If you’re putting together a DIY winterization kit, a few well-chosen products can go a long way toward preventing issues like frozen plumbing, stale fuel, moisture damage, corrosion, and an unpleasant spring cleanup. Here’s what belongs on the shopping list and why choosing the right products for your RV winterization kit matters more than you think.
RV Antifreeze
If there’s one winterization product you don’t want to get wrong, it’s antifreeze. Unlike automotive antifreeze, which goes into a closed cooling loop, RV antifreeze is poured directly into your plumbing—meaning it flows through the same pipes and faucets as your drinking water. Use the wrong product and you can contaminate the rig’s entire potable water system.
When shopping for RV winterization supplies, look for non-toxic, propylene glycol-based RV/marine antifreeze specifically labeled for RV plumbing systems. Traditional automotive antifreeze typically uses ethylene glycol, which is toxic and not something you want introduced to your ice maker. Both are brightly colored liquids sold in jugs, so read the labels carefully before grabbing one off the shelf.
How much antifreeze you need depends on your RV and its plumbing layout, as well as your chosen winterization method. A small trailer or van with a single sink may only require 1 to 2 gallons, while large or multi-bathroom rigs with washing machines and other water-use appliances can require 4 to 6 gallons. These estimates assume you are bypassing the water heater, which routes antifreeze around the tank rather than through it—and can save you significant time and money.
Some RV owners prefer to use an air compressor to blow water out of the lines and leave only air behind. Even with this method, you will still need 1 to 2 gallons of RV antifreeze to protect vulnerable areas like toilet seals, P-traps, and holding tanks. If you’re facing an extremely cold winter, you may want to consider a hybrid approach: blowing the lines out with air first and then pumping antifreeze through the lines.
For more insights on properly winterizing your RV’s plumbing system, check out How To Keep RV Pipes From Freezing.
Tank Cleaner
Before you pump antifreeze through the plumbing, give your tanks and sanitation system a proper cleanup. Winter storage is a lousy time to leave behind waste, grease, soap residue, mineral deposits, and other buildup that can harden or create odors. This isn’t about making the tanks sparkle, but rather entering the off-season with a system that’s as clean and empty as possible so you don’t get any nasty surprises come spring.
As a quick refresher:
- the water tank holds clean, potable water
- the gray tank holds dirty water from the shower and the kitchen sink
- the black tank holds waste and toilet water
The gray and black tanks are where you want to focus your attention when winterizing. After emptying and flushing them with water, add a dedicated holding tank cleaner—through the toilet for the black tank and through the sink or shower drains for the gray tank—to help break down any remaining residue. Enzyme and bacteria-based formulas work well here, as they’re biodegradable, environmentally friendly, and provide longer-lasting results compared to chemical treatments. Let the cleaner work for the recommended dwell time, then drain completely before adding any antifreeze.
When shopping, don’t confuse tank treatment for tank cleaner. Cleaners are designed to remove existing buildup and are what you want for winterization prep, while treatments are generally used during normal operation to break down waste and control odors. If your tank sensors have been giving you inaccurate readings, look for a formula specifically designed to address sensor buildup—winterization is a natural opportunity to tackle that while the tanks are already empty.
Moisture Absorbers
Once your RV is closed up for the season, maintenance worries don’t disappear with the warm weather. Moisture is a problem that’s easy to forget about until spring, but temperature swings (even in winter) can cause condensation to build up inside a stored RV. To keep damp air from causing musty odors, mildew, stains, and corrosion, moisture absorbers or “desiccants” are inexpensive and surprisingly effective combatants.
Most desiccants use one of two active ingredients: silica gel or calcium chloride. Silica gel is the gentler option—it absorbs moisture steadily and can often be dried out and reused. Calcium chloride is more aggressive, making it the better choice for long-term storage in damp climates or poorly ventilated spaces. Many desiccants are available scented or unscented, so some release a light floral or citrus fragrance that attempt to keep the interior smelling fresh. If you’re sensitive to artificial scents, look for an unscented option.
When it comes to placement, think room by room rather than dropping a single container in the middle of the RV and calling it done. Closets, bathrooms, the kitchen, and the bedroom are all prone to trapping moisture, and each one benefits from its own absorber. Hanging packets work well in wardrobes and closets, while tubs or larger pouches are better suited for open living areas and bathrooms. The more enclosed spaces your RV has, the more absorbers you’ll need.
Check absorbers periodically if you can access the RV during storage, and replace them when saturated. It’s a small habit that’s considerably cheaper than discovering a moldy mattress or warped cabinet in the spring.
Fuel Stabilizer
For motorized RVs, winterizing the living quarters is only part of the job. The engine and fuel system need attention too—and fuel stabilizer is where that process starts.
Gasoline degrades during extended storage. Oxidation causes deposits that form gum and varnish in the fuel system, clogging injectors, carburetors, and fuel lines. Ethanol-blended fuel can create additional headaches by attracting moisture and accelerating corrosion. Adding a quality fuel stabilizer before storage slows that degradation and helps protect the system through months of inactivity.
Choose a stabilizer that is formulated for the type of fuel and engine in your RV and add it before the RV goes into storage, not after it’s already been sitting. Follow the product’s treatment ratio carefully, since different formulas treat different amounts of fuel.
Once the stabilizer is added, run the engine for 10–15 minutes to circulate the treated fuel through the entire system, including the carburetor or fuel injectors. Stabilizer that sits only in the tank won’t protect the rest of the fuel system. Skipping this step is one of the most common mistakes RV owners make.
For a broader look at preparing your engine for cold-weather storage, check out Winter Fuel Prep for Smooth Starts.
Wash & Wax
Washing and waxing before winter storage is one of the more practical things you can do to protect your RV’s exterior during a long off-season. (Besides, who wants to put a dirty RV into storage and pull out an even dirtier one in the spring?) A thorough wash removes surface muck like road film, bugs, and tree sap that can etch or stain the surface if left to sit for months, while a quality wax adds a layer of protection against UV degradation, moisture, and airborne grime.
When shopping for wash and wax products, it’s worth seeking out an RV-specific product. Fiberglass, gel coat, painted surfaces, trim, and decals have different care requirements than a typical automotive finish, and products not designed for these materials can dull or damage them over time. Options like Thetford RV Premium Wash & Wax and Camco Pro-Strength Wash & Wax are specifically formulated for RV exteriors and handle both jobs in one step, making them a practical choice when you’re already working through a winterization checklist.
Lubricants
After sitting for months, moving parts have a way of becoming stubborn—especially when temperatures drop. A little preventive lubrication before storage can help prevent sticking, corrosion, and unnecessary wear. However, this isn’t a situation where one can of spray lubricant covers everything.
Different components need different products. Dry silicone or PTFE sprays work well for locks, window tracks, hinges, and exposed mechanisms, while hitch components generally call for grease. Electrical connections and terminals should be treated with dielectric grease specifically, and slide-out mechanisms are their own category altogether. For those parts, use only products specifically approved for your slide-out system, and be aware that silicone spray, while useful elsewhere, can damage the rubber seals on slide-out components if applied incorrectly.
When in doubt about any component, check the RV or component manufacturer’s recommendations before applying anything—the wrong product can attract dirt, degrade rubber, or create buildup that causes more problems than it prevents.
Build Your Winterization Shopping List
Winterizing an RV is partly a checklist of physical steps, but the products you use during those steps matter just as much. The wrong antifreeze can contaminate a potable-water system. Skipping tank cleaning can leave behind buildup and odors. Ignoring moisture can lead to mildew and corrosion, while untreated fuel can create problems when you're ready to hit the road again.
Stock up on RV-approved winterization products before temperatures drop so you’ll have what you need to put your RV to bed properly and make spring startup a lot less painful. Parts Via carries the winterization supplies and maintenance products to get the job done, with fast, FREE ship-to-store pickup at checkout.