The answer to 'why is my pressure washer stained' is that there are a few common causes, including mineral buildup, corrosion, or improper storage. Mineral deposits from hard water can leave behind stains on the surface of your pressure washer. Over time, the metal components can also corrode and discolor the exterior. Additionally, if you don't properly clean and store your pressure washer after each use, it can lead to staining and discoloration.
To fix a stained pressure washer, you'll first want to identify the root cause. Try cleaning the exterior with a mild detergent and water. For more stubborn stains, you may need to use a pressure washer cleaning solution or vinegar. If the staining is due to corrosion, you may need to sand and repaint the affected areas. In some cases, you may need to call a professional pressure washer repair service if the staining is severe or you're not comfortable fixing it yourself.