Outside:
Wash the outside of the RV with soap, water and a long-handled scrub brush. Scrub the top of the RV & tires as well.
Inspect roof caulking, moulding and seams. Check for exposed fasteners, cracked seams, UV deterioration, mold and mildew, water spots on the ceiling.
Spray roof seams and window seals with a garden hose to check for leaks. Search the interior for moisture. Seal any leaks with a silicone sealant (Di-Cor) or replace the rubber gaskets.
Remove the awning, if applicable, and wash with soap and water to remove stains. Allow the awning to dry thoroughly before placing it back on the RV.
Engine:
Oil & Lube job.
Change the generator(s) oil.
Fill fuel tank up to prevent moisture from building up. Add a fuel stablilizer such as Sta-Bil Fuel Stablizer to prevent fuel from deteriorating & gumming up the engine.
Make sure all fluid levels under the hood are full.
Over inflate all tires (including the spare) by 5psi. Tires can lose up to 1psi a month while sitting due to air slowly seepiing through the pores in the tire.
Tires on wood (no ground contact).
Tire covers on all tires (including the spare) to protect them from the UVs. The sun accelerates tire deterioration.
Make sure the startup & house batteries are charged completely. Check the water level & fill with distilled water. A solution such as BatteryMinder can help desulfinate the plates and help maintain the battery.
Disconnect the negative battery terminal(s) if leaving in RV.
Do not store the batteries on a floor, especially not a cement floor. Cement floors have been known to drain batteries.
Replace the air conditioning filter with a clean filter.
Cover exterior portion of the air conditioner.Lower & secure solar panels.
A good tarp that can breathe to cover your RV.
Inside:
dehumidifiers
chemical water absorbent
http://www.domyownpestcontrol.com/aabsorb-waterbased-chemical-absorbent-p-1305.html
Follow instructions in owner's manual for winterizing the unit.
Fill propane tank(s) up to prevent moisture from building up.
Make sure that propane system is shut off at the tank and that all valves & gas appliances are shut off. (Turn on to burn off excess gas in line 1st?)
Cover regulator on propane cylinder.
Turn off gas valves for refrigerator/freezer, stove/oven, furnace, hot water heater, gas heater, etc.
Lubricate all rubber seals.
Disconnect shore electric power to the RV.
Disconnect all electrical cords from outlets.
Drain black & grey water tanks, add 1/4 cup of chlorine bleach per 15 gallons of tank capacity. Put peanut oil (valve lube) in toilet, and 1 cup in each waste tank.
Empty the fresh water tank into black & grey tanks & add 1/4 cup of chlorine bleach per 15 gallons to fresh water tank & fill it back up again.
Drain black & grey water tanks after driving around sloshing water around to loosen debris. Use Flush King to clean the black and gray tanks. Lubricate the termination valves with WD 40.
Turn off hot water heater & open the low point hot & cold drain lines to empty tank. Using the water pump will help force water out, but turn it off as soon as the system is drained. Add 1/4 cup of chlorine bleach per 15 gallons of tank capacity & fill it back up & drain again.
Recap all drains & turn off water pump.
Drain & flush all water lines, using compressed air or at least the low-point drain lines.
Leave fresh water tank full if storing in desert (possibly more termperate & moist areas). Water should help prevent the lines, pump and tank from completely drying up. In cold areas probably drain all tanks & lines & use antifreeze in toilet & lines.
Put non-toxic antifreeze in the water lines (in the toilet & down sink & shower drains. 1-2 gallons should be plenty. Switch on the water pump to suck up the antifreeze into the lines. Open each faucet slowly, one at a time, until the red antifreeze starts coming out then shut off the faucet & water pump.
Close the water bypass valves to hot water tank.
Buy a couple of gallons of distilled water at the local Wal-Mart and leave in toilet & drain traps to prevent any scale problems in case the water evaporates.
Defrost the freezer & clean refrigerator/freezer with a damp cloth. Leave doors open & place Arm & Hammer (baking soda) or crumpled newspapers inside to absorb ordors.
Clean cooking grease behind stove & down walls.
Clean & vacum interior well to remove unseen food particles.
Open all draws, cabinets and doors to prevent moisture buildup and to help regulate the temperature.
Leave roof vent(s) & windows cracked for air circulation.
Cover windows, close curtains & blinds to prevent the interior from the sun and fading. Place a sun shield in the front windshield.
Storage:
Park exactly east/west with the RV side with most windows due north.
Park in the shade, park away from trees or bushes that can be reached by spiders or windblown insects. Keep windows or vents cracked and air circulating with fans to prevent heat buildup.
Leveling jacks with pads should be down.
Pest Control:
Cover all external outlets, such as furnace outlet, to prevent critters from entering. Can of expanding foam sealer to seal openings.
Put plugs in sink, shower & bathtub drains; make sure the toilet seats are down (critter prevention?)
Mix equal parts of sugar and borax. Place the sugar/borax mixture strategically around the trailer in small containers (jar lids work just fine). Ants are attracted to the sugar and carry it back to the mound and within a week or two the borax will kill the ants.
Spread roach and ant powder around the tires, leveler jacks etc. Remember if it rains the powder will have to be re-applied. Ant traps, moth balls.
For preventing a roach or ant infestation sprinkle diatomaceous earth and/or 20 Mule Team Borax around and between cabinets, on floors and into any crevices. Do this with caution, as you are going to be the one that has to clean this up when you are ready to use the RV again.
Bounce sheets tucked into cabinets, basement storage area & wherever a rodent might nest. May last up to 4 months.
Use distilled white vinegar or sudsy ammonia and wipe down EVERYWHERE to eliminate the pheromone (scent) trail that scout ants leave for other ants.
Electromagnetic pest control: this device operates based on wavelengths and frequencies that are in the wiring of your house/recreational vehicle.Ultrasonic pest control: this device is very similar to the electromagnetic device but deals with ultrasonic waves and is especially effective against the larger pests such as rats and mice.
Ionic pest control: this device works by using negative ions to clean the air, an added benefit of this device is that the negative ions also ward off insects.