Display shows E3 and brewing stops; sometimes accompanied by very hot steam or no heating at all on Swan coffee maker.

Safety first: Immediately unplug the coffee maker. Allow it to cool for at least 45 minutes before any inspection.

User-level checks:

• Check water level: Ensure the water reservoir is filled above the minimum line and properly seated. Many Swan models will overheat if run dry and then trigger E3.
• Descale the machine: Mineral buildup can restrict water flow and cause overheating. Run a full descaling cycle following the Swan manual, using descaling solution. Repeat if the machine is heavily scaled.
• Clean the filter basket: A clogged paper or permanent filter can cause back-pressure and overheating. Remove and thoroughly rinse the filter basket and drip outlet.

Advanced checks (for experienced users):

• Remove the base cover to access the thermal fuse and bi-metal thermostat mounted on the heating plate or boiler.
• Visually inspect for discoloration or burn marks. Test continuity of the thermal fuse with a multimeter; an open fuse must be replaced with the same temperature and current rating.
• Check the thermostat for proper operation (closed at room temperature for most coffee makers). Replace if stuck open or shows signs of arcing.

Important: Never bypass a thermal fuse or thermostat. If you are unsure, contact a qualified appliance technician.