Learning how to winterize a washing machine in an rv is one of those chores you really can't afford to skip if you live or travel in a climate where temperatures dip below freezing. If you've ever dealt with a burst pipe or a cracked water pump in your rig, you know exactly how expensive and annoying those repairs can be. Washing machines are particularly vulnerable because they hold onto little pockets of water in places you can't see, like the pump, the internal valves, and the drain hose.
When that water turns to ice, it expands, and since plastic and metal don't like to stretch, something has to give. Usually, it's a vital component of your appliance. Taking an hour or so to properly prep your machine for the winter can save you hundreds of dollars and a whole lot of frustration when you're ready to hit the road again in the spring.
Why you can't just drain the water
A common mistake many RVers make is thinking that simply running a spin cycle or draining the hoses is enough. Unfortunately, modern RV washing machines—whether you have a stackable unit or a combo ventless model—are designed with traps and pumps that naturally retain water to keep seals moist and prevent sewer gases from coming up through the lines.
Gravity won't do the work for you here. You have to actively push that water out or replace it with something that won't freeze. That's where the "pink stuff"—RV antifreeze—comes into play. Unlike the green stuff you put in your car, RV antifreeze is non-toxic and safe for plumbing systems, which is exactly what you need for an appliance that handles your clothes.
Getting your supplies together
Before you dive in, grab everything you'll need so you aren't running back and forth to the storage shed. You're going to need a few gallons of RV antifreeze (propylene glycol). Don't skimp here; it's better to have an extra bottle than to run out halfway through the process.
You might also need a small bucket, some towels to catch drips, and potentially a screwdriver or pliers if your hose connections are on extra tight. If your RV has a "winterization kit" or a bypass valve for the water pump, make sure you know where that is, as it makes the whole process much smoother.
The antifreeze method step-by-step
This is generally considered the most reliable way to handle the job. The goal is to get that pink antifreeze through the hot and cold intake valves, into the drum, through the pump, and out the drain hose.
First, make sure the machine is completely empty. No stray socks or lint left behind. Turn off the water supply to the machine. If you have a way to pump antifreeze directly through your RV's plumbing system using your onboard water pump, that's the easiest route.
Set your washing machine to a "Warm/Warm" fill setting. This ensures that both the hot and cold water solenoid valves open up. Start the cycle and let it run until you see the pink antifreeze flowing into the drum. This usually takes a minute or two. You want to see a good amount of that color to be sure the water in the lines has been fully replaced.
Once you see the pink stuff, turn the machine off or advance the cycle to "Spin/Drain." As the machine drains, the antifreeze will move through the internal pump and out the discharge hose. You've now protected the most sensitive parts of the machine.
Using the air blowout method
Some people prefer not to use antifreeze because they don't like the smell or the cleanup involved in the spring. If you have a decent air compressor, you can "blow out" the lines. However, be careful with this. You need to set your compressor to a low PSI—usually around 30 to 40—so you don't blow out the seals in your machine or your RV's plumbing.
To do this, you'll attach the air compressor to the city water inlet and open the laundry valves. Just like the antifreeze method, you'll run a fill cycle on warm to let the air push the water out of the lines and into the machine.
The tricky part with air is the pump. Even if the lines are clear, the pump and the drain trap will still have water in them. To be safe, I usually recommend a hybrid approach: blow out the lines with air, but still pour about half a gallon of RV antifreeze directly into the drum and run a quick drain cycle to protect the pump. It's the best of both worlds.
Don't forget the low point drains
While you're focused on the machine itself, don't forget the plumbing leading to the machine. If your washer is at the back of the RV, those lines can be quite long. After you've run the antifreeze through the machine, it's a good idea to open your RV's low point drains for a second to make sure any remaining water in the supply lines has been displaced by the pink stuff.
I've seen plenty of people winterize their washer perfectly, only to have the Pex pipe behind the wall burst because they forgot the supply line itself. It's a "whole system" mindset that keeps things safe.
Cleaning the filter and seals
Since you're already messing with the machine, this is a great time for a little bit of maintenance. Most RV washing machines have a lint or debris filter located at the bottom behind a small plastic door.
Unscrew that filter (have a towel ready, because some water will leak out) and clean out any coins, lint, or hair that's accumulated. If this filter is clogged and then freezes, it can crack the housing, which is a nightmare to replace. Once it's clean, screw it back in tightly. Also, wipe down the rubber door seal with a bit of vinegar or a mild cleaner to prevent mold from growing while the machine sits idle for the winter.
Leaving the door ajar
This might sound like a small thing, but it's actually pretty important. After you've finished how to winterize a washing machine in an rv, leave the door cracked open just an inch or so.
RVs can get humid, and if you seal up a damp washing machine for three or four months, you're going to walk into a wall of mildew smell when you open it in the spring. Leaving the door open allows for airflow and ensures the interior stays dry. If you're worried about the door swinging around while the RV is in storage or being moved, you can use a bit of painter's tape to hold it in a slightly open position.
What to do when spring arrives
When the birds start chirping and you're ready to de-winterize, the process is pretty straightforward. You'll want to hook up your fresh water supply and flush your entire RV system to get rid of the antifreeze.
For the washing machine specifically, run a complete cycle (without clothes!) on the longest, hottest setting available. Use a little bit of laundry detergent or a specialized washing machine cleaner. This will flush the antifreeze out of the lines, the pump, and the drum. I usually run two cycles just to be extra sure my first load of laundry doesn't end up smelling like a chemical factory.
Final thoughts on cold weather prep
It's easy to get overwhelmed with the list of things you have to do to get an RV ready for winter. From the holding tanks to the engine, there's a lot to remember. However, your washing machine is one of the most delicate (and expensive) systems on board.
By taking the time to follow these steps, you're essentially buying insurance against a very wet and very expensive disaster. It doesn't take much—just some pink antifreeze, a little bit of patience, and a clear understanding of your machine's cycles. Once you've done it a couple of times, it'll just become another part of your seasonal routine, giving you peace of mind while you wait for the next camping season to begin.