Before the First Freeze: A Practical Guide to Winterizing Your RV in Helena, MT

An RV that sits through winter without proper preparation can develop problems that aren't obvious until the next camping season. Water left in plumbing lines can freeze and damage fittings, batteries can lose their charge, and moisture trapped inside the living area can cause trouble long after the vehicle has been parked. Knowing how to winterize an RV for storage helps you address those problems before they turn into expensive repairs.

For RV owners around Helena, preparing for freezing temperatures is an important part of putting a camper away for the season. At Helena Security Storage, we offer covered and uncovered RV parking for people who need room outside their driveway or garage. Our storage options in Helena, MT include vehicle parking with month-to-month rentals, so you can arrange a space that fits your plans for the offseason.

When Should You Winterize Your RV?

The best time to winterize an RV is before temperatures drop below freezing, particularly if the vehicle won't be heated or used regularly. Water trapped inside pipes, pumps, valves, and fixtures can expand as it freezes, potentially cracking components that are difficult to inspect or replace. You don't need to wait until you're officially finished camping for the year. If your RV will sit unused during a period of freezing temperatures, its water system needs protection. This applies to motorhomes, travel trailers, and fifth wheels, though the exact winterization procedure depends on the model and its plumbing equipment. Start by reviewing your owner's manual. Some RVs have built-in winterization valves, while others require additional fittings or a different procedure. The manual also identifies equipment that needs special attention, including water heaters, filtration systems, and appliances connected to the water supply.

Step 1: Drain the RV's Water System

Plumbing is the most important place to start because even a small amount of trapped water can cause damage during freezing conditions. Before draining anything, turn off the water heater and allow the water to cool. Disconnect the RV from its external water supply and turn off the water pump. Open the faucets to release pressure, then locate the low-point drains and fresh water tank drain. These openings allow water to leave the plumbing system, though draining alone doesn't necessarily remove everything trapped in fittings, valves, and appliances.

Empty the Fresh Water and Holding Tanks

Drain the fresh water tank completely, following the procedure for your RV. The gray and black holding tanks should be emptied at an approved RV dump station before the vehicle goes into storage. If the waste tanks need flushing, complete that process while the plumbing is still operational.

Pay attention to the water heater. Traditional tank-style heaters usually have a drain plug or anode rod that must be removed after the heater is turned off, depressurized, and cooled. Tankless systems have different procedures, so follow the equipment manufacturer's instructions rather than assuming the same steps apply.

Don't Forget the Smaller Water Connections

Outdoor showers, refrigerator water dispensers, washing machine hookups, and other accessories can hold water after the main tanks have drained. Check which features your RV actually has and follow the winterization instructions for each one. A common mistake is to finish the main plumbing system while overlooking an outside shower or a water line serving an appliance. Those smaller connections are still vulnerable to freezing, even when the rest of the system has been prepared.

Step 2: Protect the Plumbing With RV Antifreeze

Once the system has been drained, many RV owners use antifreeze designed specifically for recreational vehicle plumbing. This is different from automotive engine antifreeze, which must never be introduced into the RV's drinking water system. The exact process depends on your RV's configuration. Some vehicles have a winterization inlet or siphon hose that allows the water pump to draw antifreeze directly from its container. Others require a separate winterization kit. Before introducing antifreeze, check the water heater bypass arrangement. Most tank-style water heaters should be bypassed so antifreeze doesn't fill the heater tank. Filters and other equipment may also need to be removed or bypassed according to the manufacturer's instructions.

With the system configured correctly, the usual procedure is to run RV-approved antifreeze through the hot and cold plumbing lines until it appears at the appropriate fixtures. This includes the toilet and any exterior water connections that are part of the system. Drain traps and toilet seals also require protection. 

Can You Winterize an RV Without Antifreeze?

Some RVs can be winterized using compressed air to remove water from the plumbing lines. This method requires a suitable adapter, regulated air pressure, and careful attention to every water connection. The difficulty is that compressed air doesn't necessarily remove water from every pump, trap, appliance, or low point. Certain components still require additional treatment, and excessive air pressure can damage plumbing. If you're unfamiliar with your RV's water system, having a qualified RV technician perform the winterization is a reasonable choice. The cost of professional service may be considerably less than repairing a cracked water line or damaged water heater.

Step 3: Prepare the Battery and Electrical System

An RV battery can gradually discharge while the vehicle sits unused. Some onboard electronics continue drawing power even when the RV appears to be switched off, so simply parking the vehicle doesn't guarantee that the battery will maintain its charge. Start by fully charging the batteries and checking their condition. If your RV has a battery disconnect switch, follow the manufacturer's instructions for using it during storage. Keep in mind that some electrical components may remain connected even when the disconnect is activated.

For extended winter storage, battery removal may be appropriate if the manufacturer permits it. Store removable batteries in a suitable location and maintain their charge with equipment designed for that battery chemistry. Lithium batteries, in particular, have charging temperature restrictions that differ from those of conventional lead-acid batteries. If your RV has solar panels or another charging system, verify how it interacts with the battery disconnect and charge controller. Don't assume the system will maintain the battery correctly without checking its operating requirements.

Step 4: Check the Tires Before Parking

RV tires support substantial weight, and prolonged parking places continued pressure on the same contact areas. Before storage, inspect the tires for cracking, uneven wear, embedded objects, and other visible damage. Inflate them according to the RV or tire manufacturer's recommendations for the vehicle's weight and tire configuration. The maximum pressure printed on a tire's sidewall isn't automatically the correct operating pressure for every RV.

Choose a reasonably level parking position and follow the manufacturer's guidance for parking brakes, wheel chocks, and stabilizing equipment. Trailer owners should also inspect the hitch, safety chains, and related components before putting the vehicle away. If the RV will remain parked for several months, consider how you'll inspect tire condition and pressure during storage. Any tire supports or protective accessories should be appropriate for the vehicle and used according to their instructions.

Step 5: Clean the Interior and Remove Food

Before closing the RV for winter, remove food from the refrigerator, cabinets, and storage compartments. Even sealed packages can attract pests if they contain food residue or have damaged packaging. Empty the refrigerator and freezer, clean the interior surfaces, and allow everything to dry. Follow the appliance instructions for leaving the doors positioned to prevent trapped moisture while the refrigerator is switched off. Clean cooking surfaces, wipe down counters, and remove trash. Vacuuming beneath seats and around cabinets is worthwhile because crumbs collect in areas that aren't always visible during routine cleaning. Bedding, towels, and other fabrics should be completely dry before storage. Remove damp items rather than leaving them in closed compartments for several months.

Reduce Moisture Inside the RV

Moisture can become trapped inside an RV when it is closed for an extended period. Check around windows, roof openings, and plumbing fixtures for signs of leaks before parking. Clean and dry the bathroom, shower, and kitchen sink. If you use a moisture absorber, select one appropriate for an unattended RV and place it where accidental spills won't damage surrounding materials. Ventilation needs vary by RV design. Some vehicles have protected vents intended for limited airflow, while others require vents and openings to remain closed during storage. Follow the manufacturer's recommendations rather than leaving a roof vent open without confirming that it is suitable for winter conditions.

Step 6: Inspect the Roof, Seals, and Exterior

The RV's exterior deserves attention before it spends several months parked. Inspect the roof membrane, sealant around roof penetrations, window seals, and exterior compartment doors for visible deterioration. Look closely at areas surrounding antennas, vents, and other roof-mounted equipment. Damaged sealant should be repaired using products approved for the RV's roof material. Applying an incompatible sealant can create additional problems instead of correcting a leak.

Wash the exterior to remove accumulated dirt and road residue, then let it dry. Clean the awning according to its manufacturer's instructions and make sure the fabric is dry before retracting it. Retract slide-outs as directed by the RV manufacturer and inspect the seals for damage or debris. Secure exterior storage compartments, windows, and access panels before leaving the vehicle.

Should You Use an RV Cover?

An RV cover can provide additional protection while the vehicle is parked outdoors, but the cover must be designed for the RV's dimensions and configuration. Poorly fitted covers can rub against exterior surfaces or become damaged by wind. Choose a breathable product intended for RV storage rather than an ordinary plastic tarp. Secure it according to the cover manufacturer's instructions, paying particular attention to roof accessories and sharp edges. Covered parking is another option for owners who want overhead protection without placing a full cover over the vehicle. It reduces direct exposure to precipitation and sunlight, though the RV's sides remain exposed to outdoor conditions.

Step 7: Prepare the Engine, Fuel, and Propane Systems

Motorhomes require additional attention because their engines and chassis systems will remain inactive during storage. Follow the chassis manufacturer's instructions for engine oil, coolant, fuel, and other maintenance items. For gasoline-powered vehicles, fuel stabilizer may be appropriate when recommended for the engine and fuel system. Use the correct product and follow its instructions. Diesel-powered motorhomes have different fuel storage considerations, including fuel quality and cold-temperature operation.

Check the engine coolant's freeze protection using the method specified for your vehicle. The antifreeze used in an engine cooling system is separate from the RV plumbing antifreeze discussed earlier. Propane systems also need to be secured before storage. Turn off the supply according to the RV manufacturer's instructions and confirm that propane appliances are shut down. If you suspect a leak or notice damaged fittings, arrange professional inspection rather than attempting an improvised repair.

Step 8: Choose the Right RV Storage Space in Helena

After winterizing the vehicle, consider where it will remain parked. At Helena Security Storage, we offer covered and uncovered outdoor parking for RVs, campers, and trailers. Our facility is located at 3425 Allied Drive, along the Highway 12 corridor between downtown Helena and East Helena. Covered parking provides overhead protection from direct precipitation and sunlight. Uncovered parking is another option for RV owners who have prepared their vehicles for outdoor storage. Neither option replaces proper winterization, particularly the steps needed to protect the plumbing and batteries.

Before selecting a parking space, measure the full length and height of your RV. Include the hitch, rear-mounted accessories, roof equipment, and anything else that affects its overall dimensions. Available parking space sizes can change, so it's worth confirming the current options before arranging storage. Our property is fenced and gated, with keypad entry and security cameras. Renters have access daily from 7:00 AM to 10:00 PM, which allows time for periodic vehicle inspections during the storage season. We also offer month-to-month rentals. If you're uncertain when your next trip will begin, our guide to flexible month-to-month storage explains how that rental arrangement works.

Step 9: Check Your RV During Winter Storage

Winterization is completed before parking, but it's worth checking the RV periodically while it remains in storage. Look for visible roof damage, loose exterior covers, tire problems, and signs of moisture around windows or doors. Inspect the battery according to your maintenance plan and check for evidence of pests inside accessible compartments. If you've used moisture-absorbing products, inspect them and replace or empty them as directed.

Avoid starting a motorhome engine briefly just to let it idle unless the chassis manufacturer recommends that procedure. Short periods of idling may not bring the engine and related systems to proper operating temperatures. Keep a record of the winterization work you've completed, including any components that were drained, disconnected, or bypassed. That information will be useful when it's time to return the RV to service.

Getting Your RV Ready for Spring

When camping season approaches, reverse the winterization procedure according to your RV's manual. Flush the plumbing system, restore the water heater to its operating configuration, and sanitize the fresh water system as instructed by the manufacturer. Reconnect and charge batteries as needed, check the tires, and inspect the roof and exterior seals. Test the water system for leaks before loading the RV for a trip. Motorhomes should also receive the appropriate engine and chassis checks before returning to the road. If you've removed camping accessories, hoses, or other equipment during winterization, inspect those items before putting them back into service. Our packing and organization tips for stored belongings can also help if you're keeping seasonal camping gear in a separate unit.

Keep Your RV Ready for the Next Camping Season

Learning how to winterize an RV for storage is largely about knowing which systems need attention before freezing temperatures arrive. The plumbing requires the most careful preparation, but battery maintenance, moisture prevention, tire inspections, and exterior repairs all deserve a place in your offseason routine. Once the vehicle is properly prepared, the next decision is finding a parking space that accommodates its dimensions and your expected storage period. At Helena Security Storage, our covered and uncovered parking options support seasonal RV storage, with daily access for owners who need to check on their vehicles. For RV owners planning where to keep their camper between trips, it's possible to explore storage options from Helena Security Storage and review current parking availability before the vehicle is ready to be put away.