Dishwasher displays C4 and stops; may fill briefly then drain, or may not fill at all.

Safety: Turn off power and close the dishwasher water supply valve (usually under the sink) before servicing.

• Check household water supply: Confirm other fixtures at the sink have normal pressure. Ensure the shutoff valve feeding the dishwasher is fully open.
• Inspect the fill hose: Pull the dishwasher slightly out from the cabinet (after removing mounting screws) and check that the inlet hose is not kinked or crushed.
• Clean the inlet valve screen: Turn off water, disconnect the inlet hose from the valve at the dishwasher, and inspect the small screen inside the valve fitting. Remove sediment with a small brush and rinse.
• Test fill operation: Reconnect the hose, restore water and power, and start a cycle. Listen for the valve opening and check if water enters the tub within 30–60 seconds.
• Replace the inlet valve if needed: If you hear a hum but no water flows (and supply is confirmed), or the valve is silent and not energizing, the water inlet valve is likely faulty and should be replaced with a compatible Monogram part.

Persistent C4 errors after verifying supply and cleaning the screen indicate a failing inlet valve or control board issue that may require professional diagnosis.