Storing your rig for the winter is more than just parking it under a cover and walking away. If you leave water in the lines or ignore your batteries, you are inviting a massive repair bill come springtime.
Learning how to winterise an rv is a fundamental skill that every owner must master to protect their investment. This guide provides a step-by-step roadmap to ensure your plumbing, electrical systems, and interior remain pristine during the deep freeze.
We will walk through the essential tools, the two primary methods of clearing water lines, and the often-overlooked maintenance tasks that keep rodents and mold at bay. Let’s get your rig ready for its winter nap.
Preparation and Essential Tools for the Job
Before you begin the process, you need to gather specific supplies that are unique to the RV world. Using the wrong materials, such as automotive antifreeze, can be a fatal mistake for your plumbing system and your health.
Automotive antifreeze is toxic and should never enter your freshwater system. Instead, you must use non-toxic, propylene glycol-based RV antifreeze, which is usually pink. This substance is designed to be safe for potable water lines.
You will also need a few hardware items to make the job easier. A water heater bypass kit is essential if your RV is not already equipped with one. This kit prevents you from wasting six to ten gallons of antifreeze by filling the heater tank unnecessarily.
Gather the following items before you start:
- Non-toxic RV antifreeze (usually 2-3 gallons).
- A water heater bypass kit (if not factory-installed).
- A blow-out plug for your city water inlet.
- An air compressor with adjustable pressure settings.
- A wand attachment for cleaning out the black tank.
- Basic hand tools, including a socket set for the water heater drain plug.
Having these tools ready will streamline the process and prevent you from having to run to the hardware store mid-way through. Proper preparation is the hallmark of an experienced DIYer.
Cleaning the Holding Tanks
You should never store an RV with waste sitting in the tanks. Residual solids can harden over the winter, creating a “pyramid” of waste that is nearly impossible to remove later. This can also damage your tank sensors.
Start by taking your rig to a proper dump station. Empty the black tank first, followed by the gray tank. The gray water helps flush the remaining debris from the sewer hose, keeping things relatively clean.
Use a tank rinser or a wand attachment to thoroughly clean the interior walls of the black tank. Continue rinsing until the water running through the clear elbow of your sewer hose is completely transparent.
Once the tanks are empty, add a small amount of tank treatment and about a gallon of water. This keeps the seals lubricated and prevents any remaining residue from drying out and becoming “concrete” on the tank floor.
Finally, ensure the valves are closed tightly. Inspect the termination caps for cracks. A leaky valve can lead to a very messy and unpleasant surprise when you de-winterise in the spring.
how to winterise an rv
The most critical stage of the process involves removing all water from the plumbing system to prevent pipes from bursting. Knowing how to winterise an rv requires choosing between the compressed air method or the antifreeze method.
Start by bypassing your water heater. Locate the back of the heater (usually behind a panel inside the rig) and turn the valves to the bypass position. This ensures the antifreeze goes into the lines rather than the tank.
Drain the water heater tank by removing the drain plug or the anode rod. Open the pressure relief valve on the top of the unit to allow the water to flow out faster. Be careful, as the water might still be hot if you recently used the rig.
Open all the low-point drains on the exterior of the RV. These are the lowest spots in your plumbing system. Open all faucets inside the rig, including the shower and the outdoor kitchen, to help gravity pull the water out.
Once the water stops dripping, close the faucets and the low-point drains. Now you are ready to introduce the pink stuff into the system using the internal water pump or a hand pump through the city water inlet.
Turn on the pump and open each faucet one by one, starting with the one closest to the pump. Run the water until you see a solid stream of bright pink liquid. Do not forget the toilet, the showerhead, and the outside shower port.
Finally, pour a cup of antifreeze into every P-trap (the U-shaped pipe under sinks). This prevents the water in the traps from freezing and cracking the plastic. It also blocks sewer gases from entering the living space during storage.
The Compressed Air Method (Blowing Out the Lines)
Some owners prefer to use compressed air instead of antifreeze for the main lines. This method is “cleaner” because you don’t have to flush out the pink taste in the spring, but it requires extreme caution regarding pressure.
Attach a blow-out plug to your city water inlet. Set your air compressor to no more than 30-40 PSI. Exceeding this pressure can blow the fittings right off your PEX tubing or damage the delicate seals in your faucets.
With the compressor running, open each faucet individually. You will hear a hiss of air followed by a mist of water. Keep the faucet open until only air comes out. Repeat this for every water outlet in the RV.
Do not forget the toilet valve. Step on the flush pedal until all water is cleared from the valve. This is a common failure point because a tiny amount of trapped water can crack the plastic valve housing easily.
Even if you use air for the lines, you must still use antifreeze for the P-traps and the waste tanks. Air cannot clear the water sitting in the “U” of the drain, and that water will freeze and break the pipe.
Many professional technicians recommend a “belt and suspenders” approach. They blow the lines out with air first and then follow up with antifreeze. This ensures there are no pockets of water left to cause trouble.
Interior Preservation and Pest Control
Winterising isn’t just about plumbing; it’s about protecting the interior from the elements and uninvited guests. Rodents love the insulation and upholstery inside a quiet, stationary RV during the cold months.
Remove all food items from the cabinets. Even dry goods like crackers or flour can attract mice. Clean the floors and counters thoroughly to remove any crumbs or sticky spills that might leave a scent trail.
Defrost your refrigerator and freezer. Prop the doors open using a specialized stay or a simple towel. If you close the doors, the trapped moisture will grow thick black mold within weeks, ruining the appliance.
Place moisture absorbers, like DampRid, in the middle of the cabin and the bathroom. These canisters pull humidity out of the air, preventing mildew from forming on your headliner and cushions during temperature swings.
To deter rodents, seal any gaps where pipes or wires enter the floor using stainless steel wool. Unlike spray foam, mice cannot chew through steel wool. You can also place peppermint oil-soaked cotton balls in the corners of cabinets.
Leave your closet doors and cabinet doors slightly ajar. This allows air to circulate throughout the unit. Stagnant air is the primary cause of that “musty” smell that often greets owners in the spring.
Exterior Maintenance and Roof Inspection
The exterior of your RV takes a beating from snow, ice, and UV rays during the winter. A small leak in a roof seal can become a catastrophic failure after a cycle of freezing and thawing.
Climb onto the roof (or use a ladder) and inspect every inch of the lap sealant. Look for cracks, peeling, or gaps around the vent fans, AC unit, and sky lights. Use a high-quality RV sealant to patch any suspicious areas.
Clean your awnings and ensure they are completely dry before retracting them for the season. If you roll up a wet awning, it will be covered in rot and mildew by the time the weather warms up.
Wash the exterior to remove road salt and grime. If you live in a coastal area or a place where they salt the roads, this is vital to prevent corrosion on the chassis and the aluminum siding.
Consider using a breathable RV cover. Avoid using a standard blue plastic tarp, as these trap moisture against the body of the rig and can cause “osmotic blistering” or paint damage. A breathable cover protects from UV while letting moisture escape.
Lubricate the slide-out seals with a silicone-based spray. This keeps the rubber supple and prevents it from sticking to the side of the RV or cracking in the extreme cold temperatures.
Battery Care and Electrical Systems
Batteries are expensive, and cold weather is their greatest enemy. A fully charged battery can survive freezing temperatures, but a discharged battery will freeze and burst its casing at 32 degrees Fahrenheit.
If you have lead-acid batteries, check the water levels and top them off with distilled water. Ensure they are fully charged before disconnecting them. If possible, remove the batteries and store them in a cool, dry place like a garage.
For those who leave their batteries in the rig, use a “trickle charger” or a battery tender. This keeps the voltage at an optimal level without overcharging. If you have a battery disconnect switch, make sure it is in the “off” position.
If your RV has a motor, such as a Class A or Class C, you need to treat the fuel. Add a high-quality fuel stabilizer to the gas tank and run the engine and the generator for 15-20 minutes to get the treated fuel into the lines.
Check your tire pressure. Tires naturally lose air in the cold, and “flat-spotting” can occur if they sit underinflated for months. Inflate them to the maximum recommended PSI and use tire covers to block UV damage.
If the rig will be parked on dirt or grass, pull the tires onto wooden planks or plastic pads. This prevents the rubber from absorbing moisture from the ground, which can lead to premature sidewall cracking and dry rot.
Frequently Asked Questions About how to winterise an rv
Can I use a hairdryer to thaw frozen pipes?
While you can use a hairdryer, it is a slow and potentially dangerous process if there is standing water. It is much better to prevent the freeze in the first place. If a pipe is already frozen, check for cracks immediately upon thawing.
How much antifreeze does a standard RV need?
Most travel trailers and fifth wheels require between 2 and 3 gallons of RV antifreeze. If you have a large motorhome with a washing machine and dishwasher, you may need 5 gallons or more to ensure all lines are flushed.
Do I really need to bypass the water heater?
Yes. If you don’t bypass it, you will have to fill the entire 6 or 10-gallon tank with antifreeze before it even reaches your hot water lines. This is a waste of money and makes it harder to rinse the tank in the spring.
Is it okay to leave the RV plugged into shore power all winter?
It is generally okay if your RV has a modern “multi-stage” converter that won’t boil the batteries dry. However, it is still wise to check the battery water levels once a month to ensure the charger is working correctly.
Should I leave my levelers or jacks down?
It is best to leave them down to stabilize the rig and take some weight off the tires. However, wipe the chrome shafts with a bit of lubricant or WD-40 to prevent rust and corrosion while they are extended in the elements.
Closing Thoughts for a Stress-Free Spring
Taking the time to learn how to winterise an rv is an investment in your future adventures. By following these steps, you ensure that your first trip of the next season starts with a campfire, not a call to a mobile mechanic.
Remember that every RV is slightly different. Always consult your owner’s manual for specific instructions regarding your model’s plumbing layout and electrical requirements. The goal is to be thorough and methodical.
Once the work is done, you can rest easy knowing your home-on-wheels is safe from the frost. Take a final walk-around, double-check your locks, and look forward to the thaw. Stay safe and stay comfortable!
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