Display shows E3 and brewing stops shortly after starting, often with no water flowing through the filter basket.

Safety first: Unplug the coffee maker and let it cool for at least 30 minutes. The internal heater and warming plate may be extremely hot.

• Check water level: Ensure the reservoir is filled above the minimum line. Running the unit dry can trigger E3.
• Descale the machine: Mineral buildup can cause localized overheating. Fill the reservoir with a 1:1 mixture of white vinegar and water. Run a brew cycle without coffee, then stop halfway and let it sit for 20 minutes. Resume and complete the cycle, then run 2–3 full cycles with clean water to rinse.
• Inspect for blockages: Remove the filter basket and check the outlet hole for coffee grounds or paper filter fragments. Clean with warm water and a soft brush.
• Reset thermal protection (if accessible): Some Insignia models have a manual-reset thermostat on the heater. With the base removed (unplugged), look for a small round thermostat with a red or black reset button. Press gently to reset if tripped.
• Test again: Reassemble, plug in, and run a water-only cycle. If E3 returns quickly, the thermostat, thermal fuse, or control board may be defective.

Do not bypass or short any safety thermostats or fuses. If the unit repeatedly overheats, have it inspected by a technician.