mypros+
Error code reference

Samsung Air Conditioner Error Code E185

Power input error into indoor unit communication line

Samsung codesSamsung air conditioner codes

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

First step from the service manual

Check for disconnected line after turning off main power; reconfirm indoor unit comm line connection.

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

MyPros+ Max

Get the full diagnostic procedure for E185.

  • 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 E185 means on a Samsung air conditioner

Error code E185 on a Samsung air conditioner signals a power input error on the indoor unit communication line, specifically indicating that 220V AC voltage has been detected at the communication terminal block F1/F2. This terminal block is designed to carry low-voltage communication signals between the indoor and outdoor units, not line voltage. When 220V is applied to these terminals, the control board immediately registers a fault to protect the communication circuitry from damage.

The F1/F2 communication terminals operate as a signal pathway, not a power supply line. Miswiring during installation or servicing is the most common cause, where line voltage conductors are accidentally connected to communication terminals instead of the correct power input terminals. This can happen when wiring is pulled through conduit and leads are swapped, or when a technician unfamiliar with the unit's wiring diagram makes an incorrect connection. In some cases, damaged wiring insulation can allow a 220V conductor to contact the communication line downstream of the terminal block.

Before inspecting wiring, always shut off main power to the unit at the breaker or disconnect. With power off, verify that the conductors landed on F1/F2 are the low-voltage communication wires and not line voltage conductors. Compare the actual wiring against the unit's wiring diagram, which is typically located on the inside of the service panel. Correct any miswiring, re-secure connections, and restore power to confirm whether the fault clears.

Source: manufacturer service documentation.

Common causes of E185

  1. 01

    Miswired installation or service wiring

    Wiring / connection

    A 220V line voltage conductor was connected to the F1/F2 communication terminal block instead of the correct power terminals. This is the most common cause and is typically identified by comparing the installed wiring against the unit's wiring diagram.

  2. 02

    Swapped conductors in conduit or junction box

    Wiring / connection

    When multiple wires are routed through the same conduit, conductors can be pulled through and landed on incorrect terminals. Tracing each wire from the terminal block back to its origin will confirm whether a swap occurred.

  3. 03

    Damaged wire insulation causing contact with communication line

    Part replacement

    A 220V conductor with compromised insulation can make contact with the F1/F2 communication wiring downstream of the terminal block. Inspect all wiring for visible abrasion, pinching, or heat damage along the entire run.

  4. 04

    Failed or damaged communication terminal block

    Part replacement

    If the terminal block itself is cracked or carbonized from a prior voltage surge, it may need replacement even after the wiring error is corrected. Inspect the F1/F2 terminal block for burn marks or physical damage.

  5. 05

    Incorrect wiring after indoor control board replacement

    Wiring / connection

    If the indoor unit control board was recently replaced, the new board's communication terminals may have been wired incorrectly during reinstallation. Reconfirm all terminal connections against the wiring diagram after any board service.

See the test procedure for each cause

Frequently asked questions about E185

What does E185 mean on a Samsung air conditioner?
E185 indicates that 220V AC voltage has been detected on the indoor unit's F1/F2 communication terminal block, which is designed only for low-voltage communication signals. This is a wiring fault that prevents the unit from operating safely. The error is triggered to protect the communication circuitry from damage caused by the incorrect voltage. The root cause is almost always miswiring at the terminal block or along the communication line.
Can I fix the E185 error myself?
Resolving E185 requires identifying and correcting a high-voltage wiring error, which involves working near or with 220V conductors. Always shut off main power at the breaker before inspecting any wiring. If you are comfortable reading wiring diagrams and verifying conductor terminations, you may be able to identify the miswiring yourself, but the actual correction should be performed by a licensed HVAC or electrical technician given the shock hazard involved.
Is the E185 error on a Samsung air conditioner dangerous?
Yes, this error represents a serious electrical safety concern. Line voltage present on communication terminals can damage the indoor control board, create a fire risk, and pose a shock hazard to anyone handling the wiring. Do not attempt to operate the unit while this fault is active. Shut off power at the main breaker and have the wiring inspected before resuming use.
Will resetting the unit clear the E185 error?
Resetting the unit will not clear E185 if the underlying wiring fault has not been corrected. The error will return immediately upon restart because the 220V voltage will still be present on the F1/F2 terminals. The fault must be resolved by correcting the miswiring and confirming proper connections before the error code will clear.
How much does it cost to repair an E185 error on a Samsung air conditioner?
If the fix involves only correcting a wiring error with no damaged components, the cost is primarily a service call fee, typically in the range of $75 to $150 depending on location. If the communication terminal block or indoor control board was damaged by the voltage exposure, parts and labor can bring the total to between $200 and $600 or more. Getting a diagnostic assessment from a technician before authorizing parts replacement is advisable.

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