E8 error appears and the unit will not spray detergent, though water may still spray.

Safety first: Unplug the Philips carpet cleaner and remove the detergent cartridge or tank.

• Check detergent level: Ensure the Philips detergent cartridge or tank is filled and correctly seated. Some models will show E8 if the cartridge is missing or not latched.
• Clean injector and lines: Locate the detergent injection point where detergent mixes with water. Remove and soak the injector in warm water to dissolve dried detergent. Flush the detergent hose with warm water using a syringe or small pump.
• Inspect detergent pump/valve: Access the detergent pump or solenoid valve inside the unit. Check for clogged inlet screens and ensure the electrical connector is firmly attached.
• Prime the system: Reinstall the cartridge, then run the unit while holding the detergent trigger for 30–60 seconds to purge air. Observe if detergent begins to flow.
• Sensor and component replacement: If the detergent level sensor (often a float or optical sensor in the cartridge bay) is stuck or disconnected, clean and reseat it. Replace the detergent pump/valve or sensor if they fail continuity or do not actuate when powered.