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Error code reference

Samsung Air Conditioner Error Code 185

Power input error into indoor unit communication line

Samsung codesSamsung air conditioner codes

Power input error into indoor unit communication line - 220V applied to F1/F2 communication terminal block.

First step from the service manual

Reconfirm the indoor unit communication line connection; check for power line input on F1/F2 terminals.

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

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What 185 means on a Samsung air conditioner

Error code 185 on a Samsung air conditioner indicates a power input error on the indoor unit communication line, specifically that 220V AC power has been detected on the F1/F2 communication terminal block. The F1 and F2 terminals are designated for low-voltage communication signals between the indoor and outdoor units, not for line voltage. When 220V is applied to these terminals, the system detects an incompatible electrical input and throws this fault to prevent damage to the communication circuitry and control boards.

This error is almost always the result of incorrect wiring during installation or after a service visit. The most common scenario involves the communication wires being connected to power terminals rather than the dedicated signal terminals, or line voltage wires being accidentally routed to the F1/F2 block. This can also occur if the terminal block labels are misread or if wiring from a previous installation was not properly removed before the new unit was connected.

The communication line between indoor and outdoor units carries low-level data signals, and exposure to 220V can permanently damage the indoor unit PCB, the outdoor unit control board, or both. Before attempting any further diagnostics or powering the unit back on, the wiring at the F1/F2 terminal block must be inspected and corrected. Confirm that only the designated communication conductors are connected to F1 and F2, and that no line voltage conductors are present at those terminals.

Source: manufacturer service documentation.

Common causes of 185

  1. 01

    Miswired communication terminals during installation

    Wiring / connection

    The most frequent cause is that 220V line voltage wires were connected to the F1/F2 communication terminal block instead of the correct power terminals. Inspect all wiring at the indoor unit terminal block and verify each conductor is connected to its correct terminal.

  2. 02

    Incorrect wiring after a service or maintenance visit

    Wiring / connection

    If the unit was recently serviced, wires may have been reconnected incorrectly after the work was completed. Check whether the wiring configuration changed after the most recent service call.

  3. 03

    Crossed wires in the inter-unit cable

    Wiring / connection

    The cable running between the indoor and outdoor units may have conductors that are swapped or incorrectly terminated at one or both ends, resulting in line voltage reaching the communication terminals. Trace the cable and verify terminations at both units.

  4. 04

    Damaged indoor unit PCB from sustained 220V exposure

    Part replacement

    If the unit was operated with 220V on the F1/F2 terminals for any period of time, the indoor unit control board may have been damaged by the overvoltage. If correcting the wiring does not clear the fault, the PCB will need to be tested and potentially replaced.

  5. 05

    Incorrect terminal block labeling or terminal confusion

    Wiring / connection

    Some installation scenarios involve terminal blocks where labels are worn, unclear, or non-standard, leading to the wrong terminals being used for communication wiring. Consult the wiring diagram affixed to the unit and verify each terminal assignment before powering on.

See the test procedure for each cause

Frequently asked questions about 185

What does 185 mean on a Samsung air conditioner?
Error code 185 means the system has detected 220V AC power being applied to the F1/F2 communication terminal block on the indoor unit. These terminals are intended for low-voltage communication signals between the indoor and outdoor units, not for line voltage. The unit shuts down to prevent damage to the control boards when this condition is detected. The root cause is almost always a wiring error.
Can I fix error code 185 myself?
If you are comfortable working with electrical wiring and can safely isolate power to the unit, you can inspect the F1/F2 terminal block to verify that no line voltage conductors are connected to it. However, because this error involves 220V wiring, it is strongly recommended that a qualified technician perform the inspection and correction. Attempting to adjust wiring while power is on poses a serious electrocution risk.
Is error code 185 dangerous?
Yes, this condition is potentially dangerous. Having 220V applied to communication terminals that are not rated for line voltage can cause electrical damage to the control boards and creates a risk of fire or electrical shock if the wiring is not corrected promptly. Power to the unit should be shut off at the breaker until the wiring is properly inspected and repaired.
Will resetting the unit clear error code 185?
Resetting the unit will not resolve error code 185 because the underlying cause is a physical wiring problem, not a temporary sensor or communication glitch. The 220V on the F1/F2 terminals must be corrected before the error will clear. Simply cycling power without fixing the wiring will result in the fault returning immediately and may cause further damage to the control boards.
How much does it cost to repair error code 185 on a Samsung air conditioner?
If the problem is only a wiring correction with no component damage, repair costs are typically limited to a service call fee, which can range from $75 to $150 depending on the technician and region. If the 220V exposure has damaged the indoor unit PCB or outdoor control board, parts and labor costs can range from $200 to $600 or more depending on the specific boards affected and local labor rates.

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