Summarize:

Water and electricity do not mix, and it is dangerous to get electrical equipment wet. Don't use your power washer anywhere near electrical equipment or active power lines. If you have to wash an area with an exterior outlet, cover it with multiple layers of duct tape to keep water out. Keep your washer's engine behind you as you move around during your pressure washing. This will keep water from getting in the engine. Pressure washers obviously produce quite a bit of force. Even if you don't hit sensitive areas with the pressure washer directly, the ricocheting water can still cause damage. Cover areas that you wish to protect with a heavy drop cloth. Lay it on top of the area you want to protect, and weigh down the corners with heavy objects or tie it down with duct tape. A drop cloth will not protect sensitive areas if you aim your nozzle directly at them. It will merely prevent incidental damage from unwanted splashing. Pressure washers create a lot of kickback when you turn them on. For this reason, using the washer on a ladder or unstable surface can be extremely dangerous. Besides, pressure washers are strong and you should be able to hit a hard-to-reach area with higher power settings and a thinner nozzle from 1030 feet (3.09.1m) away. If you're using a soap dispenser, soap scum can dry up in your water lines after you're done using your washer. Clean your pressure washer by refilling it with water and running it for 3-5 minutes before emptying the tank and wiping it down with a microfiber cloth. Inspect the lines and hoses on your washer for damage before each use. Some pressure washers are designed to be taken apart for cleaning. Refer to your washer's manual to see how to take it apart. If you have a gas-powered washer, you may need to change out the oil regularly. Store your pressure washer in a warmed section of your home during the winter to prevent water lines from freezing.
Avoid electrical lines, outlets, and light sources. Cover shrubs, gardens, or air conditioners with drop cloths. Don't use your pressure washer on a ladder or unstable surface. Clean out water lines after using soap in your pressure washer.