Capresso coffee maker displays E4 and will not brew or heat.

Safety first: Unplug the coffee maker and allow it to cool for at least 30–45 minutes.

Steps:

• Check water level: Ensure the water reservoir is filled above the minimum mark and properly seated.
• Reset the unit: After cooling, plug the machine back in and attempt a brew cycle. Some models clear E4 after a full cool-down and power reset.
• Descale the heating system: If the machine has been used with hard water and rarely descaled, run a full descaling cycle to remove mineral buildup from the thermoblock or boiler. Follow Capresso’s descaling instructions for your model.
• Inspect for signs of overheating: If you notice a burnt smell, discoloration, or melted plastic around the base, discontinue use. The thermal cutoff or thermostat may have opened permanently.
• Professional service: If E4 returns immediately after reset and descaling, the thermal cutoff, thermostat, or control board likely needs replacement. This involves accessing the heater assembly and should be done by a technician.