Knob on Detergent Injector is Closed – Open knob by turning clockwiseInadequate Detergent Supply – Check level of detergent in supply container. Be certain that the end of the pick up tube (with screen) is fully immersed and that the detergent strainer is not clogged.Pressure Washer Not in Low Pressure Mode – Downstream detergent injectors are designed for use in low pressure applications. Install low pressure spray tip nozzle or open dual lance wand.Detergent Screen or Hose Clogged – Clean screen or hose as needed. Recommend always starting with a clean detergent containerDetergent Injector Check Valve is Clogged – Clean check valve at detergent injector inletImproperly Mixed Detergent or Incorrect Dilution Ratio – Detergents are available in a variety of concentrations; some that require dilution. Improper concentrations or poorly mixed powdered detergents will result in negative cleaning effects.Rinsing with Hot Water – A final rinse with cold water is recommended to reduce water spotting