powered on and allow the cycle to complete without interruption.
How much does it cost to repair a Samsung air conditioner stuck on Ch?
If the Ch code clears on its own after the preheat period, there is no repair cost involved. If the code persists beyond 2.5 hours due to a failed crank case heater element, a service call including diagnosis and parts typically ranges from around 150 to 400 dollars depending on the unit model, labor rates in your area, and parts availability. A technician should confirm the heater element has actually failed before any parts are ordered.

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