With Old Man Winter lurking just around the corner, make sure you prepare your RV correctly and completely before the freezing temperatures arrive.
By Gary Bunzer
September 2003
You feel it, don’t you? That little nip in the evening air. The trees look a little less leafy than last week. Shorter days and cooler nights are surefire indicators that another camping season is coming to a close. Of course, some full-time RVers will head to warmer climes for the late fall and winter. If you’re not one of those fortunate souls, the pressing thought once the weather turns chilly becomes “time to winterize the motorhome.”
Not a problem, you say; been there, done that. Except for that time you forgot to fully drain the water heater and you had to purchase a new unit before its time. And remember when the engine battery froze during that one unexpected cold snap? Yep, and what about the year the fresh water hose was stowed away with water still in it? Forgot about those little instances, huh?
The truth is, it’s quite easy to forget to do something when winterizing and storing a motorhome. Unless you take a systematic approach to winterizing your RV, Mother Nature is sure to catch any faux pas and turn a seemingly insignificant oversight into a major repair. What follows is a sequence of procedures that will help you prepare your motorhome for any deep drop in the thermometer over the course of your winter downtime. For best results, perform these steps in the order presented. If you’re ready, empty out the refrigerator, block out the day, and let’s get started.
Exterior
Start with a clean motorhome. Be sure to remove all debris, road grime, dirt, and tree sap from the exterior of the coach. Keep in mind that those dead bugs on the front cap and the bird droppings on the rubber roof contain acids that could damage your motorhome’s finish or stain the EPDM rubber membrane. Examine the exterior of the coach now and make any needed repairs. Closely inspect the sealants around roof accessories such as vents, antennas, skylights, storage racks, etc., plus all windows and doors. Reseal where necessary to avoid a magnified problem next spring.
If your refrigerator roof vent does not have a protective screen under the lid, install a piece of 1/4-inch chicken wire or aluminum wire mesh over the opening to prevent birds and other critters from nesting on the evaporator coils. Keeping this area clean could preclude an overheated refrigerator during that first trip in the spring.
Clean away all debris from the rooftop air conditioner(s). An air conditioner cover is a good investment for each rooftop unit, but do not wrap the units in plastic. This will only trap moisture. A good air conditioner cover will breathe while it protects.
Roll out the patio awning, window and door awnings, and any awnings attached to slideout rooms. Sweep away tree branches, leaves, and dirt; wash both the tops and bottoms of the awnings; and ensure they are completely dry before rolling them up. Eliminating dirt and moisture will stop the proliferation of mildew on the awnings. Spray a light coat of a silicone-based lubricant on all the metal moving parts.
Once you’re finished on top, if your roof is rubber, apply a thin coat of rubber roof protectant over the entire roof.
Slideout room preparation is easily accomplished by extending each room and wiping down all of the exposed hydraulic or electric slide components. Though a well-supported slideout may be left “out” over the winter with minimal concern, it is advisable to periodically run the room in and out a few times every month if the motorhome will be idle for a long time. This will keep the jack rods and internal seals lubricated. Most owners, however, choose to stow the motorhome with the slideouts in the travel position. I prefer doing this, because less surface area is exposed. Even if you leave the slideout closed, it’s still a good idea to run the room in and out a couple of times during the winter if possible.
Rust, moisture, and mild corrosion on mechanical gears and components can be eliminated by using a dry lube protectant such as the one produced by Protect All. A dry lube works best, since it will not attract dirt and other airborne contaminants while it displaces moisture.
Give some attention to the exterior rubber seals around each slideout room also. If the seals appear dirty and grimy, clean them first by using a rubber roof cleaning agent. After cleaning and drying, spray a bead of Protect All’s Slide-Out Rubber Seal Treatment, or a similar product, along each exposed seal. Evenly spread the protectant with a clean rag and allow all the seals to air dry. The treatment includes UV protectants along with water repellents to keep the seals soft and pliable and less prone to oxidation during the storage period.
Tires should be protected by covers. Aftermarket fabric covers are available, or you can simply use cut-out sections of plywood to block the UV rays of the sun. If you choose to use a tire protectant solution, be sure that it does not contain silicone, alcohol, or any petroleum-based additives, as they can cause a chemical reaction that will be harmful to the RV tires, rather than helpful.
Remove the coach’s weight from the tires by placing the axles on jack stands or blocks strong enough to support the weight safely. Another option is to reposition the coach from time to time by driving it for a minimum of 15 minutes to evenly distribute the dead weight on the tire sidewalls. Lowering the motorhome onto support stands (stack jacks) by letting air out of the air suspension is also a good plan if you cannot move the coach periodically. Reduce the air pressure only if you have a compressor available to pump air back into the air bags come spring.
To winterize the generator, remove the spark plugs. Squirt a dab of rust inhibitor into the cylinders and reinstall the plugs finger tight. Clean dirt and grime from all components. Follow the instructions listed in the generator owners manual for more specific winterizing procedures. If your coach is equipped with a diesel generator, skip this step. Just make sure the fuel tank is topped off before storage.
Visually inspect the entire undercarriage of your motorhome. Look for obvious damage, and for any small cracks, separations, or openings into the storage bays or motorhome. Mice and other rodents can squeeze through the smallest of openings. It is best to cover any such spaces with sheets of aluminum cut to fit.
Because of the complexity and variables associated with gasoline and diesel engines, radiators, transmissions, etc., as they relate to moisture and freezing temperatures, consult your manufacturer’s specific recommendations for winter storage. Most will recommend that the fuel tank be topped off to minimize the accumulation of moisture in the fuel system and that a fuel stabilizer be added.
Obviously, other automotive-related fluids and coolant tanks, windshield washer containers, etc., should be protected to the anticipated temperature level during the winter storage period, so check your manual for the specifics on your coach.
Fresh Water System
Freeze damage is the thing to avoid here. Freezing water expands, which can rupture tubing, fittings, and tanks. When winterizing the water system, you have two basic methods from which to choose “” wet or dry.
The wet method uses a nontoxic RV antifreeze to replace the water throughout most of the system. The dry method simply involves removing all moisture from the components. I feel it is important to keep seals in the system from drying out, so I favor the wet method. But I’m sure there are instances when the dry method is better. The point is, do what is best for your specific situation.
No matter which method you choose, start by draining the water heater, the fresh water storage tank, and all the hot and cold water lines in the system. Most RVs will have a low-point water valve for both the hot and cold lines somewhere in the motorhome. Check your owners manual for their location. Some valves may be inside a storage compartment, under an interior cabinet, or simply mounted below the floor under the motorhome.
All water heaters have a pressure and temperature relief valve along with a drain plug or valve located on the exterior of the water heater. Open both the relief valve and drain plug or valve and allow the water to completely drain. Forget those old wives’ tales about ruining the relief valve should you open it. The valve will not be damaged.
After the water heater has fully drained, reinstall the plug (or close the drain valve) and snap the pressure and temperature relief valve shut to keep unwanted critters from entering the tank. If your water heater is not equipped with a set of bypass valves that allow it to be isolated from the rest of the fresh water system, invest in them now. They attach to the rear of the heater and can be installed by anyone with a little mechanical know-how. If you opt for the wet method of winterizing, bypass valves are a must.
To ensure that all the water has been removed from the fresh water system, a blowout plug can be attached to the city water inlet and air pressure forced through the system to expel the water. Avoid using compressed air at service stations, because most will contain contaminants not conducive to fresh water piping. And, to avoid damage to any components or fittings, be sure to use less than 100 psi to drive any remaining moisture from the system. While you have the blowout plug handy, attach it to your water hose or other hoses you carry in your motorhome and purge the water from those coils.
Don’t overlook those easily forgotten portions of the fresh water system: ice maker tubing, washer inlet hose, shower hose, water purifier, toilet vacuum breaker, etc. All moisture must be removed. Keep in mind what Mother Nature can and will do should you leave some water in these components.
If you choose the wet method, it is not necessary to completely blow out the lines, but you will have to choose one of two techniques to add antifreeze. Before you start, make sure you are using a nontoxic, RV-approved antifreeze. Some RVers opt to pour several gallons of the antifreeze into the empty fresh water tank and simply pump the liquid through the entire system using the onboard water pump. This method protects the pump and filter/strainer on the suction side of the system as well. When the antifreeze solution appears at all hot and cold faucets, you’re done. If you have outside faucets in a compartment, don’t forget to run antifreeze through them also. All the lines will be filled except the water heater itself “” remember those bypass valves you just installed? Larger motorhomes with longer plumbing lines may require more antifreeze.
Be sure to flush the toilet until antifreeze appears in the bowl. Internal hoses and the vacuum breaker assembly mentioned earlier also must be protected. It’s easy to forget about these areas until you find water dripping behind the toilet during your first trip next spring.
Some high-end coaches come equipped with a separate antifreeze container and a set of valves already in place that will automate the winterizing process. If you are a serious RVer and store your motorhome in a frigid region of the country each year, it may be a wise investment to add this feature for future winters.
The other technique for adding antifreeze is to use a hand pump to backfill the solution through the kitchen or lavatory faucet. This method is more cumbersome and takes more time, yet it is less expensive. The goal of using the wet method is to fill all the lines with the protective liquid. However, when backfilling the system, only those lines and components downstream of the water pump are protected. The solution will stop at the outlet side of the pump at the integral backflow preventer. You still will need to protect the pump itself along with all the tubing on the suction side between the pump and the storage tank. This section is easy to overlook when using the backfill method.
Waste System
Begin by flushing and cleaning the holding tanks. This step can be integrated along with the procedures performed on the fresh water system. Whatever comes through the fresh system ultimately ends up in the holding tanks anyway. I always recommend leaving a shallow depth of water and antifreeze mixture in the holding tanks to help keep the seals moist at the termination valves.
If you have neglected the termination valves for some years or if you have noticed any dripping from around the valves in recent months, it is a good idea to remove, disassemble, clean, and lubricate each valve while the tanks are empty. Replacement seals are readily available at many RV parts stores. Although replacing the seals is not a truly appealing procedure, it will guarantee a leak-free and well-operating valve assembly in the spring. Take the time to do the unpleasant tasks now rather than in the spring when your only thoughts are about packing up and heading out. Admit it; you’ll never do it then.
If you opt not to take apart the termination valves now, at the very least spray a lubricant such as WD-40 in and around the slide valves. Or, better yet, add some drain valve lubricant product to each tank. To keep your tanks from leaking, you must keep those seals moist.
After the tanks have been flushed and cleaned and each has a slight amount of RV antifreeze at the bottom, pour an additional cup of RV antifreeze down each “P” trap to keep the water lock on the tank vapors. Do not overlook the shower drain or the washing machine trap if your coach is so equipped.
LP-Gas System
First and foremost, be sure all appliances are turned off completely, then close the outlet valve on the LP-gas tank. I recommend removing the regulator altogether and storing it separately in a clean, dry location or at least sealing it inside a plastic bag. This is done to keep dirt, dust, or moisture from getting into the vent portion of the device. Left-handed POL (Prest-O-Lite) and standard flare plugs and caps are available to block off the remaining openings in the hose and valve. Left-handed POL plugs also will fit into the newer Type 1 ACME valve. Also make sure to disable any LP-gas detectors.
Once you’ve finished closing off the LP-gas system, turn your attention to the appliances that use the fuel to operate. At the rear of the refrigerator, fashion a piece of cardboard the exact size as the door opening. Tape this cardboard to the inside portion of the door to keep dust and dirt from accumulating. Do the same thing at the water heater door.
Be sure to remove every trace of food from the refrigerator and freezer. Wash down the interior walls with a mild detergent; place an open box of baking soda or other absorbent inside; and block the doors slightly ajar.
Cover the fresh air inlet and the exhaust port of the furnace with duct tape or aluminum foil. Besides keeping mud daubers or other flying insects from building their nests there, it will help to keep the combustion chamber as clean as possible.
Since the typical LP-gas range itself is not vented to the exterior of the motorhome, there’s not much to do on it. Just make sure the oven and burners are clean and that the thermostat is turned off completely. Close any separate pilot valves if so equipped.
Batteries
If possible, even though it’s cumbersome, remove all the house batteries from the motorhome and store them in a clean, dry location. If this is not possible, at the very least disconnect and clean each terminal and spray it with a battery terminal protectant or coat it with a light petroleum jelly. Fully charge each battery to reduce the water content of the electrolyte. Keep in mind that a fully charged battery will freeze only if the temperature dips to 55 or 60 degrees Fahrenheit below zero, while a discharged battery may freeze at or near 20 degrees above zero.
To eliminate the possibility of a quick self-discharge, be sure the batteries are clean, dry, and free of dirt and acid buildup. Batteries will self-discharge over time; however, a clean and dry battery will self-discharge at a much slower rate. Battery sulfation also should be kept to a minimum. The best scenario is to recharge the battery from time to time during a long storage period. To avoid the risk of overcharging, do not leave the motorhome plugged in to shore power.
Remove all dry-cell batteries from clocks, radios, and flashlights, as well as smoke, LP-gas, and carbon monoxide detectors.
120-Volt AC System
Begin by unplugging all 120-volt AC appliances that you can get to, such as lamps, refrigerator, inverter, convertor, washer-dryer, microwave, etc. I also suggest that you turn off the main breakers at the breaker panel. This will protect the electrical system from being damaged by lightning that may strike at or near the RV (it does happen “” and it can be costly).
Clean and brighten the contacts on the shoreline cord and cover the plug end with a small plastic bag to minimize corrosion. If you are expecting high levels of moisture, an alternative is to use a shop towel instead of a plastic bag. All electrical connections benefit from environments that are clean, dry, and tight. Your efforts will pay off during that first excursion in the spring.
Miscellaneous Machinations
Clean the interior thoroughly. To keep mice from being attracted to your dormant RV, remove all remnants of food, including pet food. Vacuum under the cabinets and under the bottom drawers. Remove canned goods and all personal items if they contain liquids that may freeze.
To deter prying eyes and to prohibit the sun from fading fabrics, block out each window with cardboard or aluminum foil. For the serious RVer, however, a better alternative may be to invest in a total coach cover. Custom covers can be manufactured for those “not so common” motorhome profiles. A good cover is constructed of fabric that breathes as the weather conditions change.
When possible, remove heavy accumulations of snow from the roof if the coach is left outdoors uncovered and keep snowdrifts well below the bottom of the vehicle on all four sides.
Keep in mind that these procedures are quite generic in nature. Your particular RV may need more or less care depending on the accoutrements onboard. For best results, however, compare this advice with that published in your owners manual and take the necessary precautions. If your coach is preowned and came with no literature, this may well serve you as a primer for safe winter storage.
Now that your motorhome’s ready for a long winter’s nap, warm up that hot chocolate and settle back into your easy chair by the fire. We’ll touch base in the spring with a few tips for getting the RV ready for another season.
Technical consultant Gary Bunzer has written articles, presented educational seminars, and produced broadcast-quality videotapes for both the trade and consumer sides of the RV industry for more than 27 years. His video “Storing and Using Your Recreational Vehicle” is designed specifically for the RV owner. It visually details many of the winterizing steps discussed in this article, including the correct use of RV antifreeze.
For information about ordering this video, send a stamped, self-addressed, business-size envelope to Gary Bunzer, P.O. Box 2074, El Cajon, CA 92021. FMCA members will receive a 10 percent discount by mentioning that they read about the video in this article.
Winterizing Checklist
Exterior
Thoroughly clean the exterior
Examine the exterior and make needed repairs
Inspect sealants around the roof accessories
Make sure vents have protective screens
Remove debris from the rooftop air conditioner(s); add covers
Clean awnings
Apply rubber roof protectant if applicable
Lubricate all metal mechanical components on awnings and slideouts
Wipe down all exposed hydraulic/electrical components on slideouts
Open and close slideouts several times during the winter
Clean, dry, and apply a rubber seal treatment to all slideout seals
Protect tires with covers
Remove spark plugs from the generator; apply a rust inhibitor into the
cylinders; and reinstall plugs
Clean all dirt and grime off the generator components
Inspect the undercarriage and patch any cracks, separations, or
openings into the storage bays
Follow the manufacturer’s suggested winterizing procedures for fluids, tanks, etc.
Fresh Water System
Drain the water heater; reinstall the drain plug and snap the pressure and temperature relief valve shut
Drain the fresh water tank
Drain the hot and cold water lines
Select the wet or dry method of winterizing the fresh water system
Dry Method
Remove all moisture from the entire system, including the ice maker tubing, washer inlet hose, shower hose, water purifier, toilet vacuum breaker, etc.
Wet Method
Add nontoxic RV antifreeze to the fresh water tank and use the onboard water pump (or a hand pump to backfill antifreeze through a kitchen or lavatory faucet) to distribute the antifreeze throughout the entire system; run all faucets and flush the toilet until antifreeze appears
Waste System
Flush and clean the holding tanks
Remove, disassemble, clean, and lubricate each termination valve, if necessary
Inspect and replace bad seals
Leave a shallow depth of water and antifreeze mixture in the holding tanks
Pour antifreeze down the “P” traps
LP-Gas System
Turn off all appliances and LP-gas detectors
Close the LP-gas tank outlet valve
Remove and store the regulator in a clean, dry location
Plug the remaining openings in the hose and valve
Empty and clean the refrigerator and freezer
Place an open box of baking soda or other absorbent inside the refrigerator and freezer but leave the doors slightly ajar
Cover the opening at the back of the refrigerator and the water heater door with cardboard
Cover the fresh air inlet and furnace exhaust port with duct tape or aluminum foil
Clean oven and stove burners
Close any separate pilot valves
Turn off the thermostat
Batteries
Fully charge the batteries
Remove house batteries and store in a clean, dry place if possible; or, disconnect and clean all battery terminals and spray each with a protectant or coat with petroleum jelly
Make sure batteries are clean, dry, and free of dirt and acid buildup
Remove all dry-cell batteries from clocks, radios, flashlights, and detectors
120-Volt AC System
Unplug all 120-volt AC appliances
Turn off the main breakers
Clean and brighten the contacts on the shoreline cord and cover the plug end
Make sure all electrical connections are clean, dry, and tight
Miscellaneous Machinations
Thoroughly clean the coach interior
Remove all food items, including canned goods and pet food
Vacuum under cabinets and drawers
Remove all personal items that contain liquids that may freeze
Cover windows with cardboard or aluminum foil, or protect the entire coach with an RV cover
Elevate the coach onto jack stands placed under the axles to take weight off the tires
Remove heavy snow accumulation from the roof and from around the bottom of the coach