Dishwasher displays C3 and may stop with water still in the tub or repeatedly attempt to drain.

Safety: Disconnect power at the breaker before opening panels or accessing internal components.

• Inspect the tub bottom: Remove the lower rack and filters. Clean all debris from the sump area, including around any float or sensor housings.
• Check for stuck float: Some Monogram models use a float or float switch to detect overfill. Locate the float (usually near the front corner of the tub) and ensure it moves freely up and down. Clean any soap scum or food residue.
• Verify drain pump operation: Access the bottom of the dishwasher and inspect the drain pump for obstructions. Spin the impeller gently with a finger (power off) to ensure it is not jammed.
• Look for leaks or standing water in base pan: If the base pan under the tub has water, the safety system may keep the pump running. Dry the pan completely and identify any leak source before restarting.
• Reset the unit: After cleaning and drying, restore power and run a short cycle to see if the C3 code clears.

If the error returns and no obstructions or leaks are found, the water level sensor or control board may be defective and should be diagnosed with a meter by a technician.