DIY RV Winterizing

Taking your RV to a dealer or repair garage can be inconvenient and expensive. Between dropping off your RV and picking it up combined with spendy shop rates, most folks find it easier and less costly to do it themselves. If you have never winterized your RV worry not kind and noble reader, for in this article we walk you through the materials needed and the steps required to help you understand RV winterizing basics.

Why Do I Need To Winterize?

frozen pex pipe with split

That is a good question to get us started. You may not have to if you live in an area where the temps stay above freezing. Alternatively, you may be able to move seasonally to warmer temperatures. In these cases winterizing isn't necessary. If, however, you live in areas where freezing temps are typical in the winter months and you are storing your RV, you will want to winterize it.

Right. But why?

In short, water expands when it freezes. In doing so, rupturing of water pipes and fittings are a common result. Not only can this cause significant water damage to your RV when it thaws, but you also take the chance of the pipe bursting in an area less than convenient to repair. To avoid these highly frustrating situations, all one needs to do is make sure there is no water in the system to freeze. How does one do that you may ask?

Methods For RV Winterizing

Understanding the end goal is to remove water from the RV, there are a few methods which can be used. Some RV owners prefer to use air pressure to blow the water out of the water lines and then just pour antifreeze into the P-Traps. Others prefer to flush the entire system with antifreeze thereby making sure all water has been replaced. Both of these methods have been proven to work effectively, so it is really up to the RV owner on preference. There is one commonality between the two though, and that is always to use antifreeze formulated for RV and Marine use. Do not use vehicle antifreeze for RV winterizing.

Air Pressure

Using this method can be cheaper so long as you have an air compressor to force air into the water system. You connect your air hose to the city water connect using an adapter. After that, you start the compressor an then just go through your RV opening up the faucets until all of the water is blown out. In the long run, you will use less antifreeze year over year, so in time it pays off. You only need enough antifreeze to pour into the drains versus filling the entire water system using this method. You can find kits on Amazon for this technique to help make the process simple.

A word of caution when using the air pressure method. It is suggested you have a pressure regulator on your compressor so as not to over pressurize the water system and blow fittings apart. 

Antifreeze Flush

Another common RV winterizing method involves pumping antifreeze through the entire water system using the onboard water pump. This technique costs a little more in antifreeze but also ensures there is no water left in the system when done correctly. You can also forgo the need for the air compressor and regulator.

Holding Tank Method


water bottle funnel filling rv holding tank

Within this method, there are two ways to go about it. Some folks pour the antifreeze into the fresh water tank after they have drained all of the water out of it. The next step is to turn on the pump and run the toilet and faucets until nothing but antifreeze appears. As you are running antifreeze into the drains, there is no need to add anything else to the drains and holding tanks. Unless you want to be extra safe of course.

There are a couple of reasons some RV owners aren't fond of using the holding tank. One is the fact that getting the antifreeze into the holding tank can be a challenge. There are pumps or funnels available though. We have even seen folks use a water bottle with a hole cut in it for a funnel. The other reason though, is people can taste antifreeze in the water even after they have flushed the system out in the spring. The theory is the plastic of the holding tank absorbs some of the antifreeze over time. There is a way to avoid this though.

Holding Tank Bypass Method

hose in rv antifreeze bottle

A lot of newer RVs have a holding tank bypass system built in. The bypass allows you to shut off the flow of water from the fresh water tank and redirect it to a third hose. The third hose is placed in the bottle of antifreeze and the pump pushes it through the water system. If your RV doesn't have this, there are kits available on Amazon you can install. The holding tank bypass method is the one we use and walk you through in the rest of the article.

Drain The Water System

rv low point drains draining water

The first step is to drain the entire water system including holding tanks, fresh water tank, and the water heater. The way of doing this will vary based on your RV. Many new RVs have "low point" drains which can be used to drain the majority of the water out of the lines and fresh water tank. Some models have a valve on the fresh water tank itself which lets you drain the tank. After that, it is onto the water heater.

Drain The Water Heater

RV Water Heater

It is imperative to drain the water heater as part of your RV winterizing process. It is very messy and expensive should the water in the heater freeze and expand. You take the chance of having fittings and pipes burst as well as damage to the water heater itself. The process of draining the tank is a simple one.

rv water heater plug

Once you pull the panel off, you will find a drain plug towards the bottom of the tank. Using a wrench or socket remove the plug and allow all of the water to drain from the tank. If your water heater has a steel tank, your plug will also have an anode rod attached to it. This is a great time to inspect the rod to see if you will need a new one for next year. Some folks will screw the entire assembly back into the tank while others use a separate plug altogether.

Bypassing The Water Heater

Your next step is to bypass the water heater. Most RVs and coaches can bypass the water heater using valves. If yours does not have this functionality, then the air pressure method may be better suited for your situation.

Different RVs have these valves in different locations. Some have them in a storage bin while others, such as ours, have the valves on the back of the water heater. We found ours by removing an internal panel under the oven. The panel was held on by four screws and was easy to remove.

rv water heater valves

As with all water heaters, there is a cold water "in" pipe and a hot water "out" pipe. Not all of them use nice color-coded Pex pipe like ours, but typically the cold water comes in the bottom, and the hot water comes out of the top. Newer RVs may have a one valve bypass, but most have a three valve set-up. For this set-up, turn the valves for the cold water in and hot water out off, and then turn the bypass valve on. You have just bypassed your water heater. Nice!   

Antifreeze Flush

Next, verify that all of your low point drains are closed from the draining step. Otherwise, you will blow your antifreeze out of them when you turn your pump on. With this done, find where your water pump bypass valves are. These again will be in various location based on your RV and where your water pump is located. Ours was in a "secret squirrel" hiding place under the bed. 

Pump Bypass Valves

Once you find your valves, you want to turn the valve off leading from the fresh water tank to the pump and open the valve going to the bypass tube. Changing the valves forces the pump to draw from the bypass tube versus the fresh water tank. Now you are ready for the antifreeze.

For our little 24ft class C, two gallons of antifreeze gets the job done. A larger coach would use more so plan accordingly. Anything you don't use you can save for the following year. Place the tube into your antifreeze bottle, and you are ready for battle. All of the hard work is done and your RV winterizing is almost complete!

RV pump switch

Find the switch on your panel and turn your water pump on. Your pump should now be sucking the antifreeze out of the bottle into your system. You now want to go to every faucet in and out of the coach turning on the cold and hot water. Some RVs have external showers and outdoor kitchen to consider.

Running antifreeze through rv faucet

Start with just the cold water until it runs pink and then do the same with the hot water. You want to make sure that both hot and cold pipes are full of the antifreeze. You will also want to flush the toilet continuously to make sure all of the water is out of there as well. The beautiful part about this is that by running the faucets, shower and toilet you not only verify the water is out of the lines, you are also running antifreeze into the P-Traps and holding tanks.

That is all there is to it! Once you have winterized your RV a few times, you will find it can be done in under an hour or so. Come spring you can flush all of the antifreeze out and sanitize your system to get it ready for use!

In Summary

This post was designed to offer a high-level view of why RV winterizing is important and how to go about it. As previously mentioned, different RV manufacturers construct their RVs differently so the locations and methods of some things may differ accordingly. Additionally, the age of the RV may also create situations not spoke to in this post. All of that said, we hope this post saves you some money and offered some insight into RV winterizing basics!

Find all of the products to help you winterize your RV and more in the maintence section of our webstore here ->

Are you looking for a new RV? Check out our free Essential RV Buying Tips Guide here -> Essential RV Buying Tips Guide


Thank you for reading...

rv park empty with snow

Last update on 2022-06-27 / Affiliate links / Images from Amazon Product Advertising API

1 thought on “RV Winterizing Basics For Newbies”

  1. Great article, thank you. Most RV dealerships want you to come back so they can charge you for what you can do yourself. Please continue to post these very helpful and informative articles.


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