How to Winterize a Camper: Protecting Your Home-on-Wheels from Freezing Temperatures

The first time I watched water expand and crack a pipe in my neighbor's RV, I understood viscerally why winterization isn't just another item on the seasonal checklist—it's an act of preservation that can save you thousands of dollars and countless headaches. That was back in 2018, and since then, I've winterized dozens of campers, from vintage Airstreams to modern fifth wheels, each teaching me something new about the delicate dance between water, cold, and the intricate plumbing systems hidden behind those cozy RV walls.

The Physics Behind the Process

Water is peculiar. Unlike most substances that contract when they freeze, water expands by about 9%. This seemingly small percentage translates to tremendous force—enough to split copper pipes, crack plastic fittings, and destroy water pumps that cost more than your monthly grocery budget. When temperatures drop below 32°F, any water left in your RV's plumbing system becomes a ticking time bomb.

I learned this lesson the hard way during my second winter as an RV owner. Despite thinking I'd drained everything properly, a small pocket of water remained in a low spot of my fresh water tank. Come spring, I discovered a hairline crack that turned my tank into an expensive colander. That $400 mistake taught me that gravity alone isn't always enough—you need to think three-dimensionally about where water might hide.

Timing Your Winterization

The question of when to winterize splits the RV community like few other topics. Some folks swear by the first frost rule, while others wait until consistent nighttime temperatures hover around 25°F. After years of watching weather patterns and dealing with surprise cold snaps, I've settled on a more nuanced approach.

Start monitoring nighttime temperatures in early fall. When you see three consecutive nights predicted to drop below 35°F, that's your cue. This buffer gives you time to complete the process before any damaging freezes arrive. In the northern states, this typically means late September to mid-October. Down south, you might stretch it to November or even December.

But here's what the manuals won't tell you: microclimates matter. Your RV parked in a wind-swept field will experience different conditions than one sheltered by trees or buildings. I once helped winterize two identical travel trailers parked just 200 yards apart—one in an exposed area, the other tucked behind a barn. The exposed unit's water pump froze during an unexpected October cold snap, while the sheltered one sailed through unscathed.

The Great Antifreeze Debate

Walk into any RV supply store and you'll face a wall of pink antifreeze jugs, all claiming to be the best solution for winterization. The truth is more complex than the marketing suggests. RV antifreeze—specifically the non-toxic, propylene glycol-based variety—comes in different formulations rated for various temperatures.

Most standard RV antifreeze protects down to -50°F, which sounds excessive until you consider wind chill and the fact that antifreeze can become diluted by residual water in your lines. I've experimented with the -100°F varieties, and honestly, unless you're wintering in Alaska, it's overkill that just lightens your wallet.

What matters more than the temperature rating is the quality of the antifreeze itself. Cheap antifreeze often contains more water and less active ingredient. I learned to spot quality by the weight of the jug—good antifreeze feels noticeably heavier than the bargain brands. Also, fresh antifreeze should be vibrant pink or red. If it looks pale or cloudy, it's either old stock or inferior quality.

Draining: The Foundation of Protection

Before a drop of antifreeze enters your system, you need to remove as much water as possible. This isn't just about opening valves—it's about understanding the hidden geography of your RV's plumbing.

Start with the fresh water tank. Open the drain valve and let gravity do its work, but don't stop there. Rock the RV gently side to side (if it's a smaller unit) or use compressed air to blow out the remaining water. I've pulled nearly a gallon of additional water from "empty" tanks using compressed air.

The water heater demands special attention. First, ensure it's completely cool and turn off the power source. Then locate the drain plug—usually a plastic plug on the outside of the unit. Here's where experience pays off: have a bucket ready because the initial rush of water can surprise you. Also, that anode rod you should be checking annually? Now's the perfect time to inspect it for corrosion.

Don't forget the city water inlet. This fitting has a check valve that can trap water. I use a blow-out plug here, applying about 30 PSI of compressed air to clear the line. Too much pressure can damage seals, so resist the urge to crank up your compressor.

The Bypass Ballet

Water heater bypass valves confuse more new RV owners than any other winterization component. These valves, usually a set of two or three near your water heater, redirect antifreeze around the tank so you don't waste six to ten gallons of expensive antifreeze filling it.

The configuration varies wildly between manufacturers. Some use a simple two-valve system, others have three valves, and I've even seen some with a single lever that does it all. Take photos before you start—trust me, come spring you'll appreciate the visual reminder of which position is "normal."

Here's a trick I picked up from an old-timer in Arizona: after setting your bypass valves, run a bit of water through the system to verify the bypass is working. If water comes out of your hot water taps, you've successfully bypassed the heater. If not, recheck your valve positions.

The Antifreeze Journey

With everything drained and bypassed, it's time for the main event. You have two options: pumping antifreeze through the system or using compressed air followed by antifreeze in the traps. I'm firmly in the antifreeze-throughout camp, having seen too many freeze damages from the compressed air method.

Install a winterization kit if your RV doesn't have one built-in. This simple device lets you draw antifreeze directly from the jug into your water pump. Start with the kitchen sink, opening both hot and cold until pink antifreeze flows steadily. Work your way through every fixture—bathroom sink, shower, toilet, outdoor shower if equipped. Don't forget less obvious water outlets like the washing machine connection or ice maker line.

The toilet requires special attention. Pour antifreeze directly into the bowl and flush it into the holding tank. Add extra antifreeze to the black tank through the toilet—about a gallon should do it. This prevents any remaining waste from freezing and damaging the tank.

The Forgotten Spaces

Every RV has hidden water pockets that the standard winterization process might miss. The washing machine, if equipped, needs its own procedure. Run a cycle with antifreeze, ensuring it reaches the pump and drain hose. Dishwashers require similar treatment.

Ice makers are particularly vulnerable. The small water lines freeze quickly, and replacement parts are surprisingly expensive. Disconnect the water supply and blow out the line with compressed air, then run antifreeze through if possible.

Don't overlook the water pump itself. After running antifreeze through all fixtures, disconnect the pump's inlet line and pour antifreeze directly into it while running the pump briefly. This ensures the pump chamber is fully protected.

Exterior Considerations

Winterization extends beyond plumbing. Your RV's exterior needs attention too. Start with the awning—ensure it's completely dry before storing. Trapped moisture leads to mold and fabric degradation. I learned this after opening my awning one spring to find it looked like a science experiment.

Seal any exterior openings where mice might enter. Steel wool stuffed into gaps, followed by expanding foam, creates an effective barrier. Pay special attention to areas where plumbing or wiring enters the RV. Mice can squeeze through openings the size of a dime, and they view your RV as a cozy winter resort.

Remove batteries and store them somewhere warm. Cold severely reduces battery capacity, and a dead battery can freeze and crack. If you must leave batteries installed, invest in a quality battery tender that can handle temperature extremes.

Interior Preservation

While antifreeze protects your plumbing, moisture is your interior's enemy. Place moisture absorbers throughout the RV—I use both commercial products and homemade solutions (charcoal briquettes in breathable bags work surprisingly well). Open cabinet doors and drawers slightly to promote air circulation.

Clean the refrigerator thoroughly and prop the door open. A closed, empty refrigerator develops odors that seem to permanently embed in the plastic. The same goes for the freezer. Some people stuff the fridge with crumpled newspaper to absorb odors and moisture—it works, but remember to remove it come spring.

Remove all food, including canned goods. Temperature fluctuations can cause cans to burst, creating a mess that attracts pests. I once found a can of tomato soup that had exploded in a client's RV—the cleanup took hours and the smell lingered for months.

The Spring Awakening

De-winterization is winterization in reverse, but with its own quirks. Flush the antifreeze from your system thoroughly—I run fresh water through every fixture for at least five minutes. The water heater needs special attention; fill and drain it twice to remove all antifreeze traces.

That first spring shower might taste slightly sweet from residual antifreeze. While RV antifreeze is non-toxic, it's not exactly refreshing. Run the water heater through a full cycle before using hot water for cooking or drinking.

Check for leaks carefully during de-winterization. Sometimes fittings that seemed fine in fall develop issues over winter. Run water through each fixture individually, checking underneath for drips. Finding a small leak in spring is far better than discovering major damage next fall.

Regional Variations and Personal Touches

Winterization isn't one-size-fits-all. In the Pacific Northwest, where humidity accompanies cold, extra moisture control becomes critical. In the dry Southwest, you might worry less about interior moisture but more about UV damage to seals and gaskets during storage.

I've developed my own winterization ritual over the years. I play the same album (Tom Petty's "Full Moon Fever," if you're curious) during the process. It times out perfectly—when "Runnin' Down a Dream" ends, I should be pouring that final gallon of antifreeze. These personal touches make a necessary chore feel less like work and more like a seasonal tradition.

Some RVers add a splash of fabric softener to their antifreeze, claiming it makes spring flushing easier and leaves a fresh scent. I tried it once—the science is dubious, but the placebo effect of thinking your pipes smell "April fresh" has its merits.

The Cost-Benefit Analysis

Professional winterization typically runs $150-300, depending on your area and RV size. DIY costs about $50-75 in materials. But the real savings come from avoiding damage. A cracked water pump costs $200-400. Burst pipes can run into thousands. A split fresh water tank? You're looking at $500 minimum, plus installation.

I've noticed professionals often rush through the process, especially during the busy fall season. They'll protect your plumbing adequately, but might skip the interior moisture control or exterior pest-proofing that makes the difference between a smooth spring startup and unpleasant surprises.

Final Thoughts from the Trenches

After all these years and countless gallons of pink antifreeze, I've come to view winterization as a meditation on preparedness. There's something deeply satisfying about methodically protecting your investment, knowing you've addressed every vulnerable point.

The process has taught me patience and attention to detail that extends beyond RV maintenance. It's shown me that prevention truly is worth pounds of cure, and that understanding the why behind each step makes you a better caretaker of your equipment.

Every spring, when I turn that water pump on for the first time and hear it hum to life without leaks or damage, I'm reminded that those few hours spent winterizing were hours well invested. Your future self will thank your present self for taking the time to do it right.

Remember, your RV is more than aluminum and fiberglass—it's freedom on wheels, memories waiting to be made, and adventures yet to come. Protecting it through winter ensures those adventures continue for years to come. Take your time, be thorough, and maybe find your own soundtrack for the process. Before you know it, winterization becomes less of a chore and more of a ritual marking the changing seasons.

Authoritative Sources:

Woodall's RV Owner's Handbook. Woodall's Publications Corp, 2019.

National RV Dealers Association. RV Service Technician Handbook. RVDA Publications, 2020.

Moeller, Bill, and Jan Moeller. RV Repair & Maintenance Manual. McGraw-Hill, 2018.

Recreation Vehicle Industry Association. "RV Quick Facts." RVIA.org, Recreation Vehicle Industry Association, 2021.

U.S. Department of Energy. "Freeze Protection for Solar Water Heating Systems." Energy.gov, Office of Energy Efficiency & Renewable Energy, 2020.