🧰 Tools & Materials You’ll Need
- RV and marine antifreeze (non-toxic propylene glycol) — never automotive antifreeze
- A water-heater bypass kit, if your RV does not already have a bypass valve
- An air compressor with a regulator and a blow-out adapter for the city-water inlet
- A socket or wrench for the water-heater drain plug or anode rod
- A hand pump, siphon hose or your RV’s built-in winterizing intake
- A moisture absorber, rodent deterrents and a breathable RV cover
📋 Winterizing, Step by Step
1 Pick Your Method and Read Your Manual
Procedures differ by RV and by plumbing layout. Your owner’s manual overrides this guide.
- Blow out the lines with compressed air, then add antifreeze to the drain traps. Many owners use both methods together.
- Fill the lines with antifreeze using a pump or intake wand. This is simpler, but it uses more antifreeze.
- If your RV is built for four-season use with heated tanks, ask the manufacturer what winterizing it still needs.
2 Drain Everything
Water left in tanks and lines is what freezes and splits fittings.
- Open all low-point drains and drain the fresh-water tank.
- Dump and flush the grey and black tanks at a dump station.
- Drain the water heater only when it is cool and not under pressure, then remove the drain plug or anode rod per the manual.
- Leave drains open once the tanks are empty.
3 Bypass the Water Heater
Without a bypass, you would fill the tank with antifreeze you do not need.
- Use the built-in bypass valves or install a bypass kit.
- Confirm that antifreeze can’t reach the water-heater tank before you start pumping.
4 Blow Out the Lines
Compressed air pushes remaining water out of the pipes. Too much pressure damages fittings.
- Fit the blow-out adapter to the city-water inlet and set your regulator to no more than about 40 psi (275 kPa).
- Open each faucet one at a time — hot and cold — until only air comes out. Include the toilet valve, outside shower and any washer hookups.
- Close each faucet as it clears, then disconnect the air supply.
5 Add Antifreeze to the Traps
The drain traps hold water even after the lines are empty.
- Pour a generous amount of RV antifreeze into each sink and shower drain, and run the toilet until the bowl holds a little.
- If you use the pump method, run each faucet until you see pink antifreeze at hot and cold.
- Pour a little antifreeze into the grey and black tank drains if the manual recommends it.
6 Don’t Forget the Hidden Water
Small pockets of water in appliances and filters are easy to miss.
- Remove and drain water filters and cartridges.
- Follow the manual for the ice maker and refrigerator water line, if you have one.
- Drain or protect the washer, outside shower and exterior water connections.
7 Batteries and Electrical
Cold drains batteries, and a flat battery can freeze and crack.
- Fully charge batteries, then remove and store them in a cool, dry place, or connect a battery maintainer if the RV will have power.
- Lithium batteries have their own rules — many shouldn’t be charged below freezing. Check with the manufacturer.
- Turn off the main disconnect and any parasitic loads if the batteries stay in the RV.
8 Propane, Food and Pests
An RV left with food and open gaps becomes a mouse hotel.
- Shut off the propane at the tanks and turn off appliances.
- Remove all food, soaps and anything that attracts rodents. Prop the fridge and freezer doors open.
- Seal gaps around utility openings with materials rodents can’t chew, and avoid loose poison baits inside the RV.
9 Roof, Seals and Tires
Snow and ice find every small leak.
- Wash the roof and inspect and reseal seams before winter.
- Close slide-outs and awnings according to the manual, and treat rubber seals with a conditioner.
- Inflate tires to the recommended pressure, protect them from UV and, if possible, park on boards rather than wet ground.
10 Moisture, Cover and Storage
Trapped moisture causes mould and mildew over a long winter.
- Open cabinet and closet doors and place moisture absorbers inside.
- Use a breathable RV cover rather than a plastic tarp.
- Visit the RV during winter — especially after a thaw — to check for leaks, pests and condensation.
⚠️ Common Mistakes
- Using automotive antifreeze, which is toxic and not meant for drinking-water systems.
- Forgetting to bypass the water heater.
- Blowing out lines at too high a pressure.
- Leaving low-point drains closed after draining.
- Missing filters, ice makers and outside showers.
- Leaving food or soap inside.
🌷 Spring De-Winterizing
In spring, reconnect the water heater and flush the system until the antifreeze is gone. Sanitize the fresh-water system, reinstall filters, close all drains and pressurize slowly, checking every fitting for leaks before you load the RV.
📝 Keep a Winterization Record
Write down every drain plug opened, every bypass valve changed and every filter removed. Take photos of the plumbing bay. In spring, your list tells you what to put back.
🧊 After the Water System
- Fully charge and disconnect or maintain batteries
- Turn off and secure propane
- Remove food, clean the fridge and prop its door
- Seal gaps against mice
- Check tires, roof and seals
❓ Winterizing FAQ
How cold does antifreeze protect to?
Products are rated to specific temperatures. Choose one rated for the lowest temperature your region sees.
Can I winterize and still use the RV in winter?
Only partly. Winter camping requires a different setup, with heated water lines and tanks.
📚 More Winterizing and Storage Guides
- Winterizing plumbing with antifreeze – choosing and using RV antifreeze
- Winter storage preparation checklist – everything to do before storage
- Battery storage in Canadian winters – keeping batteries healthy
- Preventing and thawing frozen lines – if lines freeze
- Covers, snow loads and roof protection – protecting the roof
- Rodent and pest protection – keeping pests out
- Spring dewinterization and inspection – getting ready for the new season
- Choosing a winter storage facility – where to store