Year-End RV Maintenance Checklist

RV Maintenance

Year-End RV Maintenance Checklist

December is when most RV owners park the rig for the winter and don't think about it again until April. That gap — four or five months of sitting in a driveway or storage lot — is where expensive problems develop. Water left in the plumbing freezes, cracks a fitting and causes a flood when you turn the pump on in spring. A battery drains down to nothing and sulfates beyond recovery. A mouse gets in through a gap you didn't seal and chews through a wire harness that costs $800 to replace.

Year-end maintenance takes four to six hours for a travel trailer or fifth wheel and a full day for a motorhome. The materials cost $50 to $150. Skipping it costs $500 to $5,000, depending on what fails. Those numbers aren't hypothetical. RV service centers report that 60% to 70% of spring repair appointments involve problems that proper winterization would have prevented.

This checklist covers every system in the rig, in the order you should work through them. Print it out, tape it to the refrigerator and check items off as you go.

Plumbing: The Number One Priority

Frozen plumbing is the most common and most expensive category of winter RV damage. Water expands roughly 9% when it freezes, and PEX tubing, ABS fittings and plastic valves all crack under that pressure. A single cracked fitting behind a wall can dump 40 gallons of water into the subfloor before you discover it.

Draining the System

Start by draining the fresh water tank. Open the low-point drain valves — most rigs have two, one for hot water lines and one for cold. They're usually located on the underside of the rig near the center. Let them run until the flow stops.

Open all faucets (both hot and cold positions) including the shower and any exterior shower or rinse station. Flush the toilet and hold the pedal down to drain the bowl. Open the water heater drain plug or anode rod to empty the 6- to 10-gallon tank. If your water heater has a bypass valve system, set it to bypass mode now — this prevents you from pumping 6 to 10 gallons of antifreeze into the heater tank later.

If your rig has an ice maker, washer/dryer hookups or an exterior kitchen with separate plumbing runs, those lines need to be addressed individually. Consult your owner's manual for the specific drain points.

Antifreeze Method

The "wet" winterization method — pumping non-toxic propylene glycol RV antifreeze through the plumbing — is the most reliable approach, especially for rigs stored in climates that regularly drop below 20°F.

You'll need 2 to 3 gallons of RV antifreeze for a travel trailer, 3 to 4 gallons for a fifth wheel and 4 to 6 gallons for a motorhome with multiple bathrooms. Buy the pink propylene glycol type. Never use automotive antifreeze (ethylene glycol) — it's toxic and will destroy rubber seals in your plumbing system.

The process:

Confirm the water heater bypass is set.
Connect the winterization kit suction tube (usually near the water pump) to the antifreeze jug. If your rig doesn't have a built-in winterization port, disconnect the inlet side of the water pump and run a tube from the pump directly into the jug.
Turn on the water pump.
Open the cold water faucet at the kitchen sink and let it run until pink antifreeze flows. Close it.
Open the hot water faucet at the kitchen sink. Wait for pink. Close it.
Repeat for every faucet, shower head and toilet in the rig.
Pour a cup of antifreeze down each drain to protect the P-traps.
Don't forget the exterior shower and city water inlet.

Compressed Air Method

The alternative is blowing out the lines with compressed air. This works well in combination with draining but carries a small risk of residual water remaining in low spots or complex valve assemblies that can still freeze.

Use a blowout plug (a brass fitting with a Schrader valve, about $8) connected to a compressor set to no more than 30 PSI. Higher pressure can damage PEX fittings. Open each faucet in sequence and blow until only air comes out. Then pour antifreeze down each drain for the P-traps regardless — the compressed air method doesn't protect drain traps.

Many experienced RV owners use both methods: blow out the lines first, then run a reduced amount of antifreeze through as insurance.

Roof Inspection and Sealing

The roof is the second most critical system to address before winter storage. Water intrusion through failed sealant joints is the leading cause of structural RV damage, and a roof that sits under rain, snow and ice for five months with a compromised seal will develop problems.

Inspection Process

Climb up on the roof (if your roof is rated walkable — check your owner's manual). Inspect every sealant joint methodically:

Around the air conditioning unit base
Around roof vents and fans
Around antennas and satellite dish mounts
Along the front and rear cap joints
Around any screw penetrations
Along the side-to-roof transition (the most common failure point)

What you're looking for: cracking, peeling, separation or gaps in the sealant. Press the sealant with your fingernail. If it's hard and brittle rather than flexible, it needs to be replaced.

Resealing

For self-leveling roof sealant (used on flat surfaces), Dicor 501LSW is the industry standard. Clean the old sealant area with Dicor Cleaner/Activator first — fresh Dicor won't bond properly to dirty or oxidized surfaces. Apply a generous bead that covers the old sealant plus a quarter-inch margin on each side.

For vertical surfaces and non-level joints, use Dicor non-sag sealant (551LSW). It holds its shape rather than flowing, which prevents drips on sidewalls.

One tube of Dicor covers approximately 20 linear feet. Most travel trailers need one to two tubes for a thorough touch-up. Cost: $12 to $15 per tube.

Important note: Do not use silicone sealant on an RV roof. Silicone doesn't bond to itself during future repairs and leaves a residue that prevents Dicor or other sealants from adhering. If a previous owner used silicone, you'll need to remove it completely before applying proper sealant — a miserable job that involves mineral spirits and a lot of patience.

Roof Cleaning

While you're up there, clean the roof. EPDM rubber roofs chalk over time, and the chalk buildup traps dirt and moisture. Use an EPDM-specific cleaner (not petroleum-based products, which damage the membrane) and a medium-bristle brush. Rinse thoroughly.

TPO roofs are easier to maintain — a mild soap and water wash is usually sufficient. Fiberglass roofs should be waxed with a marine or RV-specific wax after cleaning to protect the gel coat from UV degradation.

Battery Care and Storage

A dead battery in spring is annoying. A battery that froze and cracked over the winter — leaking acid inside your compartment — is dangerous and expensive. Proper winter battery storage prevents both outcomes.

Lead-Acid and AGM Batteries

A fully charged lead-acid battery freezes at approximately -80°F. A 50% discharged battery freezes at about 16°F. A fully discharged battery freezes at 32°F. The takeaway: a discharged battery in a northern climate will freeze and crack. Keep batteries charged.

For short-term storage (1-3 months): Charge the battery fully. Disconnect the negative cable to eliminate parasitic draws from the LP detector, radio memory and other always-on components. Check the charge level monthly and top up if it drops below 12.4V.

For long-term storage (4+ months): Remove the battery from the RV entirely. Store it in a cool, dry place (garage floor is fine despite the old myth about concrete draining batteries — it doesn't). Connect a maintenance charger or trickle charger rated for your battery type. A quality maintainer costs $30 to $50 and keeps the battery at optimal charge without overcharging.

For flooded lead-acid batteries, check the water level before storage. The plates should be fully submerged. Add distilled water only — never tap water. Wear eye protection. Battery acid is sulfuric acid.

Lithium (LiFePO4) Batteries

Lithium batteries require different winter care. Most LiFePO4 batteries have a built-in battery management system (BMS) that prevents charging below 32°F. This protects the cells from lithium plating, which causes permanent damage.

If your rig has lithium batteries and you're storing it in a location that drops below freezing, disconnect the charging source (solar panels, converter) to prevent the system from attempting to charge a cold battery. The BMS should handle this automatically, but disconnecting eliminates the variable.

Lithium batteries self-discharge much more slowly than lead-acid — typically 2% to 3% per month versus 5% to 15% per month. A fully charged lithium battery can sit for several months without maintenance charging in moderate climates.

Tire Care Before Storage

RV tires degrade from age, UV exposure and ozone more than from tread wear. Most RV tires should be replaced at 5 to 7 years regardless of how much tread remains.

Pre-Storage Steps

Inflate to maximum cold pressure listed on the tire sidewall (not the vehicle placard — the tire's maximum). Higher pressure during storage reduces flat-spotting, where the weight of the RV deforms the contact patch into a permanent flat area.

Cover the tires with UV-blocking tire covers ($30 to $60 for a set of four). UV radiation breaks down the rubber compounds that give tires their flexibility. A season of uncovered storage in direct sunlight does measurable damage.

If possible, park on plywood or plastic sheeting rather than directly on concrete or asphalt. Moisture wicks through concrete and accelerates rubber degradation on the contact surface.

Do not jack the RV and leave it on blocks to take weight off the tires unless you also support the frame at manufacturer-specified jack points. Improperly supported frames can twist, misaligning slides and doors.

Tire Inspection

Check each tire for:

Sidewall cracking (especially in the flex zone between the tread and the rim)
Bulges or blisters (indicating internal structural damage)
Uneven wear patterns (suggesting alignment issues or overloading)
Date code verification (DOT code, last four digits = week and year of manufacture)

Any tire showing deep sidewall cracks or bulges should be replaced before the rig moves again. This is a safety issue. Blowouts at highway speed on a travel trailer cause loss of control. They damage the wheel well, underbelly panels and sometimes the frame.

Appliance Servicing

Refrigerator

Absorption refrigerators (the type in most RVs, made by Dometic or Norcold) need specific attention before storage.

Empty and clean the interior. Prop the doors open — both the fridge and freezer sections. Closed doors on an empty, unpowered refrigerator breed mold within days.

Clean the burner assembly on the outside of the rig. Remove the exterior access panel and inspect the burner tube for rust, spider webs and debris. A can of compressed air clears the tube. A clogged burner tube is the most common cause of "my fridge won't cool on gas" calls in the spring.

Check the flue (the vertical chimney above the burner) for blockage. Wasp nests are common in this space.

Water Heater

If you didn't already drain it during winterization, do it now. Remove the anode rod (on Suburban models) or the drain plug (on Atwood/Dometic models).

Inspect the anode rod. If more than 75% of the rod is consumed (it looks like a thin, pitted stick rather than a solid cylinder), replace it. A new anode rod costs $10 to $15 and takes five minutes to install. Skipping this eventually corrodes the tank itself, turning a $15 maintenance item into a $350 to $500 water heater replacement.

Flush the tank with fresh water to remove sediment. A wand attachment ($15) connects to a garden hose and reaches inside the tank to break up mineral deposits.

Furnace

Clean the intake and exhaust vents on the exterior of the RV. Mud dauber wasps and spiders love these openings. A blocked exhaust vent causes carbon monoxide to back up into the living space. A blocked intake vent causes the furnace to burn inefficiently or not at all.

Run the furnace for 10 to 15 minutes to burn off dust before shutdown. This prevents the "burning smell" on first startup in spring and confirms the unit is functioning before you seal up the rig.

Check the furnace filter if your model has one (not all RV furnaces do). Replace it if dirty.

Air Conditioner

Clean the condenser coils on the rooftop unit and the evaporator coils inside the ceiling assembly. Bent cooling fins restrict airflow; use a fin comb ($8) to straighten them.

Check the foam gasket between the AC unit and the roof. Compression and UV exposure degrade this gasket over time, and a failed gasket allows water to leak around the AC directly into the ceiling — one of the hardest leaks to trace and repair.

Cover the rooftop unit with an AC cover ($25 to $40) to protect it from ice, snow and UV during storage.

Safety Systems Check

Smoke, CO and LP Detectors

These devices have finite lifespans that are independent of battery condition.

Smoke detectors: Replace every 10 years. Check the manufacturing date on the back of the unit.
Carbon monoxide detectors: Replace every 5 to 7 years. An expired CO sensor that still beeps when you press the test button may not actually detect carbon monoxide. The test button only confirms the alarm circuit works, not the sensor.
LP (propane) gas detectors: Replace every 5 to 7 years. Located near the floor because propane is heavier than air.

Replace batteries in all detectors even if the existing batteries test fine. Fresh batteries through the winter ensure the detectors function if you visit the rig mid-season or if a problem develops during storage.

Fire Extinguishers

Check the gauge. If it's in the red zone or if the extinguisher is more than 12 years old, replace it. A new ABC-rated fire extinguisher costs $20 to $30. An RV fire that could have been stopped with a working extinguisher is a total loss — the materials burn fast and hot.

Exterior Protection

Wash and Wax

Wash the exterior thoroughly before storage. Road grime, bug residue and bird droppings left on fiberglass or aluminum siding for months will etch into the surface.

Wax fiberglass sidewalls with a marine or RV-specific wax. This adds a UV barrier and makes spring cleaning dramatically easier. Aluminum siding doesn't need wax but benefits from a wash and a coat of aluminum protectant.

Seal Exterior Openings

Mice can enter through openings as small as a dime. Inspect every potential entry point:

Around plumbing pipes where they enter the underside of the rig
Around the furnace intake and exhaust
Around slide-out mechanisms
At the corners of compartment doors where weather stripping has compressed

Fill gaps with steel wool or copper mesh stuffed into the opening and sealed with expanding foam. Steel wool alone will rust and disintegrate. Copper mesh lasts longer. Expanding foam alone is a snack for mice — they chew right through it unless there's mesh behind it.

Peppermint oil on cotton balls placed inside compartments and under the rig acts as a deterrent but is not a permanent solution. Reapplication is necessary monthly.

Mothballs are effective but toxic to pets and children, and they leave a smell that takes weeks to dissipate. Use them only in enclosed compartments that can be aired out before the next trip.

RV Cover

Opinions on RV covers split the RV community. Proponents argue they protect against UV, rain and debris. Opponents argue they trap moisture, abrade the finish in wind and are a nightmare to install and remove.

The middle ground: if you're storing the rig outdoors in a sunny climate (Arizona, Texas), a cover provides genuine UV protection. If you're storing in a wet climate (Pacific Northwest, Southeast), moisture trapping is a real concern, and a covered or enclosed storage facility is a better investment than a fabric cover.

If you use a cover, ensure it's breathable (polypropylene or multi-layer fabric, not polyethylene tarps) and secured against wind. A cover that flaps in the wind will sand the finish off your rig.

Interior Prep

Remove all food. Everything. Canned goods are fine in above-freezing storage, but anything in the pantry that a mouse might find interesting (crackers, cereal, rice, flour) needs to leave the RV. Mice will find it. They always find it.

Clean all surfaces including inside cabinets, under cushions and behind appliances. Crumbs attract pests.

Leave cabinet doors and drawers open to promote air circulation and prevent musty smells.

Place moisture absorbers (DampRid or similar calcium chloride products) in the main living area, the bedroom and the bathroom. Check and replace them midway through the storage period if you can access the rig.

Set the thermostat to the lowest setting (or off if the rig will be completely winterized). If you're storing in a location where temperatures fluctuate around freezing and you've opted not to fully winterize the plumbing, leave the heat set to 40°F. This uses propane but prevents freezing. Confirm you have adequate propane supply and that the regulator is functioning.

RV Maintenance