Winterizing a Camper or RV, Step by Step

The first hard freeze of the season is the most expensive night of the year for camper owners who weren't ready. Water left in the lines, the pump or the water heater freezes, expands and cracks things that cost a lot to fix. Winterizing takes an afternoon. Here's how to do it.

Always check your RV's owner's manual first. Every rig has its own valves, and some have specific instructions for the water heater, ice maker or washer.

01What you'll need

• RV antifreeze (the pink, non-toxic kind made for potable water systems), usually 2 to 3 gallons for a typical camper. Never use automotive antifreeze.
• A water heater bypass kit if your camper doesn't have one built in
• A water pump converter kit or a short hose to pull antifreeze into the pump
• Basic hand tools, and a wrench or socket for the water heater drain plug or anode rod
• Optional: an air compressor and blow-out plug if you use the air method

02Step 1: Drain the holding tanks

Dump and flush the black tank first, then the gray tank, at a dump station. Close the valves when you're done.

03Step 2: Drain the fresh water tank and water heater

• Open the fresh water tank drain.
• Turn off the water heater and let it cool completely. Never drain a hot water heater.
• Open the pressure relief valve at the top of the water heater, then remove the drain plug or anode rod and let it drain.

04Step 3: Open the low-point drains and faucets

Open the low-point drain lines (usually under the camper) and every faucet, hot and cold, plus the shower, to let the water run out. Flush the toilet to drain it.

05Step 4: Bypass the water heater

Put the water heater bypass valves in bypass. Otherwise you'll pour several gallons of antifreeze into the heater tank for nothing.

06Step 5: Add antifreeze (or blow out the lines)

Close the low-point drains and faucets.

Antifreeze method: use the pump converter kit or a hose to pull RV antifreeze into the water pump. Turn on the pump. Then, one at a time, open each faucet, cold side then hot side, until pink antifreeze runs out, and close it. Start with the fixture closest to the pump and work outward. Don't forget the shower, the outside shower if you have one, and the toilet (flush until pink appears).

Compressed air method: with a blow-out plug on the city water inlet and air pressure kept low (check your manual, many recommend around 30–40 psi), blow the water out of each line one faucet at a time. Many owners do the air method and then add antifreeze to the drains and traps for extra protection.

07Step 6: Protect the drains

Pour a cup or two of antifreeze down every sink drain and the shower drain to protect the P-traps, and a little into the toilet bowl.

08Step 7: Battery, tires and seals

• Battery: charge it fully, then disconnect it or remove it and store it somewhere it won't freeze, on a maintainer if you have one. A dead battery can freeze.
• Tires: inflate to the recommended pressure and cover them to block UV.
• Roof and seals: check the roof, windows and seams for cracks and reseal before winter. Winter leaks do the worst damage.

09Step 8: Keep the mice out

Mice love a stored camper. Clean out every crumb of food, prop the fridge door open so it doesn't mold, plug any openings you can find with steel wool or foam made for rodents, and check on the camper every few weeks.

10In spring

De-winterizing is the reverse: flush the antifreeze out of the lines with fresh water, take the water heater out of bypass, refill, sanitize the fresh water system, and check every connection for leaks before your first trip.

An afternoon now saves you a cracked water pump in April. When the forecast shows the first night in the 20s, you want this done.