Winter is hard on an RV that’s just sitting there. Freezing temperatures can crack water lines and split fittings from the inside, a discharged battery can freeze solid and never come back, rodents move in looking for a warm place to nest, and moisture trapped in a sealed rig quietly turns into mold by spring. The good news is that almost all of it is preventable. A few hours of prep in the fall protects your investment through the coldest months and makes getting back on the road in spring a lot easier.
The rule that drives everything below is simple. If your RV will sit anywhere that drops below freezing (32°F) for a sustained stretch, you need to protect the water system and the batteries, full stop. Everything else builds from there. Work straight down the checklist, then read the sections underneath for the how and the why.
The Full Winter Storage Checklist
Water system (the one you can’t skip)
- Dump and flush the black tank, then the gray tank, then drain the fresh tank
- Turn off the water heater and let it cool completely before draining
- Drain the water heater (remove the drain plug or anode rod, open the pressure-relief valve)
- Set the water heater bypass valve so you don’t waste antifreeze filling the tank
- Open all low-point drains and every faucet, hot and cold, plus the outside shower
- Remove any inline water filter cartridge
- Winterize the lines: run RV antifreeze through with the pump, OR blow the lines out with compressed air at 30 to 40 PSI
- Pour antifreeze into every P-trap and the toilet bowl (both methods need this)
- Leave a little antifreeze in the toilet bowl to protect the flush seal
Batteries
- Charge lead-acid and AGM batteries to 100% (a full battery resists freezing)
- Charge lithium (LiFePO4) to about 50%, and never leave it on a float charger
- Disconnect the batteries or use the battery cutoff switch to kill parasitic draws
- If your storage has power, put lead-acid batteries on a smart maintainer
- In hard-winter climates with no power on site, bring lead-acid batteries indoors
Fuel and propane
- Fill the fuel tank to about 95% to cut down on condensation
- Add fuel stabilizer, then drive or run the generator so it circulates
- Close the propane tank service valve
- Cover the propane regulator
Tires and chassis
- Inflate tires to the max pressure listed on the sidewall
- Put a barrier (plywood, plastic, cardboard) between each tire and the ground
- Cover the tires to block UV, even in winter
- Plan to move the rig every 3 months, or set it on jack stands to take weight off the tires
- Skip petroleum, silicone, and alcohol-based tire dressings
Interior and moisture
- Remove 100% of food, including sealed packages
- Empty and defrost the fridge and freezer, wipe them out, and prop the doors open
- Leave an open box of baking soda in the fridge
- Deep clean and dry every surface; never store anything damp
- Set out moisture absorbers (DampRid or similar) in cabinets, closets, and under sinks
- Run a dehumidifier or leave the furnace on low if you have power on site
- Leave cabinets and drawers open, and prop cushions and mattresses for airflow
Pest prevention
- Seal every gap in the underbody with steel wool or copper mesh, then sealant
- Install bug screens on the furnace, water heater, and fridge vents (remove before you run them in spring)
- Set out EPA-registered rodent pouches (Fresh Cab, Stay Away)
- Run a band of petroleum jelly around the power cord and hoses to stop ants
Exterior, slides, and awnings
- Wash and wax the exterior before storage
- Clean the roof and inspect every seam and seal; reseal cracks with lap sealant
- Clean the awning, let it dry completely, then retract it
- Retract the slides for snow load and seal protection
- Cover the exhaust tailpipe (and leave a note to remove it before starting)
Security and documentation
- Install a hitch or coupler lock on trailers and fifth wheels
- Add a wheel lock or boot as a visible deterrent
- Photograph the interior, exterior, and any existing damage
- Keep comprehensive insurance active; suspend collision and liability while stored
- Confirm the facility’s security features and access hours
Before you walk away
- Lock all doors, windows, and compartments
- Do a final walk-through for anything left plugged in or turned on
- Note your winterization date and method so spring startup is easy
When You Actually Need to Winterize
Winterization is driven by temperature, not the calendar. Once overnight lows start dipping below freezing for 24 hours or more, water left in your lines can freeze, expand, and crack fittings, valves, and the water heater. In most of the northern half of the country that means getting it done by late October or early November, and earlier at elevation.
There’s one exception worth knowing. If you’re paying for heated indoor storage that stays reliably above freezing, you can skip the antifreeze step, since the water in your lines never gets cold enough to freeze. For everyone parking outdoors or in an unheated unit, plan on the full water-system routine below.
The Water System Comes First
This is the part that causes the expensive damage, so it’s worth doing carefully. The goal is to get every drop of water out of the plumbing, or replace it with something that won’t freeze.
Start by dumping your tanks. Black first, then gray so it rinses the hose, then drain the fresh tank. Turn the water heater off and let it cool down completely, because draining a hot or pressurized heater is dangerous. Once it’s cool, pull the drain plug or anode rod and open the pressure-relief valve to let it empty. Most water heaters hold somewhere between 6 and 16 gallons. Then open all your low-point drains and every faucet in the rig, hot and cold, including the outside shower, and pull out any inline water filter cartridge so antifreeze doesn’t ruin it.
Before you add antifreeze, find your water heater bypass valve and set it. That keeps you from wasting several gallons of antifreeze filling a tank you just emptied. One important exception: if you have a tankless water heater, don’t bypass it. Those hold only about a liter and need antifreeze run through them per the manufacturer’s steps.
From here you’ve got two proven methods, and honestly a lot of experienced owners do a bit of both.
The antifreeze method is the most foolproof, and it’s the one to use if you’re newer to this. Use only non-toxic RV antifreeze, the pink propylene glycol kind rated to around -50°F. Never use automotive antifreeze, which is poisonous. Most rigs take 2 to 4 gallons. Use your water pump’s winterizing kit or siphon tube to draw antifreeze straight from the jug, then open each faucet one at a time, starting with the one closest to the pump, cold side then hot, until pink flows out. Hit the shower, the outside shower, and the toilet too. Then pour a cup or so into every P-trap and leave a little in the toilet bowl to protect the seal.
The compressed-air blowout method is cheaper and leaves no taste behind. You attach a blowout plug to the city water inlet and push air through the lines at 30 to 40 PSI, never more than about 45, so you don’t damage fittings. Open each faucet in turn until only air comes out. The catch is that a blowout never gets 100% of the water, because RV plumbing has low spots where water pools. So even if you blow the lines out, you still need to pour antifreeze into every P-trap and the toilet, and it’s smart to run a little through the pump.
Either way, the P-traps are non-negotiable. They hold water by design, and that water will freeze and crack the trap if you don’t get antifreeze in there.
Batteries in the Cold
A dead battery is one of the most common things people come back to in spring, and cold makes it worse. The rules split by battery type.
For flooded lead-acid and AGM batteries, charge them to 100% before storage. A fully charged battery resists sulfation and, just as important in winter, has a much lower freezing point. A discharged lead-acid battery can freeze and crack in cold weather, while a full one shrugs it off. Lithium (LiFePO4) batteries are different. Store those at around 50% charge for the best lifespan, keep them off a float or trickle charger, and never charge lithium when it’s below freezing, which can permanently damage the cells.
Whatever chemistry you have, disconnect the batteries or flip the cutoff switch. Things like propane detectors, LED boards, and stereo memory keep pulling small amounts of power even when everything looks off, and over a few months that’s enough to flatten a battery. If your storage spot has an outlet, a smart maintainer (not an old-school dumb trickle charger, which can overcharge and boil off electrolyte) keeps lead-acid batteries topped up all winter. No power at the site? In a hard-freeze climate, the simplest move is to pull the lead-acid batteries and keep them on a shelf somewhere above freezing.
Fuel, Propane, and Tires
Fill the fuel tank to about 95% before you park it. A nearly full tank leaves little room for the air that causes condensation as temperatures swing, which matters more in winter with big day-to-night differences. Add a fuel stabilizer and then drive a few miles or run the generator so the treated fuel reaches the whole system. Gasoline can start going stale in as little as a month untreated, so this step matters. For propane, close the tank service valve so nothing can leak while the rig sits unattended, and cover the regulator.
Tires take a beating over winter even sitting still. Inflate them to the max pressure on the sidewall for storage, and get a barrier under each one. Frozen ground and cold concrete make rubber brittle, and a sheet of plywood or plastic keeps the tire off it. Cover the tires too, since UV still degrades rubber in winter sun. If the rig will sit longer than about three months, either plan to move it periodically or set it on jack stands to take the weight off the tires. Skip the petroleum and silicone tire shine products, which actually react with the tire’s protective compounds and cause cracking.
Keeping the Inside Dry and Pest-Free
A sealed RV going through winter temperature swings is a moisture trap, and moisture is what grows mold. Start by removing every bit of food, even sealed packages, because pests will chew right through them. Empty and defrost the fridge, wipe it out, prop the doors open, and toss a box of baking soda inside. Then deep clean everything and make sure nothing goes into storage damp.
For moisture control, calcium-chloride absorbers like DampRid work well in enclosed spots like cabinets, closets, and under sinks, so scatter a few around and check them monthly. If you’ve got power at the site, a small dehumidifier or the furnace left on a low setting does even more. One winter-specific warning: don’t crack your roof vents for airflow the way you might in a dry climate, since you’ll just let in cold damp air and snow. Leave cabinet doors, drawers, and cushions open so air can move around inside.
Rodents are the other winter problem, because your RV looks like a warm, dry hotel to them. The only thing that reliably keeps them out is sealing the entry points. Get under the rig with a flashlight and stuff steel wool or copper mesh into every gap around wiring and plumbing, then seal over it, because mice chew straight through plain foam. Install bug screens on the furnace, water heater, and fridge vents to stop wasps and mud daubers (just remember to take those off before you fire the appliances up in spring). For the inside, EPA-registered botanical pouches like Fresh Cab and Stay Away are the vetted repellents. Save your money on dryer sheets and bar soap, which independent testing has shown mice will happily nest in.
Slides, Awnings, and the Exterior
Retract your slides for winter storage. Manufacturers recommend it, and with good reason: closed slides keep snow load and water off the seals and the slide floor, and the whole rig sits more compact and secure. Give the slide seals a clean and a rubber conditioner before you close them up.
Clean your awning, and this part matters, let it dry completely before you roll it up. A damp awning rolled away for the winter is the number one way people end up with a moldy, ruined awning by spring. Wash and wax the exterior before storage so it’s protected, and take a few minutes to inspect the roof. Check every seam and seal around vents, the AC, and the caps, and reseal any cracks with the right lap sealant. Water that sneaks through a bad seal and then freezes does a lot of damage.
Where You Store It Changes Everything
The single biggest factor in how well your RV survives winter is where it sits. Heated indoor storage is the most expensive option, but it protects against everything and can even let you skip antifreeze. Covered storage is the value sweet spot, blocking snow load, UV, and rain while costing far less than indoor. Uncovered outdoor is the cheapest, and it’s a perfectly good option if you do the prep, but plan on a cover and on knocking snow off the roof after heavy storms so the weight doesn’t stress the structure.
If you go uncovered, use a real breathable RV cover, not a plastic tarp. A tarp traps moisture underneath and causes the exact mold problem you’re trying to avoid. A good breathable cover sheds water while letting moisture escape, and a support pole underneath keeps snow and water from pooling on top. Whatever you choose, confirm the facility’s security setup and access hours before the snow flies.
A Quick Word on Spring
You don’t have to think about this yet, but knowing it’s coming helps. When you pull the RV back out, you’ll flush the antifreeze out of the lines, sanitize the fresh water system with a diluted bleach solution (bacteria can build up over the winter even after a clean winterization), reconnect and check the batteries, reset tire pressures, pull off any vent screens and pest deterrents, and test every system before you head out. One thing to never skip: don’t fire the water heater until the tank is full and the air is bled out, because running it dry destroys the element. Note your winterization date and method somewhere now, and spring-you will have a much easier morning.
Do the work once in the fall and your RV comes out of winter the way it went in. Skip it, and a cracked fitting or a moldy interior can cost you a whole season and a lot more than the afternoon it would’ve taken to prevent.
Frequently Asked Questions
Do I need to winterize my RV if I store it somewhere warm like Florida?
Usually not the full antifreeze routine. Winterizing is really about freeze protection, so if your RV never sees sustained temperatures below 32°F, you can skip the antifreeze. You still want to drain and dry the water system, clean the tanks, and control moisture, since standing water grows bacteria and odor even when it never freezes. The rule is simple: if freezing nights are possible where you’re parked, winterize.
Can I use regular automotive antifreeze in my RV?
No. Automotive antifreeze is ethylene glycol, which is toxic and should never go anywhere near your fresh water system. Use only non-toxic RV antifreeze, the pink propylene glycol kind rated to around -50°F. It’s inexpensive and available at any RV or hardware store.
How much RV antifreeze do I need?
Most rigs take 2 to 4 gallons. Small trailers land around 2 to 3 gallons, and larger fifth wheels and motorhomes are closer to 4 to 5. Buy an extra gallon so you don’t run short mid-job, and set your water heater bypass valve first so you’re not wasting gallons filling a tank you just drained.
Should I winterize with antifreeze or blow the lines out with air?
Both work, and plenty of experienced owners do a little of each. The antifreeze method is the most foolproof and the best choice if you’re newer to it. The air blowout method is cheaper and leaves no taste behind, but it never clears 100% of the water, so you still have to pour antifreeze into every P-trap and the toilet either way. If you blow the lines out, keep your compressor at 30 to 40 PSI so you don’t damage fittings.
Do I need to take the battery out for the winter?
Not necessarily. If your storage spot has power, the easiest approach is to leave lead-acid or AGM batteries in place, charge them to 100%, and put them on a smart maintainer. Charge level matters most in winter, because a full battery resists freezing while a discharged one can freeze and crack. If there’s no power at the site and you’re in a hard-freeze climate, pulling the batteries and keeping them on a shelf somewhere above freezing is the safer bet. Lithium is different: store it at about 50% and keep it off any float charger.
Should I store my RV with a full or empty gas tank?
Nearly full, with fuel stabilizer added. A full tank leaves little room for the air that causes condensation as temperatures swing, which matters more in winter. Add the stabilizer, then drive a few miles or run the generator so the treated fuel reaches the whole system before you park it.
Do I need to start my RV engine during winter storage?
This one splits opinion. Some owners start and run the engine monthly, but a brief idle doesn’t warm the engine fully and can actually drive moisture into the oil and exhaust. If you’re going to start it, drive it long enough to reach full operating temperature, otherwise you may be doing more harm than good. A generator is a clearer case: exercise it monthly for an hour or two under load.
Should I store my RV with the slides in or out?
In. Retracting the slides protects the seals and interior from snow, sun, and debris, keeps the footprint compact, and puts less stress on the mechanism. The one maintenance note is to run the slides in and out once or twice a month if you can get to the rig, which keeps the seals from taking a set.
How do I keep mice out of my RV over the winter?
Sealing is the only thing that reliably works. Get under the rig and stuff steel wool or copper mesh into every gap around wiring and plumbing, because mice chew straight through plain foam. Remove every trace of food, and set out EPA-registered botanical pouches like Fresh Cab or Stay Away. Save your money on dryer sheets and bar soap, which testing has shown mice will happily nest in.
Do I need to cover my RV if it’s stored outside?
It helps a lot, but only with the right cover. Use a breathable RV-specific cover, never a plastic tarp, which traps moisture underneath and causes the exact mold problem you’re trying to avoid. Add a support pole so snow and water run off instead of pooling on top. If you’re paying for covered or indoor storage, you don’t need a cover at all.
Is indoor storage worth the extra cost for winter?
It depends on your rig and your climate. Heated indoor storage protects against everything and can even let you skip antifreeze, which makes it worth considering for higher-value rigs or brutal winters. Covered storage is the value sweet spot for most people, blocking snow load, sun, and rain for far less. Uncovered outdoor is the cheapest and works fine as long as you do the prep and knock heavy snow off the roof through the season.
How often should I check on my RV in storage?
About once a month. A quick visit lets you confirm the cover is secure, empty or refresh the moisture absorbers, check tire pressure, look for any sign of pests, and make sure the battery maintainer is still doing its job. Catching a small problem in December is a lot cheaper than discovering it in spring.
Should I keep insurance on my RV while it’s stored?
Yes, keep comprehensive coverage active. Storage facilities are actually the most common place RVs get stolen, and comprehensive also covers fire, weather, and falling objects while the rig sits. What you can usually drop is collision and liability, since you’re not driving it, and suspending those often saves a good chunk while keeping the important protection in place. Remember that the facility’s own policy covers their building, not your RV.
