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RV Winterizing: The Plumbing Sequence That Prevents Freeze Damage
RV Winterizing: The Plumbing Sequence That Prevents Freeze Damage
The first RV I bought came with a story from the previous owner: his brother-in-law had stored it one winter without winterizing the plumbing, it had cracked the water pump, the fresh water tank fitting, and three supply line connections. The repair was over two thousand dollars on a five-thousand-dollar RV. He sold it to me once it was fixed, and the story came free with the purchase. I've never skipped the winterizing routine in the years since.
Bypass the water heater first
This is the step that most instructions mention but beginners sometimes overlook. Your RV water heater holds six to ten gallons of water. If you pump RV antifreeze through the entire water system without bypassing the heater, you use three to four times as much antifreeze as you need to just to fill the heater tank before it reaches the rest of the system. Most RVs have a water heater bypass kit installed, usually a set of valves near the water heater. Close the two valves that supply the heater and open the bypass valve that routes water directly from the cold supply to the hot supply side. This isolates the heater from the system. Then drain the heater separately: open the pressure relief valve briefly, remove the anode rod or drain plug at the bottom, and let it drain fully. Reinstall the plug when empty.Drain the system and pump in antifreeze
Open every faucet in the RV — kitchen, bathroom, exterior shower if there is one — and the low-point drain valves if your RV has them. Let the system drain under gravity until water stops flowing from everything. Flush the toilet several times to clear the toilet valve and let the tank drain. Install a water pump conversion kit if you don't already have one — this lets you connect a tube from the inlet side of the pump directly into a bottle of non-toxic RV antifreeze (pink propylene glycol, not automotive). Turn on the pump, open each faucet one at a time, and wait until you see pink antifreeze flowing from it, then close it. Do the toilet, the exterior connections, and the shower. Pour about four ounces directly down each drain to protect the P-traps. You need roughly two gallons of antifreeze for a typical RV with a properly bypassed water heater. Three gallons is comfortable and leaves margin for any missed areas.Clean the interior and address rodent access
Remove all food from every storage compartment. Inspect every pantry shelf and drawer — crumbs and packaging attract rodents, and a warm enclosed RV is exactly where they want to winter. Take out all medications, toiletries with organic scent, and any candles or organic materials. Walk the exterior and look for any gap or penetration larger than a dime — where water lines, electrical conduit, or slide-out mechanisms create potential entry points. Pack these with copper mesh or steel wool before winterizing. Rodents chew through foam and rubber but are deterred by metal mesh. Clean and prop open the refrigerator and freezer to prevent mildew and odor from sealed moisture.Battery storage and exterior care
Disconnect the house batteries and bring them inside if storage temperatures will drop below freezing. A battery charger maintainer hooked to house batteries in a garage keeps them at full charge without overcharging and means they're ready in spring without damage. Cover the RV with a breathable RV cover rather than a solid plastic tarp. Plastic traps moisture against the exterior surfaces and can cause the kinds of problems it's supposed to prevent. Breathable fabric allows any trapped humidity to escape while protecting against UV and physical debris.What I'd skip
Skip the temptation to "partially" winterize because the weather might stay mild. An unexpected hard freeze event in November can occur in most of the continental US and a partially winterized plumbing system is only partially protected. Do the full job. Also skip relying on air compressor blow-out alone without antifreeze follow-up. Air blows the bulk of the water out but leaves residual moisture in the pump, fittings, and traps. Antifreeze after blowing out provides the insurance against that residual. The bottom line: RV winterizing done correctly takes two to three hours and costs about thirty dollars in antifreeze. The alternative is measured in repair invoices and a spring season without your RV while it's in the shop. Ready to shop? Compare Home & Garden across stores → 📚 Or browse home & garden guides in Digital Goods →📢 Affiliate Disclosure: This article contains affiliate links. We may earn a small commission at no extra cost to you when you click through and purchase.
