RV Winterization Checklist — Step-by-Step Antifreeze Method

Before you start

Buy 2–3 gallons of pink RV/marine antifreeze (propylene glycol) Only use antifreeze labeled for potable water systems. Automotive antifreeze (ethylene glycol) is poisonous and must never enter drinking-water plumbing.
Locate your low-point drains, water-heater bypass and pump inlet Ten minutes with the owner’s manual now saves an hour of crawling later. Some rigs have a built-in winterization valve on the pump.
Get a water-heater drain tool (usually a 1-1/16" socket) and Teflon tape
Remove and bypass inline water filters Antifreeze ruins filter cartridges. Pull them, and reconnect the lines or install a bypass hose.

Drain the water system

Dump and rinse the black tank, then the gray tank, at a dump station Waste left over winter sets like concrete and breeds odors you will meet again in April.
Drain the fresh water tank completely
Turn off the water heater and let it cool fully before draining Water inside can be scalding and under pressure. Electric element ON with an empty tank = dead element, so kill the breaker too.
Open a hot tap to release pressure, then pull the water heater drain plug/anode On Suburban heaters the plug is the anode rod — inspect it and replace if more than 75% consumed.
Open all low-point drains (hot and cold lines)
Open every faucet (hot + cold), shower, outdoor shower, and flush the toilet until lines run dry
Run the water pump for no more than 15–30 seconds to push out remaining water A pump running dry for minutes will burn itself out.
Close all drains and faucets once empty

Bypass and pump antifreeze

Set the water heater bypass valve(s) to BYPASS Without the bypass, the 6–10 gallon heater tank swallows your antifreeze before a drop reaches the faucets. No bypass installed? A dealer or mobile tech can add one cheaply.
Connect the pump’s winterization hose (or a siphon kit) into the antifreeze jug
Turn on the pump and open the closest faucet — cold, then hot — until it runs pink
Work through every fixture in order: kitchen, bath sink, shower, outdoor shower, toilet Farthest fixture last or closest first — just be systematic so nothing is missed. Don’t forget sprayers, ice makers and washing machines (follow appliance-specific procedures).
Flush the toilet until pink, and leave a little antifreeze in the bowl to keep the seal wet
Pour a cup of antifreeze into every P-trap: sinks, shower, tub Traps hold water by design; unprotected they crack and let sewer gas in.
Pump antifreeze through the black-tank flush line if you have one
Turn the pump off and open a faucet briefly to release pressure
Verify the city-water inlet check valve got antifreeze Push the little valve pin in until pink appears — a frozen check valve is a common spring leak.

Interior shutdown

Remove ALL food, including cans and bottles that can freeze and burst Anything edible invites rodents; anything liquid can split open.
Defrost the freezer, clean the fridge, and prop both doors open A closed, unpowered fridge grows mold you cannot un-smell.
Wipe down and dry all wet areas; leave cabinet doors open for airflow
Place moisture absorbers (or run a small dehumidifier if powered)
Remove bedding, towels and anything that holds moisture
Close blinds to protect upholstery from UV fading
Turn off the propane at the tank and all pilot lights
Seal obvious rodent entry points; set traps or deterrents Mice enter through gaps the size of a dime — check where plumbing and wiring penetrate the floor.

Exterior, batteries & storage prep

Wash the roof and exterior; inspect and reseal any cracked caulking Winter is when small seal failures become soaked insulation. Check roof seams, vents and window perimeters.
Cover roof vents (slightly cracked for airflow) and A/C unit
Disconnect batteries; store them charged in a cool, dry place — or keep on a maintainer A discharged battery freezes and dies. A fully charged one survives deep cold. Check charge monthly in storage.
Fill the fuel tank and add stabilizer; run engine/generator to circulate it Motorhomes and onboard generators only. A full tank minimizes condensation.
Inflate tires to placard pressure and cover them (or block off the ground) UV and long-term contact with damp ground age tires fast. Move the rig slightly mid-winter to avoid flat spots if you can.
Chock wheels, release or set brakes per your manual for long-term parking
Ventilated, properly sized RV cover if stored outdoors A breathable RV cover, not a plastic tarp — tarps trap moisture and grind grit into the finish.
Confirm insurance/storage arrangements and note what you winterized A dated note of what you did (bypass position, antifreeze gallons, battery location) makes spring de-winterizing painless.

RV Winterization Checklist — printed from HitchList. Progress saved online; reprint any time.

Frequently asked questions

How much antifreeze do I need to winterize my RV?

Most travel trailers and Class C rigs need 2–3 gallons of RV antifreeze if the water heater is properly bypassed and the lines were drained first. Large fifth wheels and Class A motorhomes with long plumbing runs, washing machines or ice makers can take 4–5 gallons. If you find yourself pouring in more than that, your water heater bypass is probably not closed.

Antifreeze or compressed air — which method is better?

Both work when done thoroughly. Antifreeze is the more foolproof option because you can see pink at every fixture; compressed air (30–40 PSI, never more) leaves no taste behind but risks missing low spots and check valves. Many RVers combine them: blow out the lines, then antifreeze the traps, toilet and low points.

When should I winterize my RV?

Before the first night that dips into hard-freeze territory — sustained temperatures below about 20 °F (-6 °C) will damage unprotected plumbing, and even one sharp overnight freeze can split an exposed fitting. In the northern US and Canada that typically means late October; in the transition states, watch the forecast rather than the calendar.

Can I use automotive antifreeze in my RV water system?

Never. Automotive antifreeze is ethylene glycol, which is toxic to people and pets and cannot be used in potable water plumbing. Use only pink RV/marine antifreeze made from propylene glycol and labeled safe for drinking-water systems — it is inexpensive and sold at every RV and hardware store in fall.

Do I need to winterize if my RV is in heated storage?

You can skip the antifreeze steps if the storage space reliably stays above freezing, but do everything else: dump tanks, drain the water heater, empty the fridge, pull food out, manage the batteries and add fuel stabilizer. A power outage in an unheated corner of a "heated" warehouse has cracked plenty of pipes — ask what backup the facility has.