If your RV experiences freezing temperatures, you must learn how to winterize your RV. A big part of that process is using RV antifreeze, and there are many questions about what to choose and how to use it correctly.
For starters, let’s give you a brief overview of the RV winterization process:
Now that you’re familiar, here’s everything you need to know about RV antifreeze.
What is RV Antifreeze?
Some RV owners call it “the pink stuff,” but antifreeze can be many colors. More importantly, it’s a liquid with a much lower freezing point than water. Replacing the water in your plumbing lines with RV antifreeze protects it from freezing, expanding, and potentially bursting.
Most RV antifreeze solutions are either ethanol or propylene glycol-based. Both lower the solution’s freezing point, but propylene glycol also raises the solution’s boiling point. The types of RV antifreeze used at most Camping World Service Centers have a freezing point of -50℉.
Is RV Antifreeze Toxic?
It depends on the antifreeze you’ve chosen. Propylene glycol RV antifreeze is a non-toxic solution safe for RV plumbing systems and holding tanks. That said, care must be taken to completely flush antifreeze and sanitize your RV’s fresh water system when de-winterizing your RV.
Here’s a quick video explaining how to sanitize your RV’s fresh water tank:
You should never dump RV antifreeze on the ground when you flush your system. It should be disposed of properly (more on that below), as it can harm plants and animals if consumed.
Is RV Antifreeze Toxic to Animals?
When using antifreeze or other RV chemicals, your first step should be reading the warning label. While it’s non-toxic for your RV’s pipes, faucets, and fixtures, it can be toxic to humans and animals if consumed.
This is especially true for cats, which can experience adverse effects if exposed to RV antifreeze in small quantities. Dogs are less sensitive but can still suffer negative effects if large quantities are consumed.
Fortunately, you should be using antifreeze when prepping your RV for winter storage and not handling it again until it’s time to de-winterize it. So keep your pets in the house during these processes, and you’ll be fine.
If your animals accidentally consume RV antifreeze, please seek immediate veterinary attention.
How Much RV Antifreeze Do I Need?
The recommended amount of RV antifreeze for your motorhome or towable depends on the size. You’ll notice in the article and video on RV winterization we recommend bypassing your water heater. This is mainly because you’ll need a lot more antifreeze if you don’t.
Most RVs will use roughly 2-4 gallons of RV antifreeze. This includes what goes down the sinks to ensure any remaining water in the P-traps doesn’t freeze.
Component Definition: P-traps are the U-shaped sections of pipe beneath your sinks that hold water to prevent odors from your grey water holding tank from entering the cabin.
How Much RV Antifreeze to Put in Holding Tanks
Part of winterizing your RV is pouring antifreeze down the sinks to fill the P-traps. Naturally, this will result in some antifreeze traveling through your plumbing and into the grey water tank.
Pouring 1-2 cups down each sink is recommended. Additionally, you can pour another 2-4 quarts into your RV toilet and then flush the toilet to leave a small amount in your black tank. This can prevent the freezing of residual waste and save you from having to unclog your black tank in the spring.
Adding antifreeze to your black water tank isn’t required, but it can prevent leftover tank waste from freezing and causing tank damage. Even if you frequently use your black tank flush to clean your tank as thoroughly as possible, RV holding tanks almost always hold residual waste.
How to Get Antifreeze Into RV Lines
When your RV is winterized at a Camping World Service Center, your trained technician will utilize the T-valve before your water pump and connect a hose to pull antifreeze from the bottle into your RV’s plumbing lines.
You can do this by adding a water pump bypass or disconnecting the line to the pump and connecting a three-foot hose. You’ll need the proper fitting to connect the hose to the pump, and then you can insert the other end of the hose into your bottle of antifreeze to pump it through the system. Before pumping through the system, ensure your water heater is effectively bypassed.
We don’t recommend adding antifreeze to your freshwater tank because it can require up to 10 gallons before the pump can pick it up, especially if your tank has a side pickup. The antifreeze will need to completely cover the pickup opening to keep the pump from sucking air. You’ll also need to spend a lot of time flushing the fresh tank when de-winterizing your RV to get it to stop foaming at the faucets.
How to Flush Antifreeze Out of an RV
Once you’ve winterized your RV, you’ll have antifreeze throughout your plumbing lines, in the P-traps, and a small amount in each of your holding tanks. Before you can safely use your RV’s water system for showering, washing dishes, and drinking, you’ll need to flush all traces of antifreeze.
Here are the quick steps to flushing RV antifreeze:
- Position your RV near a sewer connection and connect your sewer hose.
- Connect a potable water hose to your fresh water inlet and fill your fresh water tank.
- Turn on your water pump to pressurize the system.
- Open all sink and shower fixtures to run water through your system and into the grey water tank. You can also depress the pedal on your RV toilet to run water through your toilet’s plumbing and into the black tank.
- Open all outside showers and low-point drains to let them run until clear water comes out.
- When your grey tank reaches two-thirds capacity, turn off all fixtures and shut down the water pump.
- Go outside and open the tank valves to drain your holding tanks (black, then grey).
- Repeat this process at least 2-3 times until the water coming out of your fixtures is clear and completely free of any colored residue that matches the original color of your antifreeze.
Additionally, go back to the video above to ensure you sanitize your fresh water system thoroughly after flushing the antifreeze.
How to Dispose of RV Antifreeze
Sure, RV antifreeze isn’t toxic for your RV’s plumbing, but you can’t just dump it on the ground when flushing your system in the spring. Even antifreeze products labeled ‘biodegradable’ should be properly drained into a dump station, septic tank, or residential sewer clean-out.
If you cannot move your RV to dispose of antifreeze in one of these locations, you may also empty it into a portable RV waste tank. You’ll then need to transport that tank to one of the aforementioned locations to dispose of it properly.
Does RV Antifreeze Evaporate?
Yes, but RV antifreeze evaporates much more slowly than water. This is one reason antifreeze effectively protects your RV’s plumbing when you aren’t using it for an extended period.
Under the right conditions, however, the antifreeze will evaporate. The first condition is if the temperature of the antifreeze rises above 223℉ – not impossible, but highly unlikely during winter RV storage.
The second condition is if antifreeze is mixed with water to achieve a 50/50 ratio. This is not recommended for winterizing your RV, but the effect will be a diluted solution that evaporates slower than water but more quickly than an undiluted solution.
Does RV Antifreeze Go Bad?
Most RV antifreeze lasts anywhere from 1 to 4 years once opened. Depending on your product choice, your bottle(s) may or may not be labeled with an expiration date. If yours aren’t, a simple test is to shake the bottle and observe the liquid inside. If bubbles appear, your antifreeze has expired.
Here are some tips to maximize your RV antifreeze’s shelf life:
- Only open bottles when you’re ready to use them for winterization.
- Store RV antifreeze in a cool, dry, shaded location.
- Avoid leaving it outside in direct sunlight, especially when temperatures exceed 50℉.
Can You Use RV Antifreeze in a Car or Truck?
No, RV antifreeze and the recommended antifreeze for your automotive are not interchangeable. You shouldn’t use RV antifreeze in an automotive, and you can’t use the same antifreeze you use for your automotive to winterize your RV.
This is because RV antifreeze is designed for your plumbing, while automotive antifreeze is designed for the engine. Automotives usually require ethanol-based antifreeze (or an ethylene glycol base), which is toxic and should never be used in your RV’s freshwater system.
So if you have a motorhome, you’ll need separate antifreeze solutions for your engine and your RV’s plumbing. The bottom line – find an antifreeze recommended by your automotive’s manufacturer and use a less toxic propylene glycol antifreeze to keep your RV’s plumbing lines safe during the winter.
Where to Buy RV Antifreeze
Find your nearest Camping World location to pick up RV antifreeze before it’s time to winterize again. Our recommended product is the Champion RV & Marine Antifreeze, but if you’ve never winterized your RV before, our RV winterization bundle gives you everything you need to get the job done.
Check out Camping World’s selection of RV antifreeze products.
Knowing where to find and how to use RV antifreeze is key to keeping your water lines healthy when temperatures dip below freezing. Hopefully, these answers will help with your future winterization efforts, but please don’t hesitate to reach out if you have others.
Do you have other questions about RV antifreeze or how to use it? Share them in the comments below!
Tucker Ballister is our Technical Content Writer. He’s a lover of the open road and the proud owner of a 2021 Sunlite Classic travel trailer (his 3rd RV to date). Check out more of his RV adventures, gear reviews, and outdoor advice at thebackpackguide.com.
