EdgeStar ice maker shows E4; unit may run briefly then shut down, or may not start the ice-making cycle at all.

Safety first: Unplug the unit and shut off the water supply before disconnecting any water lines.

• Verify water supply: Confirm the household shutoff valve feeding the EdgeStar ice maker is fully open. Check the supply hose for kinks or crushing behind the unit.
• Inspect the inlet filter screen: Disconnect the water line from the back of the ice maker. At the water inlet valve, look for a small mesh screen. Rinse it under running water to remove sediment.
• Check for adequate flow: Briefly open the supply line into a bucket to confirm strong water flow from the house plumbing (have towels ready).
• Test the valve (if equipped to do so): With power disconnected, remove the valve and check coil resistance with a multimeter. A reading of open circuit indicates a failed coil.
• Replace the water inlet valve: If the valve coil is open, the body is cracked, or E4 persists despite good supply, install a new EdgeStar water inlet valve assembly. Use new compression washers or gaskets as required and check for leaks after restoring water.