Machine shows E03 and stops heating; no steam and coffee is lukewarm or cold.

Safety first: Unplug the Dualit coffee maker and allow at least 30 minutes for full cooling. Internal components can remain very hot.

Initial user actions:

• Power reset: Disconnect from mains for 10 minutes, then reconnect and test. If E03 returns immediately, proceed to inspection.
• Descale: If the machine will still run a cycle, perform a full descaling using a Dualit-approved descaler. Heavy scale can cause overheating and trigger protection.

Internal inspection (advanced):

• Access boiler/thermoblock: Remove the outer cover to expose the heating assembly.
• Locate thermal cut-outs: Identify the thermal fuse and any manual reset thermostats attached to the boiler or thermoblock.
• Check manual reset thermostat: Some models have a small button on the thermostat. Press gently to reset if it has tripped.
• Test thermal fuse: With a multimeter, check continuity across the thermal fuse. If open, it must be replaced with the exact temperature and rating specified by Dualit.
• Inspect for scale and leaks: Look for white scale deposits or signs of leakage around the boiler. Severe scale may require boiler replacement.
• Test heating element: Measure resistance across the heater terminals. An open circuit indicates a failed element.

Important: Never bypass a thermal fuse or thermostat. If you are not comfortable with electrical testing, contact a qualified technician.