How to Winterize a Pressure Washer with DIY Pump Saver

Last updated on December 9th, 2018

Winter is here again! Time to pull out the coats, stash the motorcycle ’till next season…and properly store some tools. Certainly not the funnest task in the world, but one worth doing nonetheless. You should winterize a pressure washer for one main purpose – To make sure it works the next time you need to use it.

Commercial winterizing products to winterize a pressure washer can cost over 400$ per gallon, if you buy them at around 12-20$ per 4 Fl Oz. I’m not even joking. Calculate it yourself, it really would cost that much per gallon! Here I’m going to show you how to make something just as good, if not better. At around 3$ per gallon. Keep reading to see if the solution convinces you or not.

Let’s begin!

Difficulty: Easy
Tool Requirements: Basic
Time: 20 Minutes
Cost: 5$

Why winterize a pressure washer at all?

How to Winterize a Pressure Washer - Winter is coming meme

Depending on where you live, you should winterize a pressure washer for one or more purposes:

  • To keep frozen water from over-pressurizing and damaging the water pump.
  • Avoid the pump internals rusting.
  • To keep mineral deposits from forming and degrading or destroying seals.
  • To ensure the pump surfaces stay lubricated for longer life on start-up.

A proper winterizing solution has to do all of that. And by the way, it applies regardless of the pressure washer being electric or gasoline powered.Even if you live somewhere without freezing temperatures, the rust, deposits and lubrication aspects would still apply to you. Basically, you could substitute “winterize” for “long-term storage” just the same.

The easiest way to take care of most things on that list is to empty the water pump before putting it away. However, that still leaves the option of rust and mineral deposits which will tear or damage seals in the long run. Nonetheless, for short-term protection against freezing it’s the easiest option and what I’d do.

What’s the best way to store a power washer long-term?

If you know you won’t be using the pressure washer for a while, and you want to take proper care of your pressure washer for the best longevity, you are going to want to use something that tackles all of those issues. But if you’re like me, you probably don’t really know if you’ll be firing up the pressure washer next week or in four months.

If that’s the case, you’ll never find a moment to waste a 10$ bottle of “Pressure Washer Pump Saver”. You’ll always save it for next time. Plus, the commercial options are a pain to apply right. In my opinion, for a product like this to be worth it, it has to be cheap enough to apply without concern about it being costly.

And done right, it really is worthwhile. The pump portion of your pressure washer can and will break or deteriorate if neglected. I replaced one not long ago. If you’re lucky, you can simply repair it for around 60-100$ bucks. But on most models these days that isn’t even possible. Winterizing it is just cheap insurance.

And that’s where this How-To comes in. Here’s the best homemade solution to winterize a pressure washer.

What you’ll need

RV Antifreeze

RV Antifreeze is used to winterize a RV’s water lines (potable water lines, not in the engine). It’s main difference with normal antifreeze is that it is non-toxic and biodegradable, making it perfect for a pressure washer. The components are Ethyl Alcohol (anti-freeze, disinfectant?), Propylene Glycol (anti-freeze), Water, Di Potassium Phosphate (buffer), Colorant and a Fragrance.

On its own, it won’t provide much anti-rust properties (though it displaces oxygen). But it’s excellent as a non-toxic antifreeze. Finally, it’s dirt cheap at around 2-5$ per gallon if you look around for it. Online it might cost more due to shipping. Not all brick and mortar stores have it (and if they do, some over charge). To find it the cheapest I’d suggest looking at Walmart.

Note: As an alternative you could use regular antifreeze, but it’s going to be more expensive and toxic (though not a huge concern for the small quantities used).

Water Pump Lube

I used Bar’s Leaks Water Pump Lube w/ Anti Rust (the same stuff I use in my car). You should just use which ever is cheaper. The key words are “Anti-Rust” and “Lube”. Don’t simply buy a “Coolant additive”. That’s not what you’re looking for. The purpose of this is to provide extra lubrication and corrosion protection, while being water-soluble. Which is why we can’t use any “normal” oil…pesky molecular polarity. If you search around it should cost you somewhere in the 3-6$ range for a 12oz bottle, which is good for 1-3 gallons of coolant. That way you can use it for the winterizing solution and to put the remainder in your car if you like.

Here are a few other things we’ll need.

  • A Funnel – A large reservoir-funnel with a hose attached is going to be the easiest way to do this, since you can attach it directly to the pump’s inlet.
  • Hose Repair Kit – This is needed in order to connect the funnel’s hose to a garden hose thread.
  • Connectors and Shut-Off Valve – You’ll need some connectors to connect the funnel to the pressure washer’s inlet, as well as a way to stop the flow before removing it to avoid waste.
  • Heat Gun – To heat the hose and make it pliable. I used a flameless lighter, but a hair dryer or lighter is a perfect substitute.

At around 3$ for a gallon of RV Antifreeze, and 4$ for a bottle of water pump additive (of which you only need one-third or so), you’ll have made a gallon of the solution for around 5$. That’s enough to winterize a pressure washer every time they won’t be used for years to come. Sure beats the one or two-use commercial option at over 10 bucks.

How to winterize a pressure washer – Step by Step

Step 1 – Assemble the funnel

The first step is to assemble the funnel to make it connect to the pressure washer’s inlet.

As you can see from the pictures, I used an automotive funnel. It’s perfect for this application as it can hold around one liter (a quarter gallon) of solution and has a filter to avoid debris getting in the pump. My pressure washers also have quick connector attachments, so I needed one of those for it. And to keep the liquid inside the funnel’s hose from being wasted, I put a shut off at the very end.

Depending on your application, assemble it however is suitable for your needs.

Step 2 – Attach the funnel and fill it

If the pressure washer is electric, you can get away with holding the funnel while circulating the fluid.

If your pressure washer is gasoline-powered, you’ll need someone to hold the funnel. Or at least attach it somehow to the pressure washer’s frame so it doesn’t spill.

Then fill it up. You want to fill it with more than you intend to use. You can simply pour the excess pump saver solution back into the bottle later.

Step 3 – Circulate the pump saver solution

The purpose of the pump saver solution is to displace the regular water inside pressure washer’s water pump.

If your pressure washer is electric, turn it on a few seconds until you’ve flushed the water inside the pump and undiluted solution is coming out of the outlet. It should only take a few seconds. You don’t have to waste more than needed.

If your pressure washer is gasoline-powered, with the power switch off, pull the starter cable until you’ve flushed the water inside the pump out. Stop once the undiluted solution is coming out of the pressure washer’s outlet. It should take you somewhere between 3-10 full pulls, but no more.

Once you’re satisfied, close the valve on the hose-end and remove the funnel. You can simply put the unused solution back in the container. Here you can see the fluid still inside the pressure washer’s brass filter. That’s another great accessory to make sure your pressure washer lives a long life.

Do we leave the anti-freeze in the pressure washer or flush it?

Where opinions may vary is what to do afterwards. Whether to leave the winterizing solutions inside the water pumpOr, on the other hand, to flush it out once you’ve displaced the regular water and coated the internal surfaces. It’s your choice.

The RV antifreeze won’t freeze, but at most might turn slushy at the coldest temperatures. You should be covered up to -50F which is good enough for just about anyone. If your sole concern is damage from frozen (expanded) water, I’d empty the DIY pump saver out. Nonetheless, if you want the corrosion protection and lubrication just as much as the anti-freeze protection, I’d leave it in.

You’re done!

Meme - Congrats on a job well done! You rock!

Now you know a unique way to winterize a pressure washer!

Wipe the pressure washer off and put it away in a nice cozy location for hibernation. Once you’re ready to use it again, no preparation is needed. Just hook it up and release the power of H2O!

Since it’s biodegradable and stainless, just water it away on your lawn. And if you end up using it sooner than expected, the pump’s internals will appreciate the lubrication. Regardless, given that the winterizing solution is cheap, you won’t feel like you’ve thrown money away.

Anyway, I hope this was helpful. If you found this interesting, check out the what other projects I’ve been up to. Here are a few you might find interesting:

Got any tips, suggestions or questions? Leave a comment below.