If the chemical injector on your pressure washer is not working, it could be due to a number of factors, including
A clogged injector The injector can become clogged with dirt, debris, or chemical residue. To clean the injector, remove it from the pressure washer and soak it in a solution of warm water and dish soap.
A faulty injector The injector may be faulty if it is not opening or closing properly. To check the injector, connect it to a pressure washer and turn on the water. If the injector does not open or close, it will need to be replaced.
A problem with the pressure washer The pressure washer may not be generating enough pressure to operate the injector. To check the pressure, connect a pressure gauge to the pressure washer and turn on the water. If the pressure is too low, the pressure washer will need to be repaired or replaced.