RV Antifreeze: Protect Your RV Plumbing From Bursting

It’s that time of year… temperatures have dropped and many people have their RVs stored until spring. But are they adequately protected? That’s where RV antifreeze comes in!

Lots of people blow out their plumbing lines with an air compressor (in fact, we’ve done it ourselves), but that doesn’t mean you don’t need antifreeze. There are a couple of different ways to tackle RV winterization, and both work well. But no matter how you choose to prepare your rig for cold temps, you still need some RV antifreeze.

What is RV Antifreeze?

Maybe the first thing we should mention is what RV antifreeze is NOT. RV antifreeze is not the same thing as automotive antifreeze. The two are completely different products.

RV antifreeze (“the pink stuff”) is a product that is designed for the purpose of protecting the various components of an RV’s plumbing system from expanding in the cold and bursting. It works by lowering the temperature at which water freezes (known as the freeze point). Some types of RV antifreeze also serve as a lubricant to protect seals inside RV toilets and faucets from cracking in the cold and from lack of use.

All RV antifreeze is intended to protect your RV’s plumbing system, but all RV antifreeze is not the same. Some is ethanol-based, some is propylene glycol-based, and, less commonly, some RV antifreeze is a blend of both ethanol and propylene glycol.

The safest option is propylene glycol-based antifreeze. Not only is it safe for all aspects of an RV plumbing system, but unlike ethanol-based antifreeze, propylene glycol-based antifreeze is non-flammable.

Propylene glycol also acts as a lubricant for faucets and toilet seals and leaves behind less of a taste in your fresh water plumbing than ethanol-based antifreeze. Propylene glycol antifreeze is also used as marine antifreeze for the winterization of the water systems in boats as well.

You can find this type of antifreeze in grades that are guaranteed to offer burst protection down to -50°F, and some even provides coverage down to -100°F!

What’s Different About RV Antifreeze?

Perhaps the most important difference between RV antifreeze and other antifreeze is that RV antifreeze is non-toxic to humans as long as it is used in its intended manner (in other words, don’t drink it!).

HOWEVER, RV antifreeze has a sweet scent and taste that is alluring to animals, and it can be toxic, especially to cats, even in small amounts.

It can be toxic to dogs in larger amounts, so do bear all of this in mind when using, spilling, and storing your RV antifreeze. For much more on the toxicity issue, please see our post Is RV Antifreeze Toxic?

How Much Do I Need to Use?

The answer to this question depends on how you intend to winterize your RV. If you’re using an air compressor to blow out your RV water lines, you’ll need to use very little RV antifreeze, but you will need to use some. Even when you blow out all of the water lines, you still need to put some antifreeze down each drain to protect them, as well as in your toilet bowl(s) to help protect the seals.

If you intend to use RV antifreeze to protect your entire RV plumbing system, you’ll need significantly more antifreeze, and you’ll need to run the antifreeze through the entire system. The one exception to this is the water heater.

For standard RV water heaters with a tank, you’ll want to bypass the heater before running any antifreeze through the system. Then, just open the pressure relief valve and remove the drain plug or anode rod to let the tank drain completely. The water left in the bottom of the tank won’t do any damage, even if it freezes. And, this way, you don’t need to buy enough antifreeze to completely fill the water heater tank (anywhere from 6 to 12 gallons!).

NOTE: For on-demand water heaters, be sure to follow the manufacturer’s instructions for winterizing. Some can just be drained, others may require you to protect them with antifreeze.

Our water heater flush and inspection video may be helpful to you as you seek to drain your water heater ahead of cold weather.

Once you’ve dealt with the water heater, you’ll want to be sure to run antifreeze through all of your RV’s fresh water plumbing. That means you’ll need to run antifreeze solution into the washer (or washer prep) lines, the ice maker or through-the-door water dispenser, and any dedicated filtered water spigots. (To do this you’ll want to bypass the filter and remove it, and then drain it to prepare it for use next season.)

For more detail about the amount of RV antifreeze you’ll need to properly winterize your camper, check out our article: How Much RV Antifreeze Do I Need To Winterize My RV Plumbing?

When Should I Use It?

Any time you anticipate being in an area where ambient temperatures are likely to stay at freezing (32°F / 0°C) or below, you need to completely drain your RV’s plumbing system by blowing it out with air pressure and/or by using RV antifreeze.

Note that blowing out the lines is easier if you only intend to store your rig in cold temperatures for short periods and you want to be able to put the RV back into service quickly. However, it’s important to know that blowing out the lines may not protect all of the components in your plumbing system if temps drop significantly below freezing, especially for significant lengths of time: using RV antifreeze is the better choice in these conditions because it offers more complete protection.

Water doesn’t take long to freeze (for more details, please see our post: “How Long Does It Take for Water to Freeze in RV Pipes?“), so if you anticipate freezing or sub-freezing temperatures for any length of time, be sure to winterize properly to prevent you from needing to replace plumbing lines and other components.

Where Should I NOT Put RV Antifreeze?

You should not put antifreeze in your RV’s water heater unless your brand/make/model of water heater (typically on-demand style) recommends it in the owner’s manual.

And while it’s non-toxic and generally harmless, try to avoid putting RV antifreeze in your RV fresh water tank. That will keep you from having to rinse the tank out multiple times to remove the smell and taste when you’re preparing for the upcoming camping season.

Putting RV antifreeze in your fresh water tank MAY be unavoidable because you need to run the antifreeze through the entire plumbing system and doing so may be the easiest way to accomplish that. Just be sure to thoroughly rinse the scent and taste of the antifreeze away, come spring.

While we’re on the subject, in case it’s helpful, here’s our post on sanitizing an RV fresh water tank.

What’s Your Preferred Method of Winterizing Your RV’s Plumbing System?

Out of curiosity, do you prefer to blow out your water lines using an air compressor and then use some RV antifreeze to complete the winterization?

Or is it your preference to complete your entire winterization using several gallons of RV antifreeze?

Drop us a comment below and let us know!

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