Display shows E2 and the coffee maker will not heat or brew.

Safety first: Unplug the coffee maker and allow it to cool completely before any inspection. The warming plate and internal heater can remain hot for several minutes after use.

• Power reset: Unplug the unit for at least 5 minutes to allow the control board to fully discharge. Plug it back in and check if E2 clears.
• Check for visible damage: Turn the unit over (unplugged) and inspect the underside around the warming plate area for signs of overheating, melted plastic, or burnt smell. Do not operate the unit if you see burn marks.
• Inspect wiring (advanced): If you are comfortable removing the bottom cover, carefully remove the screws and lift the base. Locate the small thermistor clipped to the warming plate or heater tube. Check that its wires are intact and the connector to the control board is firmly seated.
• Clean dust and residue: Use a dry brush or compressed air to remove dust from the control board and sensor area. Do not spray liquids inside.
• Replace faulty sensor: If the thermistor is cracked, burnt, or its leads are broken, it must be replaced with an Insignia-compatible temperature sensor. Reassemble the base securely before testing.

If E2 remains after sensor replacement, the main control board is likely defective and should be replaced by a professional.