How to Maintain a Pressure Washer

Check the water inlet screen, located where you connect the garden hose. If the screen is dirty, clean it with water. Replace it if it’s damaged. If your pressure washer is equipped with an inline screen in the wand extension, make sure it’s not clogged. Clean it with water or replace it if it’s damaged.

Inspect the spray gun and wand extension as well as the nozzle or spray tip. Make sure the connections are secure, including the connection to the high-pressure hose. Test the spray gun trigger and trigger lock. If they don’t function correctly, replace the spray gun. Examine the high-pressure hose for cuts, leaks, bulges or other damage, and check the hose couplings. If the hose is damaged, follow the manufacturer’s replacement instructions.

Check the detergent siphoning tube and clean it out if it’s clogged. If the detergent system has a filter, check it as well.

Flush out the garden hose before you connect it to the pressure washer.

Turn off the pressure washer and the water supply. If you have an electric pressure washer, unplug it from the electrical outlet. Point the spray gun away from any people or animals and run it until the water stops flowing. Engage the trigger lock and let the pressure washer cool down.

Disconnect the garden hose, spray gun, wand extension and high-pressure hose. Drain water from them. Follow the manufacturer’s instructions to remove any remaining water from the pump. Clean off any debris from the machine.

Check the spark plug for damage. Before removing the plug, clean the area around it to prevent debris from falling into the engine’s combustion chamber. Remove the plug and replace it with a new plug if you find cracks or if the electrodes look burned or pitted. Before reinstalling the plug or installing a new one, check the electrode gap with a gap tool or feeler gauge, and adjust as recommended in your manual.

Check the air filter. Clean or replace it with a new filter as needed. If you have a reusable foam filter, refer to your manual for cleaning instructions. If your machine uses a paper filter and it’s dirty, replace it.

Follow the pressure washer manufacturer’s recommendations for fuel and fuel additives. Use gasoline that’s less than 30 days old. Gas bought at the pump degrades over time and can lead to corrosion and the formation of varnish in the engine and fuel system. 

Your manual may recommend using a fuel stabilizer that prevents engine corrosion and keeps gasoline fresh. Ethanol-free, pre-mixed fuel is an alternative that stays fresh longer than pump gasoline. See our guide to fueling outdoor power equipment for tips on keeping a gasoline engine running smoothly.

If you didn’t treat the fuel in a gasoline-powered pressure washer with a stabilizer, drain it into an approved gasoline container. Run the pressure washer until the engine stops from lack of fuel. Contact your local recycling center for instructions on how to dispose of gasoline.

Store the pressure washer in a dry area, protected from freezing temperatures and other extreme weather. Keep it away from heat sources that could dry out the pump seals or ignite fuel vapors. Use a pump lubricant/antifreeze. In addition to lubricating seals and pistons and protecting against freezing, the solution helps prevent damage from mineral deposits. Protect the pressure washer with a cover that doesn’t hold in moisture.