How to Winterize Your Pressure Washer: Complete UK Guide

Protect Your Investment from Frost Damage

In the UK, winter frost can destroy an improperly stored pressure washer in a single night. Water left in the pump, hoses, or spray gun will freeze, expand, and crack expensive components. This guide shows you exactly how to winterize your pressure washer properly.

Why Winterization is Critical

Water expands by approximately 9% when it freezes. In the confined spaces of your pressure washer's pump, this expansion creates enormous pressure that cracks pump housings, destroys seals, and splits hoses. A single freeze can cause hundreds of pounds in damage.

Even if you store your machine in a garage or shed, UK winter temperatures regularly drop below freezing. Unless your storage area is heated, you must winterize.

When to Winterize

Winterize your pressure washer when:

• You won't be using it for more than 2 weeks during winter months
• Overnight temperatures are forecast to drop below 0°C
• You're storing it in an unheated location
• The season is ending (typically late October/November in the UK)

Complete Winterization Process

Step 1: Final Clean

Before winterizing, give your pressure washer a final clean:

• Flush the system with clean water
• Remove any dirt or debris from the exterior
• Clean the inlet filter
• Wipe down all surfaces

Step 2: Drain All Water

This is the most critical step:

1. Disconnect the water supply
2. Turn off the machine
3. Squeeze the trigger gun to release pressure
4. Disconnect all hoses
5. Tip the machine at various angles to drain water from the pump
6. Squeeze the trigger repeatedly to expel water from the spray gun

Step 3: Use Pump Saver/Antifreeze

Even after draining, some water remains in the pump. Use a pump saver product:

1. Attach the pump saver bottle to the water inlet
2. Squeeze the bottle while pulling the starter cord (petrol) or briefly running the motor (electric)
3. Continue until antifreeze solution comes out of the spray gun
4. This coats internal components and prevents any remaining water from freezing

Recommended products: We stock pump saver antifreeze suitable for all pressure washer brands.

Step 4: Petrol Engine Winterization

For BOSS BOYS, RealKleen, and other petrol pressure washers:

Option A - Fuel Stabilizer (Recommended):

• Add fuel stabilizer to a full tank of petrol
• Run the engine for 5 minutes to circulate stabilizer
• This prevents fuel degradation and carburetor gumming

Option B - Complete Fuel Drain:

• Run the engine until the tank is empty
• Drain the carburetor bowl
• This prevents stale fuel issues but requires refueling in spring

Step 5: Engine Oil Service

Change the engine oil before winter storage:

• Used oil contains contaminants and moisture
• Fresh oil protects internal components during storage
• It's ready to go when spring arrives

Step 6: Spark Plug Care

For petrol models:

• Remove the spark plug
• Add a small amount of engine oil into the cylinder
• Pull the starter cord a few times to distribute oil
• Replace the spark plug (don't reconnect the lead)

Hot Water Pressure Washer Winterization

Hot water models like Kranzle Therm or BOSS BOYS MHD series require additional steps:

Burner System

• Drain the fuel tank or add diesel stabilizer
• Clean the burner nozzle
• Check and clean the combustion chamber

Boiler/Heat Exchanger

• Completely drain the heating coil
• Use pump saver through the entire system
• Some models have specific drain points - check your manual

Storage Best Practices

Location

• Ideal: Heated building or indoor storage
• Acceptable: Unheated garage/shed (if properly winterized)
• Avoid: Outdoor storage, even under covers

Position

• Store on a level surface
• Keep upright (don't lay on side)
• Ensure good ventilation to prevent moisture buildup
• Cover with a breathable cover (not plastic sheeting)

Accessories

• Coil hoses loosely and hang or store flat
• Store spray guns and lances separately
• Keep nozzles in a container to prevent loss
• Store detergent bottles separately

Spring Start-Up Checklist

When bringing your pressure washer out of winter storage:

1. Visual inspection for any damage or leaks
2. Check all hoses and connections
3. Reconnect spark plug lead (petrol models)
4. Check engine oil level
5. Check pump oil level
6. Refuel if you drained the tank
7. Connect water supply and test for leaks
8. Run for a few minutes before taking on jobs

Common Winterization Mistakes

1. Assuming the Garage is Warm Enough

Even attached garages can drop below freezing. Always winterize unless the space is heated.

2. Skipping Pump Saver

Draining alone isn't enough. Pump saver provides crucial protection for remaining water and lubricates seals.

3. Leaving Hoses Connected

Water trapped in hoses will freeze and split them. Always disconnect and drain.

4. Forgetting the Spray Gun

Water trapped in the trigger gun will freeze and damage the mechanism. Always squeeze the trigger multiple times after draining.

Professional Winterization Service

Don't have time or confidence to winterize properly? RealKleen offers professional winterization services including:

• Complete system drainage
• Pump saver application
• Engine servicing
• Full inspection
• Safe storage options available

Conclusion

Proper winterization takes just 30 minutes but can save you hundreds of pounds in frost damage repairs. Don't risk your investment - follow this guide or contact RealKleen for professional winterization service.

Remember: It only takes one freeze to destroy a pressure washer. When in doubt, winterize!