Samsung Washer Error Code UC — Voltage Fluctuation Detected
What this means
The UC error code indicates the washer's control board has detected voltage fluctuations that could interfere with normal operation. Unlike 9C2 (which indicates sustained high voltage), UC typically appears when voltage is rapidly fluctuating — rising and dropping repeatedly. This is common in areas with unstable power grids, during storms, or when high-power equipment cycles on and off nearby.
Alternate codes: uC
Step-by-step fix
4 stepsWait and retry
The UC code often appears during temporary power fluctuations. Wait 10–15 minutes for the power to stabilize, then try starting the cycle again.
If a storm is in progress or the lights in your home are flickering, wait until conditions stabilize.
Unplug and reconnect
Unplug the washer for 2 minutes, then plug it back in. This resets the voltage monitoring circuit and clears the error if the fluctuation has passed.
If the code returns immediately, voltage is still unstable.
Avoid sharing the circuit
Make sure no other high-power appliances (space heaters, hair dryers, microwaves) are on the same circuit as the washer. These can cause voltage drops when they cycle on.
The washer should ideally be on a dedicated 20-amp circuit.
Check for loose outlet connections
A loose plug in the outlet or a worn outlet can cause intermittent voltage drops. Push the plug in firmly. If the outlet feels loose, have an electrician replace it.
If the plug falls out or doesn't stay snug in the outlet, the outlet contacts are worn.
When to call a professional
If the UC code appears frequently, call an electrician to test the circuit for loose connections or a failing breaker. Persistent voltage fluctuations can damage the control board over time.
Information compiled from manufacturer service manuals, official troubleshooting documentation, and appliance repair industry resources. This guide is for informational purposes only — always consult a qualified technician for complex repairs.
Learn more about our sourcesParts you may need
No parts needed for most cases
Part #N/A · N/A
This is typically a power supply issue, not a washer hardware problem
Links may earn us a commission at no extra cost to you. We only recommend parts relevant to this repair.