How to Drain Gas from a Pressure Washer (Complete Step-by-Step Guide)

If you've ever had trouble starting your pressure washer after it sat idle for a while, chances are old fuel was the culprit. Over time, gasoline breaks down and forms sticky deposits that can clog carburetors and fuel lines—leading to hard starts or even complete failure.

That’s why draining the gas tank is essential for routine maintenance and long-term storage.

This complete guide shows you exactly how to do it safely, easily, and effectively—so your washer stays in peak shape.

🚨 Why Draining Gas Is So Important

Prevents clogs and varnish build-up in fuel systems

Avoids corrosion and damage to internal parts

Ensures smooth startups even after months of storage

Extends the life of your pressure washer

Gas left in the tank for more than 30 days can degrade and gum up your engine—a problem that’s easily avoidable with this simple process.

🛠️ What You’ll Need:

A fuel-safe container for collecting old gas

A siphon pump (manual or battery-operated) OR a basic tube for gravity draining

Gloves and goggles for protection

A fuel stabilizer (optional, but great for preventing degradation if storing fuel)

✅ Step-by-Step Instructions:

1️. Cool Down Completely:

Make sure your pressure washer is fully cooled before starting. Never work with fuel around a hot engine.

2️. Locate the Fuel Tank & Valve:

Find the gas tank (usually mounted near the engine) and check for an inline fuel valve—if it has one, this makes draining easier.

3️. Siphon or Disconnect:

Use your siphon pump to draw out the gas into your container. If your washer has a removable fuel line, you can carefully disconnect it and let gravity do the work.

4️. Run the Engine Dry:

Once the tank is empty, restart the engine and let it run until it shuts off—this clears out any remaining fuel in the carburetor and lines.

5️. Inspect & Clean:

Take this chance to check your fuel filter and hoses for signs of wear or clogging. Replace if necessary.

6️. Dispose of Fuel Properly:

Don’t just toss old gas down a drain. Bring it to a hazardous waste facility or follow your local disposal guidelines.

🔧 Pro Tips for Long-Term Care:

✔ Always use fresh fuel when restarting your machine.

✔ Add a fuel stabilizer to prevent breakdown if storing for under 30 days.

✔ Check the oil and air filter while you’re at it—preventive maintenance is your washer’s best friend.

✔ Keep a regular draining schedule if you use your washer seasonally.

🧠 Common Mistakes to Avoid:

✘ Skipping the carburetor drain: Fuel left inside can still cause gumming even if the tank is empty.

✘ Draining near open flames: Always work in a well-ventilated area away from ignition sources.

✘ Leaving stale gas in the container too long: Properly dispose of old fuel soon after draining.

👉 Full how-to guide with photos and safety tips: How to Drain Gas from a Pressure Washer?