How to Winterize Your RV: Protecting Your Home on Wheels from Winter's Wrath

Frost creeps across the windshield like nature's own etching, and suddenly that autumn camping trip feels like a distant memory. Every year, thousands of RV owners face a critical decision as temperatures plummet: properly prepare their recreational vehicle for winter storage or risk catastrophic damage that could cost thousands in repairs. The difference between a smooth spring startup and a nightmare of burst pipes often comes down to a few crucial hours of preparation in the fall.

I learned this lesson the hard way back in 2018. After procrastinating through October, I hastily threw a tarp over my Class C and called it good. Come April, I discovered split water lines, a cracked water heater tank, and damage that totaled nearly $3,000. That expensive education transformed me from a winterization skeptic into someone who now blocks out an entire weekend each October for the process.

Understanding Why Winterization Matters

Water expands roughly 9% when it freezes. In the confined spaces of RV plumbing, this expansion becomes a destructive force that can split copper pipes, crack plastic fittings, and destroy expensive components like water pumps and hot water heaters. But here's what many people miss: it's not just about the plumbing. Winter's assault on an unprepared RV is comprehensive, attacking everything from rubber seals to battery cells.

The real kicker? Insurance companies often deny claims for freeze damage if you can't prove proper winterization. I've watched fellow RVers learn this painful truth after discovering their "comprehensive" coverage had more holes than Swiss cheese when it came to negligence-related damage.

The Great Antifreeze Debate

Before diving into the nuts and bolts, let's address the elephant in the room: RV antifreeze. Pink stuff, propylene glycol-based, non-toxic – you've probably heard the basics. What you might not know is that the antifreeze industry has been quietly revolutionizing their formulas over the past decade.

Traditional -50°F antifreeze works fine for most climates, but I've started using the newer -100°F formulas after a particularly brutal polar vortex caught me off guard in Minnesota. The extra protection costs maybe $10 more total, which seems trivial compared to potential damage. Some folks swear by the compressed air method instead of antifreeze, and while it can work, I've seen too many missed low spots lead to frozen disasters to recommend it for anyone but the most meticulous DIYers.

Draining the Water System

Start with the fresh water tank. This seems obvious, but you'd be amazed how many people drain it halfway and call it done. The tank's design usually includes a low spot that holds water even after the main drain appears empty. I use a shop vac to suck out that last stubborn gallon – learned that trick from an old-timer at a KOA in Wyoming.

Next comes the water heater. Here's where things get interesting. Most manuals tell you to simply open the drain plug, but they don't mention the sediment that accumulates at the bottom. I flush mine with a water heater rinse wand every fall. It's disgusting what comes out, even from a relatively new unit. That calcium and mineral buildup acts like concrete if left to freeze and thaw repeatedly.

The bypass valve situation on water heaters drives me crazy. Every manufacturer seems to have their own cryptic system. Some have one valve, some have three, and I once encountered a Jayco with a setup that required an engineering degree to decipher. Take photos of your valve positions before you start – your spring self will thank you.

The Antifreeze Process

Once everything's drained, it's antifreeze time. The water pump conversion kit makes this infinitely easier, though I managed without one for years using the gravity fill method. If you're going the kit route, don't cheap out on the $15 hardware store version. The $30 kits with quality fittings save hours of frustration.

Here's something nobody tells you: antifreeze doesn't flow like water. It's thicker, especially when cold, so it moves through the system differently. I run my water pump for 30-second intervals with 30-second breaks to prevent overheating. Learned that after burning out a pump trying to rush the process.

Work from the closest faucet to the furthest, and don't forget the outside shower. That outside shower has probably caused more freeze damage than any other single component. It's easy to miss because it's often on a separate line that doesn't fully drain.

The toilet requires special attention. After running antifreeze through it, I pour an extra quart directly into the bowl and flush it into the black tank. Some people skip this, figuring the black tank doesn't need protection. They're usually the ones posting panicked messages on RV forums come spring about their cracked black tank.

Beyond the Plumbing

Winterization extends far beyond pipes and tanks. Your RV's batteries face their own cold weather challenges. A fully charged battery can survive to about -75°F, but a discharged one freezes at 32°F. I pull mine completely and store them in my basement on a battery tender. Yes, it's a pain, but replacing deep cycle batteries every year is a bigger pain.

The refrigerator needs attention too. Modern RV fridges with ice makers have water lines that everyone forgets about. Even if you never use the ice maker, that line holds water. I disconnect it at both ends and blow it out with compressed air, then cap the connections.

Speaking of appliances, your washer-dryer combo (if equipped) has its own winterization procedure that's usually buried on page 847 of the manual nobody reads. These units can hold surprising amounts of water in places you can't see. I run a winterization cycle with antifreeze, then leave the door open all winter to prevent mold.

Exterior Preparation

The roof deserves its own dissertation. I spend more time on roof prep than any other single aspect because water infiltration from above causes more total RV damage than freezing pipes ever could. Every seam, every protrusion, every potential entry point gets inspected and resealed if necessary.

Dicor self-leveling sealant has become my religion. I buy it by the case now. But here's the thing – you can't just glob it on and hope for the best. Surface prep matters. I clean with acetone, let it dry completely, then apply in temperatures above 50°F. Trying to seal in cold weather is like trying to spread cold peanut butter on soft bread.

The slide-outs present their own challenges. Those rubber seals take a beating from UV and weather. I treat mine with 303 Aerospace Protectant twice a year. Some people use various homemade concoctions, but I've seen too many seals destroyed by the wrong products to experiment.

Interior Moisture Control

Moisture inside a closed-up RV becomes your enemy number one. It leads to mold, mildew, and that awful musty smell that greets you in spring. I use DampRid containers, but placement matters. One in the bathroom, one in the bedroom, one in the main living area. But here's the pro tip: empty your closets and cabinets first. Moisture loves to hide in enclosed spaces full of fabric.

Some people run dehumidifiers all winter, but unless you're checking on your RV regularly, this seems risky. Power failures happen, and a dehumidifier tank that overflows can cause more damage than the moisture it was preventing.

The Pest Prevention Protocol

Mice view your winterized RV like a five-star hotel with a free breakfast buffet. I've tried everything: steel wool, dryer sheets, Irish Spring soap, ultrasonic devices. Here's what actually works: a combination approach. Steel wool in every possible entry point, including around the propane lines and electrical cord access. Then I place cotton balls soaked in peppermint oil in strategic locations, refreshing them monthly.

The real secret? Remove every single crumb of food. I mean everything. That includes canned goods (mice can chew through aluminum), spices, coffee, tea bags, even toothpaste. One forgotten granola bar can fuel a mouse colony all winter.

Propane System Considerations

Most people just turn off the propane and forget about it. But propane systems need love too. I remove the tanks completely and store them outside (never in an enclosed space). Before disconnecting, I burn off the lines by running a stove burner until it goes out. This prevents that sulfur smell when you reconnect in spring.

The propane regulator gets covered with a proper cover, not a plastic bag that traps moisture. Moisture in the regulator leads to freezing issues that manifest as mysterious propane problems come spring.

Documentation and Final Thoughts

I maintain a winterization checklist that's evolved over the years into a multi-page document. It includes not just what to do, but when I did it and any issues I noticed. This record has saved me countless hours of troubleshooting. That slow leak in the city water connection? Noted in October, fixed in April before it became a problem.

My final walk-through includes taking photos of everything: valve positions, switch settings, thermostat readings. Modern phones make this documentation painless, and it eliminates the spring guessing games.

Some RV parks offer winterization services, and for many people, the $150-300 cost provides peace of mind. But I'd argue that doing it yourself teaches you invaluable lessons about your RV's systems. When something goes wrong at a remote campsite, that knowledge becomes priceless.

The process typically takes me a full day now, though my first attempt stretched across an entire weekend. Each RV is different, and you'll develop your own rhythm and preferences. The key is starting before the first freeze threatens. Rushing leads to mistakes, and mistakes in winterization tend to be expensive.

As I write this in my properly de-winterized RV, preparing for another season of adventures, I'm reminded that winterization is really about respect – respect for your investment, respect for the forces of nature, and respect for the future memories you'll create in your home on wheels. Those few hours in October ensure countless hours of enjoyment when the snow melts and the road calls again.

Remember, there's no single "right" way to winterize. Climate, RV type, storage situation, and personal preference all play roles. What matters is developing a thorough system and sticking to it. Your future self, enjoying that first spring camping trip without dealing with freeze damage, will appreciate the effort.

Authoritative Sources:

Woodall's RV Owner's Handbook. Birmingham: Woodall Publications Corp, 2021.

National Fire Protection Association. NFPA 1192: Standard on Recreational Vehicles. Quincy: National Fire Protection Association, 2021.

Recreation Vehicle Industry Association. RV Quick Facts. Reston: RVIA.org, 2023.

Moeller, Bill, and Jan Moeller. RV Repair & Maintenance Manual. 4th ed. New York: McGraw-Hill, 2020.

United States Environmental Protection Agency. "Antifreeze." EPA.gov. Environmental Protection Agency, 15 Sept. 2023.