The answer to tough stains on a pressure washer is that there are a few common causes, including built-up grime, dried-on debris, and mineral deposits. Symptoms may include poor cleaning performance, streaking, or the pressure washer leaving behind residue.
To address tough stains, start by thoroughly cleaning the pressure washer wand, nozzle, and other components. Use a dedicated pressure washer cleaner or a mild detergent and warm water. If that doesn't work, you may need to soak the affected parts in a degreasing solution or use a stiff brush to scrub away the stains. For stubborn mineral deposits, a vinegar or citric acid solution can help break them down. If the stains persist, it's best to call in a professional cleaning service to properly diagnose and resolve the issue.