RV Winterizing Supplies Shopping List: Order Before the Freeze

A supply list only: what to buy for RV winterizing, what to check on your own rig first, and where the procedure belongs.

To winterize an RV you generally need non-toxic RV or marine antifreeze, a way to bypass the water heater, a method to draw antifreeze into the water pump, and a few storage extras. Order before the freeze, but check three things about your own rig first so the parts fit. This page is a supply list, not a how-to: the procedure belongs in your owner's manual and, if you are unsure, with a qualified technician.

For the procedure itself, start with your manual, then read our winterizing guide for background. If the two differ, the manual wins.

Three Things to Look Up First

1. Your water heater. Find the brand and model on the label, and see whether it already has a bypass valve set. Whether you need a kit depends on that.
2. Your pump setup. Some rigs have a built-in winterizing connection at the pump; others need a converter kit or tubing. Check your manual.
3. Anything unusual. Ice makers, washing machines and similar appliances have their own instructions. Good Sam points readers to the manual for these.

The Core Plumbing Supplies

RV or marine antifreeze

Buy a product labeled non-toxic RV and marine antifreeze. Good Sam names exactly that type. Read the label for use in potable water systems and for the freeze-protection range, and do not substitute automotive coolant, which is not made for drinking-water plumbing. How much you need depends on your plumbing layout, so go by your manual and your rig, not a number from a list.

Water heater bypass kit

A bypass lets you isolate the water heater so antifreeze flows to the lines rather than filling the tank. Good Sam notes a heater without a bypass can waste a large amount of antifreeze, and that a bypass also helps protect against ruptured lines or a ruptured tank. Many rigs come with one installed. If yours does not, kits are sold for common heater connections, but fit varies, so match the kit to your heater's plumbing or ask a technician to add one.

Separately, the Suburban manual says to drain the heater when it faces freezing temperatures. Follow the heater maker's draining steps for your model, and let a technician handle anything beyond that.

Pump converter kit or inlet tubing

Antifreeze has to reach the pump. Good Sam recommends either a water pump converter kit or tubing from the pump inlet into a jug of antifreeze. A converter kit is a fitting you install once; tubing is cheaper and easier to store. Check the pump inlet size and fitting type on your own rig before ordering either, because kits are not universal.

Blow-out adapter and air source

Some owners clear the lines with compressed air, usually with an adapter that screws onto the city water inlet. If you go this way, your manual sets the maximum air pressure and tells you whether blowing out the lines is acceptable for your plumbing. Use a regulator and gauge so you can stay inside that limit, and do not guess. No air pressure number is given here on purpose.

Smaller Plumbing Parts Worth Having

• Replacement drain caps or plugs. Replace cracked or missing ones so the low-point drains close properly.
• Hose washers and gaskets. Cheap, and easy to replace while the system is open.
• A clean bucket and funnel. For catching drained water and handling antifreeze.
• A spare water filter cartridge, or none. Check your manual about removing a canister filter during storage. See our water filter guide for the cartridge side.

Storage Extras That Often Share the Cart

Plumbing is only part of storage prep. Good Sam also lists fuel stabilizer for the fuel tank on a motorized RV, sealant for gaps, spray lubricant for locks and hinges, a breathable cover, wood blocks under tires, baking soda for the refrigerator and mouse traps. Ask your dealer about sealants that are compatible with your rig, as Good Sam suggests, and see our guides to RV covers and storage prep for the rest.

Quick Reference Table

Order Before the Freeze

The best time to buy winterizing supplies is when the nights first start dropping, not when a freeze warning appears. Allow for shipping, and do not tie this purchase to a sale weekend if a hard freeze is likely first. Our Black Friday sorting guide explains why deadline-driven items fall into the buy-when-needed pile.

Ordering Mistakes to Avoid

• Buying a bypass kit without checking the heater. Fittings vary, and a kit that does not match your heater's plumbing is a returned kit.
• Assuming one jug is enough. The amount depends on your plumbing, and a heater without a bypass takes far more. Read your manual and plan with a margin.
• Skipping the label. The antifreeze label should say it is for potable water systems. If it does not, do not use it in your lines.
• Forgetting the extras. Drain caps, washers and a funnel are cheap and easy to forget until the day you need them.
• Ordering at the last minute. A winterizing weekend with a missing part often ends with a lot of driving.

If You Do Not Winterize for Storage

Some owners use their RV through the cold months and never fully winterize. That is a different set of choices, because the rig stays in service. Our cold-weather camping guide and heated hose comparison cover staying in service through a freeze. Your manual still decides what is safe to leave in the system.

A Short Order Sequence

Start with the parts whose fit you must confirm: the bypass kit, the pump kit and the blow-out adapter. Order those first, because a wrong fitting takes the longest to fix. Add antifreeze and the small parts afterward, then storage extras last. Keep the receipts and listing pages together until the job is done, so you can return anything that does not match.