Preparing your rig for the off-season involves more than just draining the fresh water tank and parking it under a cover. If you enjoy the luxury of on-board laundry, you must pay special attention to the delicate internal components of your appliance.
Learning how to winterize rv washer units is the only way to prevent ice from expanding inside solenoid valves and plastic pump housings. A single night of sub-freezing temperatures can lead to cracked lines and a very expensive repair bill come springtime.
In this guide, I will share the exact steps I use as a technician to ensure your washer survives the harshest winter. We will cover the tools you need, the two primary methods of protection, and the critical safety steps every owner should follow.
Why Learning How to Winterize RV Washer Systems is Non-Negotiable
Most RV components are built to be lightweight, which often means they use high-density plastics and thin copper for internal plumbing. The water inlet valves on a washer-dryer combo are particularly vulnerable to freezing because they hold a small amount of residual water.
When that water turns to ice, it expands with enough force to split the valve body wide open. You won’t notice the damage until you hook up the water in the spring, only to find a flood inside your cabinetry.
Properly winterizing the unit ensures that every drop of water is either replaced by non-toxic antifreeze or blown out with compressed air. This protects the internal pump, the drain lines, and the often-overlooked P-trap hidden behind the machine.
Essential Tools and Supplies for the Job
Before you begin, gather your supplies so you don’t have to stop mid-process with a half-full machine. Having the right gear makes the job faster and ensures you don’t damage any fittings.
- RV Antifreeze: Use only the pink, non-toxic (Propylene Glycol) variety. Never use automotive antifreeze.
- Adjustable Wrench: For loosening hose connections if you need to drain them manually.
- Bucket: To catch any residual water from the supply lines or the pump filter.
- Air Compressor: Only necessary if you prefer the “blow-out” method over the antifreeze method.
- Pressure Regulator: To ensure you don’t exceed 30-40 PSI when using compressed air.
I always recommend keeping a few microfiber towels nearby. Even when you are careful, a small amount of water usually escapes when you disconnect the hot and cold supply hoses.
Detailed Steps on How to Winterize RV Washer Units Using Antifreeze
The antifreeze method is the most reliable way to protect your machine. It ensures that the internal pump and the drain trap are fully protected by a liquid that won’t freeze, even in extreme temperatures.
First, ensure your RV’s water heater is bypassed and the main water system has been drained. Once the main lines are clear, you can focus specifically on the washer unit.
Step 1: Preparing the Supply Lines
Connect your RV’s water pump to a jug of pink antifreeze using a winterizing kit or a siphon hose. Turn on the pump to pressurize the system with the pink fluid.
Set the washer to a “Warm” wash cycle and start the machine. This forces both the hot and cold solenoid valves to open, pulling antifreeze into the internal mixing chamber.
Step 2: Monitoring the Drum
Watch the washer drum closely as it begins to fill. You are looking for the moment the liquid entering the drum turns bright pink.
Once you see the pink antifreeze, let it run for about 30 seconds to ensure the internal hoses are full. Then, advance the cycle or manually switch the machine to the “Spin” or “Drain” setting.
Step 3: Protecting the Pump and Drain
As the machine drains, the pump will push the antifreeze through the discharge hose and into the P-trap. This is a vital step because the trap always holds water to block sewer gases.
Turn the machine off and unplug it from the power source once the pump has finished its cycle. You have now successfully replaced all water with protective fluid.
The Compressed Air Method: A Dry Alternative
Some owners prefer not to use antifreeze inside the machine to avoid the cleanup process in the spring. While effective, this method requires a bit more precision to ensure no water pockets remain.
Start by connecting your air compressor to the city water inlet using a blowout plug. Set your regulator to a maximum of 35 PSI to avoid blowing out the seals in your washer’s valves.
Step 1: Clearing the Inlet Valves
With the air pressure steady, turn the washer on to a “Warm” cycle. You will hear the air hissing through the valves and into the drum.
Continue this until you no longer hear the “gurgling” sound of water being pushed through the lines. This typically takes about two to three minutes of intermittent cycling.
Step 2: Gravity Draining the Pump
Air alone often won’t clear the bottom of the pump housing. Most RV washers have a debris filter or emergency drain hose located at the bottom front of the unit.
Place a shallow pan on the floor and open this filter cap slowly. Allow any trapped water to drain out completely, then securely tighten the cap back into place.
Step 3: Don’t Forget the Trap
Even if you use air for the machine, you must pour a quart of RV antifreeze directly into the washer drum and run a quick drain cycle. This ensures the drainage system and P-trap are protected, as air cannot clear a trap effectively.
Common Pitfalls to Avoid During Winterization
One of the most frequent mistakes I see is forgetting to clear the input screens. These tiny mesh filters sit inside the hose connections and can trap small amounts of water that lead to cracking.
Another error is assuming that “dry” machines don’t need attention. Even if you haven’t used the washer in months, the lines leading to it still contain water that can freeze and burst back toward the main plumbing trunk.
Always double-check your low-point drains. If the washer is located at a higher elevation than the drains, gravity might help you, but it won’t clear the internal loops inside the appliance itself.
Cleaning the Pump Filter: A Pro Tip
Since you are already working on the machine, this is the perfect time for annual maintenance. Most RV washers, like those from Splendide or Whirlpool, have a front-access lint and coin trap.
Unscrew the filter and clear out any lint, hair, or stray debris. A clogged filter can prevent the pump from draining efficiently, which might lead to incomplete winterization and ice damage.
Wipe the rubber door seal with a damp cloth and leave the door slightly ajar. This prevents mold and mildew from growing in the damp, dark environment during the months the RV is in storage.
Maintaining Your RV Washer for Longevity
Consistent care is the key to making your appliances last as long as your rig. Beyond just knowing how to winterize rv washer units, you should inspect the rubber supply hoses every season.
Look for signs of “bubbling” or cracks in the rubber. If your hoses are more than five years old, consider upgrading to stainless steel braided lines, which offer much higher burst protection.
When you pull the RV out of storage, remember to “de-winterize” by running two full cycles with plain water and a cup of vinegar. This flushes out the pink antifreeze and sanitizes the drum for your first load of laundry.
Frequently Asked Questions About How to Winterize RV Washer
Can I use regular automotive antifreeze in my RV washer?
No, you must never use automotive antifreeze. It is highly toxic and can leave dangerous residues in your laundry system. Always use the pink RV/Marine antifreeze specifically designed for potable water systems.
How much antifreeze does an RV washer usually need?
Generally, you will need about one to two gallons to fully winterize a washer. This accounts for the fluid needed to fill the supply lines, the internal mixing valve, the pump, and the drain trap.
Do I need to winterize the washer if I keep a heater running in the RV?
Yes, you should still winterize it. If your power fails or the heater runs out of propane, the temperature inside the rig will drop rapidly. It is much cheaper to winterize than to risk a catastrophic leak.
What if my washer is a stackable unit?
The process is identical for stackable units, though accessing the rear hoses may be more difficult. Ensure you have long enough hoses to reach your antifreeze jugs without having to pull the heavy units out of their enclosure.
How do I know if the antifreeze reached the pump?
You will know the pump is protected when you see pink fluid exiting the external drain vent or when you see it swirling in the bottom of the drum during the drain cycle.
Summary of Key Takeaways
Protecting your RV’s laundry center doesn’t have to be a daunting task. By following the steps outlined above, you can rest easy knowing your appliance is safe from the destructive power of ice.
Remember to always prioritize the antifreeze method if you live in an area with sustained sub-zero temperatures. The liquid provides a physical barrier that air simply cannot match in complex valve systems.
Mastering how to winterize rv washer components ensures that your first trip in the spring is spent enjoying the outdoors, rather than mopping up a flooded bathroom. Take your time, follow the sequence, and double-check your connections.
Stay safe, keep your rig in top shape, and we’ll see you on the trails next season!
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