Display shows E1 and brewing will not start or stops immediately after pressing the brew button.

Safety first: Unplug the coffee maker before removing the reservoir or accessing any internal parts. Never work on the unit while it is connected to power.

• Reseat the water reservoir: Remove the reservoir completely, check for debris or coffee grounds on the bottom mating surface and the rear guide rails, then firmly reinstall it until it sits flush against the back of the machine.
• Check water level: Fill the reservoir at least halfway. Some Insignia models will show E1 if the float is below the minimum sensing point.
• Inspect the float: Look inside the reservoir for a small plastic float with an embedded magnet. Make sure it moves freely up and down. If it is stuck, rinse the reservoir with warm soapy water and move the float by hand to free it. Rinse thoroughly before use.
• Clean the sensor area: On the base where the reservoir sits, wipe the sensor area and contacts with a dry cloth. Do not use excessive water near the electrical contacts.
• Test again: Reinstall the reservoir, plug the unit back in, and try a brew cycle. If E1 persists, the internal reed switch or wiring may be faulty and the sensor assembly or main control board may need replacement.

If you are not comfortable opening the housing to access the sensor wiring, contact a qualified appliance technician.