How to Winterize Pressure Washer Step by Step Guide

Last Updated on November 10, 2026 by D. Ruddy

As temperatures drop, properly storing your pressure washer becomes crucial to prevent freeze damage. Learning how to winterize pressure washer units ensures they start up smoothly next season without cracked pumps or damaged hoses. This guide covers all the essential steps to protect your equipment from winter’s harsh effects.

To winterize your pressure washer, drain all water from the system, add antifreeze to the pump, and store it in a dry place. This prevents freezing and extends your machine’s lifespan.

What You Need for Winterizing

Before you begin, gather all the necessary supplies to make the process smooth and efficient. Having everything on hand prevents interruptions and ensures you don’t miss any critical steps.

Here’s what you’ll need:

• Pressure washer owner’s manual (for model-specific instructions)
• Pump saver or RV antifreeze (non-toxic, propylene glycol based)
• Garden hose and water source
• Bucket or container for catching water
• Wrench set (for disconnecting fittings if needed)
• Soft cloth or towel
• Storage cover or tarp

Tip: Use only non-toxic antifreeze designed for pressure washers. Automotive antifreeze contains harmful chemicals that can damage your machine.

Step 1 Flush the System with Clean Water

Start by thoroughly flushing your pressure washer to remove any detergent or debris from the system. This prevents clogs and ensures clean water circulates during the winterizing process.

Follow these steps:

1. Connect your pressure washer to a clean water source using the garden hose
2. Turn on the water supply and let it run for 1-2 minutes without the engine running
3. Start the pressure washer engine and let it run for 3-5 minutes with the spray wand engaged
4. Switch between all nozzle settings to ensure water flows through every part of the system
5. Turn off the engine and disconnect the water supply

This step is crucial for removing any soap residue or dirt that could mix with the antifreeze and cause issues later.

Step 2 Drain All Water from the System

Water left in your pressure washer will freeze and expand, potentially cracking the pump, hoses, or other components. Complete drainage is the most important part of winterizing.

Here’s how to do it properly:

1. Disconnect all hoses and attachments from the pressure washer
2. Drain the water tank completely by tilting the machine or using the drain plug if available
3. Engage the spray trigger to release pressure and drain water from the pump and hose
4. Remove the spark plug and pull the starter cord a few times to clear any remaining water from the pump
5. Check the pump housing and other components for any standing water

Warning: Never store your pressure washer with water in the system, even for a few days. Freezing can occur at temperatures as high as 32°F (0°C).

Step 3 Add Antifreeze to the Pump

After draining all water, add antifreeze to protect the internal components from any residual moisture that might freeze. Use only non-toxic, propylene glycol-based antifreeze designed for pressure washers.

Follow these steps:

1. Locate the pump inlet (refer to your owner’s manual if unsure)
2. Pour about 1-2 cups of pump saver or RV antifreeze into the inlet
3. Reconnect the water inlet hose and turn on the water supply briefly to help distribute the antifreeze
4. Engage the spray trigger for a few seconds to circulate the antifreeze through the system
5. Disconnect the water supply and drain any excess antifreeze

According to pressure washer manufacturers, using the right amount of antifreeze can prevent up to 95% of winter-related damage to your equipment.

Step 4 Protect the Engine and Fuel System

For gas-powered pressure washers, proper engine preparation is just as important as protecting the pump and hoses. Fuel left in the system can degrade and cause starting problems next season.

Here’s what to do:

• For 4-stroke engines: Add a fuel stabilizer to the gas tank and run the engine for a few minutes to circulate it. Then, either drain the fuel completely or fill the tank to the top to prevent condensation.
• For 2-stroke engines: Mix fresh fuel with the proper oil ratio and run the engine until the fuel system is empty. Never leave old mixed fuel in the system.
• For electric models: Simply ensure the unit is completely dry before storage.
• Change the engine oil if it’s dirty or if you won’t be using the pressure washer for several months.
• Remove the spark plug, add a small amount of oil to the cylinder, and pull the starter cord a few times to coat the internal components.
• Replace the spark plug and ensure it’s properly gapped.

Important: According to the Outdoor Power Equipment Institute, ethanol-blended fuels can attract moisture and cause corrosion. Always use fresh, ethanol-free fuel when possible.

Step 5 Prepare Hoses and Accessories

Don’t forget about the hoses, nozzles, and other accessories that come with your pressure washer. These also need proper care to ensure they last through the winter.

Follow these steps for each component:

• Hoses: Completely drain all water, then coil neatly and hang or store in a dry place. Avoid sharp bends that could damage the hose.
• Nozzles: Clean each nozzle with warm, soapy water and a soft brush. Rinse thoroughly and dry completely before storage.
• Spray Gun/Wand: Disconnect and clean the spray gun and wand. Ensure all water is drained and the trigger moves freely.
• Detergent Tank: Empty, clean, and dry the detergent tank completely to prevent residue buildup.
• Wheels and Frame: Clean the pressure washer frame and wheels. Check for any loose bolts or damage that needs repair.

Step 6 Choose the Right Storage Location

Where you store your pressure washer is just as important as how you prepare it. The ideal storage location protects your equipment from the elements and temperature extremes.

Consider these storage options:

• Indoor Storage: A garage, shed, or basement is ideal. Ensure the area is dry and well-ventilated, especially for gas-powered models.
• Covered Outdoor Storage: If indoor storage isn’t available, use a waterproof cover and store the pressure washer under a covered patio or awning.
• Temperature Control: Avoid areas that get extremely cold or hot. Temperature fluctuations can cause condensation inside the pump.
• Elevated Storage: Store the pressure washer off the ground on a shelf or pallet to prevent moisture absorption and protect from potential flooding.

Tip: If storing in an unheated area, consider adding a small moisture absorber near your pressure washer to reduce humidity in the storage space.

Common Mistakes to Avoid

Even with good intentions, many people make mistakes when winterizing their pressure washers. Being aware of these common pitfalls can help you avoid costly damage to your equipment.

1. Skipping the Manual: Every pressure washer model has specific requirements. Always consult your owner’s manual for manufacturer recommendations.
2. Using Automotive Antifreeze: This contains ethylene glycol, which is toxic and can damage your pressure washer’s seals and components.
3. Not Draining All Water: Even a small amount of water can freeze and cause damage. Be thorough in your drainage process.
4. Storing with Fuel in the Tank: Old fuel can gum up the carburetor and make starting difficult next season. Either drain the fuel or use a fuel stabilizer.
5. Ignoring the Hoses: Hoses can crack if not properly drained and stored. Don’t forget this crucial component.
6. Storing in a Damp Location: Moisture is the enemy of pressure washers. Always store in a dry place and use a cover if needed.
7. Forgetting to Lubricate: Moving parts need lubrication to prevent rust and corrosion during storage.

The Pressure Washer Manufacturers’ Association reports that improper winterization causes over 60% of all pressure washer repairs in the spring. Taking the time to do it right can save you hundreds in repair costs.

Maintenance Tips for Long-Term Storage

If you won’t be using your pressure washer for several months, there are additional maintenance steps you can take to ensure it stays in top condition.

Consider these long-term storage tips:

• Monthly Checks: If possible, check on your stored pressure washer monthly. Look for any signs of moisture, pests, or damage.
• Run the Engine: For gas models, start the engine and let it run for 5-10 minutes every month or two. This keeps the seals lubricated and prevents fuel system issues.
• Inspect Hoses: Check hoses for any signs of cracking or dry rot. Replace if necessary before the next use.
• Update Records: Keep a maintenance log of when you performed winterization and any other services. This helps track your pressure washer’s care history.
• Pest Prevention: Place mothballs or other pest deterrents near your stored equipment to prevent rodents from nesting in or chewing on components.

Frequently Asked Questions

How often should I winterize my pressure washer?

You should winterize your pressure washer whenever you expect temperatures to drop below freezing (32°F or 0°C). In most climates, this means performing the process once in late fall before winter sets in.

Can I use regular antifreeze for my pressure washer?

No, you should never use automotive antifreeze. It contains ethylene glycol, which is toxic and can damage your pressure washer’s components. Always use non-toxic, propylene glycol-based antifreeze designed for pressure washers or RV systems.

What happens if I don’t winterize my pressure washer?

If you don’t winterize your pressure washer, any water left in the system can freeze and expand, causing cracks in the pump, hoses, or other components. This can lead to costly repairs or even require complete replacement of parts.

How long does it take to winterize a pressure washer?

The entire process typically takes about 30-45 minutes, depending on your pressure washer’s size and complexity. This includes draining the system, adding antifreeze, and preparing all accessories for storage.

Can I store my pressure washer outside in winter?

While it’s possible to store your pressure washer outside, it’s not recommended. If you must store it outside, use a high-quality, waterproof cover and ensure the unit is elevated off the ground. However, indoor storage in a dry, temperature-controlled environment is always best.

Final Thoughts

Properly winterizing your pressure washer is a straightforward process that can save you from expensive repairs and extend the life of your equipment. By following these steps to drain water, add antifreeze, prepare the engine, and store your machine correctly, you’ll ensure it’s ready to go when you need it next season. Remember, an ounce of prevention is worth a pound of cure when it comes to pressure washer maintenance.