Safety first: Unplug the machine and remove the clean water tank to stop further flow.

Relieve pressure: With the machine unplugged and tank removed, squeeze the trigger several times to release any residual pressure in the solution line.
Inspect trigger: Check that the trigger returns fully when released. If it feels loose or does not spring back, the return spring or linkage may be damaged.
Clean around trigger and valve: Wipe away any dried detergent or sticky residue around the trigger area. Detergent build-up can cause the mechanism to stick.
Valve service (advanced): On some models, the solution valve can be accessed by removing the handle cover. Carefully clean the valve body and seat with a damp cloth. Do not use oils or lubricants that can damage seals.
Replace if necessary: If solution still flows without trigger input, the valve assembly may be worn and should be replaced.

Solution sprays continuously even when trigger is released

Possible Causes