Digital Proctor Silex coffee maker shows E4 and shuts off shortly after starting.

Safety first: Unplug the unit and let it cool fully before any disassembly.

• Clean exterior vents: If your model has bottom or side vents, ensure they are not blocked by debris, dust, or being pushed tightly against a wall.
• Descale the system: Fill the reservoir with a 1:1 mix of white vinegar and water. Run a brew cycle until halfway, then pause for 20–30 minutes to let the solution soak. Resume the cycle, then run 2–3 full cycles of clean water to flush.
• Inspect sensor placement: Remove the bottom cover and locate the NTC sensor clipped to the heater or warming plate. Make sure it is firmly attached and not hanging loose, which can cause false high readings.
• Check wiring: Inspect the sensor wires for damage or melted insulation. Reseat the connector on the control board.
• Next steps: If E4 persists after descaling and wiring checks, the sensor or control board is likely defective. Replacement of the NTC sensor may resolve the issue; if not, the main control PCB may need replacement or the unit replaced.