How to Winterize Your Pressure Washer in 10 Easy Steps

As colder months roll in, many contractors across the U.S. are preparing for the offseason. Just like any other piece of pro-grade equipment, your pressure washer needs the right care before it goes into storage. Winterizing isn’t just a “good idea”,  it’s essential to protect your pump, engine, and fuel system from damage caused by improper storage.

At Spraywell, we’ve helped countless professionals extend the life of their rigs by following a consistent winterization process. Below, you’ll find two detailed checklists: one for short-term storage (under two months) and one for long-term storage (over two months).

Short-Term Storage (Less Than Two Months)

If you’re pausing operations for a few weeks but plan to fire your unit back up soon, follow these 10 steps:

1. Fill the fuel tank with fresh gasoline and add the manufacturer-recommended stabilizer.
   
   
2. Connect your hoses, turn the water on, and purge all air from the system.
   
   
3. Start your unit and run it for 10 minutes, occasionally squeezing the trigger to prevent pump overheating. This circulates stabilized fuel throughout the system.
   
   
4. Turn the unit off.
   
   
5. Shut off the water source, release built-up pressure by squeezing the trigger, and disconnect all hoses.
   
   
6. Allow the engine to cool completely before moving on.
   
   
7. Protect the pump by attaching a pump saver to the garden hose input. Press until water and protector fluid exit the high-pressure port, then remove.
   
   
8. Wipe down the machine with a damp cloth, then dry thoroughly.
   
   
9. Touch up exposed metal with paint and apply a light oil film to prevent rust.
   
   
10. Store in a clean, dry space, away from direct sunlight.
    
    

Long-Term Storage (More Than Two Months)

For extended storage, these extra steps will safeguard your pressure washer until the next season:

1. Turn the unit off, disconnect hoses, and release pressure from the gun.
   
   
2. Drain the oil completely.
   
   
3. Let the engine cool before further work.
   
   
4. Drain the fuel system, empty the tank, carburetor, and fuel lines.
   
   
5. Clean around the spark plug, then remove it.
   
   
6. Add 0.5 oz (15 mL) of oil into the combustion chamber, then pull the recoil slowly twice to distribute.
   
   
7. Install a new spark plug.
   
   
8. Protect the pump with a pump saver as outlined above.
   
   
9. Wipe down the entire unit, apply touch-up paint, and lightly oil any rust-prone spots.
   
   
10. Store in a cool, dry location, away from sun or moisture.
    
    

Why Winterization Matters

Skipping these steps may save time today, but it often leads to clogged carburetors, corroded pumps, rust, and costly downtime when spring arrives. By taking an hour now, you protect your investment and ensure your pressure washer starts strong next season.

In our experience, contractors who make winterization part of their annual routine get longer life from their rigs, fewer costly repairs, and more uptime when it matters most.

Final Thoughts

Whether you’re taking a short break or shutting down for the full offseason, properly winterizing your pressure washer is one of the best ways to safeguard your equipment. Follow these 10 steps each year, and your rig will be ready to perform at its peak when work ramps back up.

Need help with technical questions or choosing the right stabilizer? Call Spraywell today! Our team of experienced technicians is here to help you keep your equipment in top shape, season after season!