Storing a Coach in Southern California

Inland Southern California storage is a sun and thermal problem more than a freeze problem. A coach parked in the San Gabriel Valley sees a large majority of days in direct sun, and a dark sidewall or a roof membrane can run fifty degrees above ambient at midday. That load degrades EPDM and TPO membrane, chalks gel coat, hardens every rubber seal and cooks sealant beads until they craze. Nothing in a storage routine pays back better than reducing the hours of direct sun on the roof and the south wall.

Covered storage is the best answer, and a fitted breathable cover is the second best. Avoid a tarp, because it traps moisture and it abrades the finish every time the wind moves it. Before the coach goes into storage, inspect and refresh the roof sealant, since a marginal Dicor bead will not survive six months of heat cycling and the first rain will find it. Wash and wax the exterior. Wax is a sacrificial layer against sun, and on a stored coach it is doing more work than on a driven one.

Close the LP tank valve at the tank, then run the appliances briefly to bleed line pressure down, then shut everything off. Storing a system under pressure for months is how a hardened regulator diaphragm or an aged flare fitting becomes a leak you discover on the first trip out. Do not store the coach with a leaking or suspect LP system on the theory that you will deal with it later. A timed pressure drop test before storage is cheaper than the same test after a season of sitting.

Batteries want either full disconnect or an active maintainer, not a compromise between the two. Lead acid batteries sulfate at partial charge and self discharge faster in heat, so a battery disconnect switch plus a monthly top up, or a shore connection with a converter that has a proper float stage, both work. Lithium iron phosphate prefers to sit at roughly 50 to 60 percent state of charge with the battery management system awake but idle, and it should not be left on a lead acid float profile for months.

Dump and rinse both waste tanks, then leave the valves closed with a small amount of water and treatment in the black tank so the seals do not dry out. Drain the fresh tank and the water heater, and either blow the lines down or pull them down with RV antifreeze. Inland freezing is occasional rather than routine, but a stagnant fresh system in heat grows biofilm, and that becomes a sanitizing job in spring. Leave the water heater bypassed and the low point drains open.

Inside, defend against heat and stillness. Pull all food including canned goods and anything sealed in plastic, because heat and time defeat both. Prop the refrigerator doors open with the appliance off, leave cabinet doors ajar, and put a moisture absorber in the galley and the bath. Close the blinds and shades to protect upholstery and dash surfaces. Remove electronics that do not tolerate a 130 degree cabin, which includes most laptops, printers and anything with a lithium pouch cell inside it.

Tires flat spot when a coach sits on them in heat, and the sidewall damage is not always visible. Inflate to the sidewall maximum for storage, park on boards rather than directly on asphalt, which leaches oils, and cover the tires against sun. Move the coach a few feet every month or two if the facility allows it. Also note the date code on each tire, because RV tires age out on time rather than on tread depth, and seven years is the common replacement threshold regardless of appearance.

Rodents are the most expensive storage failure we see. They enter through the underbelly, around plumbing penetrations, at the propane compartment and through the chassis bay on a motorhome, and once inside they nest in the furnace duct and chew wiring harnesses. Seal penetrations with copper mesh and expanding foam rather than steel wool, which rusts away. Do not use poison inside a stored coach, because a rodent that dies inside a wall becomes a separate problem. On the return, inspect wiring and duct before running anything.