Digital Bissell carpet cleaner shows E8 and heater function is disabled; water remains cold.

Safety: Unplug the unit and allow it to cool completely before accessing the heater. Water and electricity are a dangerous combination.

• 1. Verify model has a heater: Not all Bissell carpet cleaners include a built-in heater. Confirm your model's features in the user manual.
• 2. Inspect external heater connections: On models with an external in-line heater, check the wiring harness and connectors for looseness or corrosion. Reseat all plugs.
• 3. Descale the heater path: Mineral buildup can cause overheating and sensor errors. Run a tank of warm water mixed with white vinegar (per Bissell guidelines) through the system, then flush with plain water.
• 4. Internal testing (advanced): With the housing removed, locate the heater block. Use a multimeter (if qualified) to test continuity across the heater element and thermal fuse. An open circuit indicates a failed component.
• 5. Replace heater assembly: If the heater or thermal fuse is open, replace the complete heater assembly. If the heater tests good but E8 persists, the temperature sensor (NTC) or main control board may be defective.