What Does Error Code AC Mean on a Samsung Washing Machine?

Samsung Updated 28 March 2026
Quick Fix

Unplug the washing machine from the wall socket, wait 5 minutes, then plug it back in and restart a wash cycle — this clears the majority of AC errors caused by temporary communication glitches (takes about 5 minutes).

Fault description

Error code AC points to a breakdown in communication between two key electronic components inside your Samsung washing machine: the main control board (also called the PCB) and the motor inverter board. These two boards constantly exchange signals to coordinate motor speed and drum movement. When that signal is interrupted or lost, the machine stops and displays AC to protect itself from running incorrectly.

When this error appears, the wash cycle will halt and the machine will typically become unresponsive until the fault is cleared. You may notice the display freezing, the drum stopping mid-cycle, or the machine refusing to start at all. In many cases the fault is temporary — caused by a power fluctuation or a brief signal dropout — and a simple reset is all that is needed.

However, if the error returns repeatedly after resetting, there is likely an underlying electrical or hardware problem that needs closer attention. The steps below will help you work through the most common causes in order, from the simplest fix to the more involved ones.

Causes

  • Temporary communication glitch — A brief power fluctuation or software hiccup can cause the two boards to lose sync momentarily. This is the most common reason for a first-time AC error and usually clears after a full power reset.
  • Loose or damaged wiring harness — The ribbon cable or wiring loom connecting the main control board to the motor inverter board can work loose over time due to vibration. A partially disconnected or corroded connector will cause intermittent or persistent communication failures.
  • Faulty motor inverter board — The inverter board controls the motor's speed and direction. If it develops an internal fault — due to a power surge, component failure, or age — it may stop responding to signals from the main board, triggering the AC error.
  • Defective main control board (PCB) — Less commonly, the main control board itself is the source of the problem. If it cannot send or receive communication signals correctly, the AC error will appear regardless of the condition of the inverter board.
  • Power supply instability — Voltage fluctuations from the mains supply or a faulty power outlet can disrupt the electronics inside the machine. If your home has experienced recent power cuts or surges, this may have triggered or contributed to the fault.

Step-by-Step Fix

  1. 1

    Perform a full power reset

    Switch the washing machine off using the power button, then unplug it from the wall socket. Leave it unplugged for at least 5 minutes — this allows the capacitors on the control boards to fully discharge and clears any temporary error states. Plug it back in, select a short wash cycle, and observe whether the AC error returns.

  2. 2

    Check the power outlet and supply

    Plug another appliance into the same socket to confirm it is working correctly. Avoid using an extension lead or multi-socket adaptor with your washing machine — these can cause voltage drops that affect sensitive electronics. If the socket seems faulty, try a different outlet on a separate circuit.

  3. 3

    Inspect the wiring harness connections

    Before doing this, unplug the machine from the mains. Remove the back panel of the washing machine (usually held by a few Phillips-head screws) to access the internal boards. Locate the wiring loom running between the main control board and the motor inverter board, and press each connector firmly into place. Look for any signs of burning, corrosion, or broken wires. Refit the panel and test the machine.

  4. 4

    Check for visible damage on both boards

    With the back panel removed and the machine unplugged, visually inspect both the main control board and the motor inverter board. Look for burnt components, swollen capacitors, scorch marks, or cracked solder joints. Any visible damage is a strong indicator that the affected board needs replacing rather than repairing.

  5. 5

    Test or replace the motor inverter board

    If the wiring is intact and there is no visible damage, the inverter board is the more likely faulty component of the two. Source a compatible replacement board using your machine's full model number (found on the label inside the door rim). Swap the board, reconnect all wiring carefully, and run a test cycle to confirm the error is resolved.

  6. 6

    Test or replace the main control board

    If replacing the inverter board does not clear the AC error, the main control board is the next component to address. Again, match the replacement part to your exact model number. If you are not confident working with electronic components, this is the point at which calling a service technician is the safer and more cost-effective option.

Affected models

When to call a service technician

If the AC error returns immediately after every reset, or if you have inspected the wiring and found no obvious loose connections, it is likely that one of the control boards has failed internally. Board-level faults are difficult to diagnose without specialist test equipment, and incorrect installation of a replacement board can cause further damage to the machine.

You should also contact a service technician if you notice any burning smell, scorch marks on the boards or wiring, or if the machine trips your home's circuit breaker when switched on. These are signs of a more serious electrical fault that should not be investigated without professional knowledge and tools.

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Frequently Asked Questions

Will the AC error clear itself if I leave the machine for a while?

Sometimes, yes. If the error was caused by a temporary power fluctuation or communication dropout, unplugging the machine for 5-10 minutes and restarting it is often enough to clear it. However, if the error reappears on the next cycle or immediately after reset, there is an underlying fault that will not resolve on its own.

Can I still use my washing machine if it shows error code AC?

No — when the AC error is active, the machine will stop the cycle and will not operate normally. Attempting to force it to run could cause further damage to the control boards or motor. It is best to resolve the fault before using the machine again.

How do I know whether it is the inverter board or the main control board that has failed?

Without specialist diagnostic equipment it can be difficult to tell the two apart. As a general rule, start with the inverter board since it is the more commonly replaced component for the AC error. If replacing it does not fix the problem, the main control board is the next step. A service technician can test both boards with a multimeter to confirm which has failed before any parts are ordered.

Is error code AC the same as error code AC6 or 1AC on Samsung machines?

They are related but not identical. All three codes point to communication issues between the control board and the inverter board, but AC6 and 1AC are more specific sub-codes that appear on newer Samsung models. The diagnostic approach and likely causes are very similar across all three codes.

How much does it typically cost to fix error code AC on a Samsung washing machine?

If a power reset resolves the issue, there is no cost at all. If a board replacement is needed, the inverter board typically costs between £30 and £80 for the part, while the main control board can range from £60 to £150 depending on the model. Add labour costs if you use a service technician. It is worth comparing the repair cost against the age and value of the machine before committing to an expensive board replacement.