How to Clear Water from Your Pressure Washer

Why water stays trapped in your pressure washer and how to drain it

Water left inside a pressure washer can freeze in winter, rust internal parts, or grow mold and bacteria during storage. Clearing the system properly takes about 15 minutes and prevents damage that costs far more than the time spent. The process differs slightly depending on whether your machine is gas-powered or electric, and whether it has a heating element.

Most pressure washers hold water in the pump, hoses, and gun even after you stop using them. If you live in South Carolina where winter temperatures can dip below freezing—particularly in the Upstate around Greenville and Spartanburg—trapped water will expand and crack the pump. Even in milder coastal areas, standing water breeds bacteria and mineral buildup that clogs nozzles and reduces pressure over time.

Key Takeaways

• Drain the pump by running the machine without water pressure for 30 seconds to push out trapped water and detergent.
• Disconnect hoses and hold them upright or at an angle to let water drain completely into a bucket or drain.
• Store the gun and nozzles separately with the trigger locked in the off position to prevent accidental spray.
• In freezing weather, use a pump protectant fluid designed for pressure washers to prevent ice damage during winter storage.
• Check your owner's manual for model-specific steps, as some machines have drain plugs or winterization ports that others lack.

Draining the pump on gas and electric models

Start by turning off the machine and letting it cool for at least five minutes. Disconnect the water supply hose from the inlet. On a gas model, turn the fuel valve to the off position; on electric models, unplug the cord from the outlet.

Locate the pump drain plug—usually a small bolt or cap on the bottom or side of the pump housing. Place a bucket underneath and turn the plug counterclockwise by hand or with a wrench, depending on your model. Water and old detergent will flow out. Once the flow stops, wipe the plug clean and reinstall it hand-tight; do not over-tighten, as this can strip the threads.

If your model has no visible drain plug, run the machine at low pressure for 30 seconds with no water connected to the inlet. This forces residual water through the pump and out the discharge port. Repeat this step twice to ensure the pump is as dry as possible.

Clearing hoses and the spray gun

Disconnect the high-pressure hose from both the machine outlet and the spray gun. Hold the hose vertically or at a steep angle and let water drain into a bucket. Gently shake the hose or walk it in a circle to encourage water to flow out. For hoses longer than 25 feet, you may need to coil them in a way that allows water to drain toward one end.

Disconnect the low-pressure inlet hose as well and drain it the same way. These hoses often trap more water than the high-pressure line because they sit at a lower angle during storage.

For the spray gun, point it downward into a bucket and pull the trigger several times to expel water. Lock the trigger in the off position using the safety mechanism on your model—usually a small lever or button near the handle. Store the gun separately from the hoses to allow air circulation and faster drying.

Removing nozzles and cleaning the discharge port

Unscrew the nozzle from the end of the spray gun and hold it over a sink or bucket. Run water through it by hand or use a small brush to clear any mineral deposits or debris. Nozzles are precision parts; do not soak them in vinegar or use harsh chemicals unless your manual specifically recommends it, as this can damage the internal orifice.

Inspect the discharge port on the machine—where the high-pressure hose connects—for water droplets or mineral buildup. Wipe it dry with a clean cloth. If you see white crusty deposits, this is mineral scale from hard water. You can gently scrub it with a soft brush, but avoid forcing anything into the port itself.

Store nozzles in a dry container indoors, separate from the machine. This protects them from weather and makes them easier to find when you need them next.

Winterization for freezing climates

If you store your pressure washer outdoors or in an unheated shed during winter months, use a pump protectant fluid designed for pressure washers. These products contain antifreeze and corrosion inhibitors that protect the pump and internal seals. Common brands include Briggs & Stratton Pump Protectant and Generac Winterization Kit, though your machine's manual may recommend a specific product.

To apply protectant, connect the low-pressure inlet hose to the machine but do not connect the high-pressure hose. Place the inlet hose into a bucket containing the protectant fluid. Run the machine at low pressure for 15 to 20 seconds, allowing the fluid to circulate through the pump. Stop the machine and let it sit for a few minutes, then drain any excess fluid from the pump using the drain plug method described above.

This step is especially important if you live in the Upstate or mountain regions of South Carolina where winter temperatures regularly fall below 32 degrees Fahrenheit. Coastal areas rarely need this step, but it does not hurt to use protectant if you plan to store the machine for more than three months.

Storage tips to keep your machine ready

Store your pressure washer in a dry location—a garage, shed, or covered porch works well. Keep it away from direct sunlight, which can degrade hoses and seals over time. Coil hoses loosely rather than tightly wrapping them, as tight coils can kink and trap water.

Before storing for the season, run the machine one final time with no water connected to the inlet. This ensures any remaining moisture is expelled. If your machine has a fuel tank, run it until the tank is nearly empty or add fuel stabilizer according to the manual; old fuel can gum up the carburetor and make the engine hard to start in spring.

Keep your owner's manual and any warranty paperwork in a waterproof bag stored with the machine. When you pull it out to use again, you will have the information you need to troubleshoot any issues.

Frequently Asked Questions

Can I leave water in the pressure washer if I use it every week?

If you use the machine at least once a week, you do not need to drain it completely each time. However, if you will not use it for more than two weeks, drain the pump and hoses to prevent bacterial growth and mineral buildup. In winter, drain it regardless of use frequency to avoid freeze damage.

What should I do if water is still coming out after I drain the pump?

This is normal—small amounts of water remain in the pump housing and hoses even after draining. If water continues to flow heavily after 30 seconds of running the machine dry, check that the drain plug is fully open and that you have disconnected the inlet hose. If water still flows, contact the manufacturer, as this may indicate a valve problem.

Do I need to drain the machine if I store it indoors in a heated garage?

Draining is still recommended even in heated storage, as standing water can rust internal parts and grow bacteria. The main risk of freeze damage is eliminated in a heated space, but mineral deposits and corrosion can still occur over months of storage. A quick drain takes 15 minutes and extends the life of your machine.

Can I use compressed air to blow water out of the hoses?

Yes, compressed air can speed up the drying process. Use low pressure—around 30 to 40 PSI—and direct the air through the hoses into a bucket or drain. Do not use high-pressure air, as this can damage internal seals or force water into parts of the machine where it is harder to remove.

What if I forgot to drain my pressure washer and it froze?

Do not attempt to run a frozen machine, as this can crack the pump or damage the engine. Move it to a warm location—indoors or in a heated garage—and let it thaw completely, which may take several hours. Once thawed, drain it using the steps above and run it at low pressure for a minute to check for leaks before resuming normal use.