E17 error appears and the unit will not heat water or enable a 'warm clean' mode (on heated models).

Safety first: Unplug the Philips carpet cleaner. Water heaters operate at mains voltage and can be hazardous.

• Access heater assembly: Remove covers to locate the inline water heater block and its wiring.
• Check wiring and connectors: Ensure all heater terminals are firmly connected and show no signs of overheating.
• Test heater element: With a multimeter, measure resistance across the heater terminals. An open circuit indicates a failed heater or internal thermal fuse.
• Check temperature sensor: Measure the resistance of the NTC sensor attached to the heater. Compare with service data if available; a reading of 0 Ω or infinite Ω usually indicates failure.
• Replace faulty parts: Replace the heater assembly if open or shorted. Replace the NTC sensor if it reads out of range. Reassemble and test.

If you are not comfortable working around mains-voltage heating elements, contact a professional technician.