When and How to Winterize a Pressure Washer

Title image for how to winterize a pressure washer

When and How to Winterize a Pressure Washer

If summer is ending, it’s time to winterize your pressure washer. Freezing temperatures can do a number on your pressure washer if you don’t prepare it. You could find your pressure washer is hard to start in the spring—or doesn’t start at all.

Winterizing your pressure washer sounds like a hassle, and it does involve a few steps, but this guide will make it easier on you. We’ve created the most convenient guide by combining some steps to save you time. Storage is just as essential as winterization, so we’ll share storage tips that will keep your pressure washer in even better condition. We’ll also explain why you’re winterizing your pressure washer, so you understand what problems you’re avoiding.

Why Is This Process Important? 

Many people don’t go to the trouble of winterizing their pressure washer. If it’s going to freeze outside or if they aren’t going to use their pressure washer for a month, they just put it away in the garage. Unfortunately, this can do serious damage to your pressure washer, potentially breaking it entirely. 

In fact, we suspect that many people who complain that their mid-range pressure washer didn’t make it past a year allowed the pressure washer to freeze up over the winter. Thus, they broke it, to no fault of the manufacturer. 

So, it’s important to know what problems you might cause if you don’t winterize your pressure washer. That way, you’ll understand the importance of winterizing your pressure washer. Plus, you’ll know which problems you can blame the manufacturer for (and which you can’t expect a refund or warranty coverage for.) 

Here’s what can happen if you don’t winterize your pressure washer: 

  • Broken seals, tank and hose: The most serious risk of not winterizing your pressure washer is that the water you leave in the machine will freeze. When water turns to ice, it expands. The pressure of this expansion can burst seals, break the tank, and disconnect the hose. Any part of the pressure washer that had a bit of residual water could break from freezing. 
  • Poor function from mineral deposits: If you leave water in your pressure washer tank, the natural mineral content will collect on the tank, hose, and seals. These calcium deposits can interfere with the proper function of your pressure washer. Calcification will happen faster the harder your water is. You can wash the deposits out with vinegar, but that’s more of a hassle than just winterizing your pressure washer in the first place. 
  • Broken engine from stale gas: Gasoline isn’t stable. It slowly loses it’s combustible power, starting about 30 days after you pour it into your gas pressure washer because that exposes it to oxygen. 

If you allow your gas to go stale in the pressure washer, you may find it’s hard to start when you next try to use it, which damages the engine. Or, your pressure washer could refuse to start at all. Sometimes draining the fuel and adding in fresh gasoline doesn’t solve the problem, the engine has already been damaged. The simple solution is to add a fuel stabilizer that prevents gasoline from degrading as quickly.

  • Loss of warranty: If you don’t winterize your pressure washer according to the manufacturer’s instructions you may void their warranty. If something goes wrong, even if it couldn’t have been caused by freezing or stale gas, the manufacturer has a right to deny your requests for repairs and replacement.  

Ultimately, you made an investment when you purchased your pressure washer. It’s wise to protect that investment by winterizing the machine properly. Otherwise, you’ll spend more money and time trying to troubleshoot, repair or replace it. 

What is a Pressure Washer Pump Saver? 

Pump saver is a liquid chemical solution that keeps water out of your pump and prevents any residual water from freezing. It is actually just simple antifreeze. So, you can buy any antifreeze to put in your pressure washer, not just specifically marketed “pump saver.” Depending on where you’re shopping, that can save you some money. 

It’s important to put pump saver into your pressure washer instead of just leaving it dry. Pump saver protects the seals on your pressure washer from drying out. Dry seals can come loose or break, which can ruin your pressure washer and cause leaks. Or, it may just reduce the amount of pressure it can output, which means it may not be able to clean the surfaces it could clean before. 

How does antifreeze work? Not all liquids become a solid (or freeze) at the same temperature water does. Antifreeze is just a liquid that freezes at a much lower temperature than water. These liquids include methanol, ethylene glycol, propylene glycol and more. Sometimes pump saver is made of a mixture between water and one of these chemicals. Regardless, antifreeze can be toxic, so it’s important to store it carefully. We talk more about the proper storage of your pump saver below.

How to Winterize an Electric Pressure Washer? 

Electric pressure washers are easier to winterize than gas pressure washers. You only have to protect the pump and not the fuel tank. Just follow these simple steps:

  1. Get a bucket of clean water and place the pressure washer’s injection tube into the bucket. If your model does not have an injection tube, where you add detergent, then simply pour the water into the detergent inlet. 
  2. Run the pressure washer for two minutes, at low pressure. By doing so, you rinse out the pump and lines, removing the detergent. 
  3. Turn off your garden hose. Disconnect your pressure washer from your hose. Spray the lance to remove any pressure.
  4. Next, remove the lance, hose and any dry attachments that can be removed. 
  5. Turn the pressure washer back on and shake it gently, trying to remove any excess water. Only do so if your pressure washer is small enough that it’s safe to lift. 
  6. Then turn the pressure washer off and pull the recoil handle to remove more water. 
  7. Through the garden hose inlet, pour in pump saver. 

Now your electric pressure washer is winterized and ready to be stored. Be sure to store it in a safe location where pets and children can’t access it. For more tips on how to store it, read the storage section below.  

How to Winterize a Gas Pressure Washer? 

In order to winterize a gas pressure washer, you need to follow a few more steps than you would with an electric pressure washer because you need to secure the fuel. Here’s how you can winterize your gas pressure washer:

  1. Pour gas stabilizer into the fuel tank to protect your fuel and engine components over the winter. The stabilizer does need to be circulated through the engine, by running the pressure washer for a bit. But don’t do it just yet. 
  2. You also need to remove the detergent from the pump, which you accomplish by running clean water through the detergent tank. You can add clean water to the tank by pouring it in. Or, if your gas pressure water has an inlet hose, put the hose in a bucket of clean water. 
  3. Now run the pressure washer for two minutes, on low pressure. You’ll be circulating the gas stabilizer and cleaning out the detergent at the same time. Most guides have you do these steps separately, but it’s just a waste of time. 
  4. Turn off your pressure washer and disconnect it from your hose. 
  5. Spray the handle to release any pressure. 
  6. Remove the hose, lance and any other dry attachments. 
  7. Pour pump saver into the pressure washer through the hose inlet.  

Now your gas pressure washer is winterized and ready to be stored. 

You’ll notice we didn’t tell you to shake your gas pressure washer to help remove extra water. Gas pressure washers are larger and heavier than electric. Shaking isn’t going to do much for you except potentially pull your back out. 

When Should You Prepare Your Pressure Washer For Winter? 

It’s not always obvious when you should winterize your pressure washer. If you live in an area with long winters, we suggest you winterize your pressure washer a week or so before your first frost date. You can find your first frost date for the current year at the Farmer’s Almanac. There is a thirty percent chance you get your first overnight freeze before the frost date, which is why we suggest you do it beforehand. That way, you don’t run any risk of letting your pressure washer freeze up. 

If you live in California or other states where freezing is rare, we recommend you winterize your pressure washer once temperatures are in the single digits. Once you have these cold temperatures, you could get a surprise freeze. You likely won’t have time to winterize your pressure washer when preparing for a sudden freeze. 

Plus, no matter your climate, you should winterize your gas pressure washer if you don’t intend to use it in the next 30 days. By doing so, you protect the stability of your fuel and the pressure washer’s engine and other components from fuel-related problems. 

Technically, winterizing your electric pressure washer is also wise if you won’t use it for 30 days. Sitting water can cause mineral deposits and other problems with your electric pressure washer. Plus, remember that if you remove water from your pressure washer, you need to add in pump saver to keep the seals from drying and suffering damage. It isn’t just about freezing weather. 

How to Properly Store Your Antifreeze and Winterized Pressure Washer

How to winterize a pressure washer with antifreeze isn’t the only thing you need to know. Once you have antifreeze on your property, you need to be careful about how you store it. 

Some antifreeze, the kind made from ethylene glycol, is poisonous to people and pets. Even small amounts can cause kidney failure and death. Even though ingesting pump saver gives you string symptoms, they are easy for doctors to confuse with other illnesses. Plus, antifreeze tastes sweet, which can attract pets and children to the substance. So, it’s important to store antifreeze out of reach of children and pets, ideally in a cabinet or closed storage bin. 

If you have particular curious pets or young children it may be worth your while to buy non-toxic antifreeze, made from propylene glycol. You could also buy from an antifreeze company that adds a bitter taste to their product to discourage pets and kids from eating it. 


We suggest you use a funnel and safety gloves to pour the tank saver into your pressure washer. After you’ve used antifreeze it is important to clean up any spills. Keep the antifreeze in its original storage and never re-use its container for another purpose.

Remember, once your pressure washer has antifreeze it in, it also needs to be stored safely away from pets and children. We suggest you place it in a cover and then store it in a locked shed or garage. Plus, take care if you notice any leaks around the pressure washer, as it could be the antifreeze. Or, if you have a gas-powered pressure washer, the leak could be gasoline. 

Starting Your Pressure Washer in Spring

If you’ve properly winterized your pressure washer, you’ll need to start it back up again in the spring carefully. Instead of using it immediately, you’ll need to run it for a few minutes to allow the pump saver to drain. 

Again, this is a toxic substance. Take care to drain the pressure washer (by running it on a low-pressure setting) into a container that you can then take to a recycling plant. Or, follow your city’s instructions and the manufacturer’s instructions on how to safely dispose of your particular brand of antifreeze safely. It is usually not safe to just pour the antifreeze down the drain or onto the ground. 

Want to Learn More About Pressure Washers? 

Now that you know how to winterize a pressure washer, you might be looking for some last-minute projects to try out before you put it away. Or, maybe you want to learn more about pressure washers in general? Check out our blog section for more information about pressure washers, from other pressure washer enthusiasts.