Cabin systems
A luxury Sprinter can be stored for winter without much mileage on the odometer and still need substantial preparation. Water can remain in a seldom-used shower. A house battery can feed equipment after the main cabin lights go out. A heated garage can lose power.
Build a storage plan around the installed equipment and the lowest temperature the van might experience. There is no single valve sequence or battery setting that applies to every conversion.
Make an equipment list before you book winterization
List every water-using component: fresh tank, pump, faucets, toilet, shower, outside sprayer, refrigerator water connection if present, and water heater. Photograph the labels and locate their manuals. Ask the builder which lines, valves or tanks sit outside the heated space.
If a shop performs the work, request a written list of the systems covered. “Winterized RV” on an invoice is less useful than a record naming the heater, tank drains, filters and fixtures. Take photos of the final labeled valve positions so spring recommissioning starts from known information.
Follow the water heater’s own instructions
Different heaters require different treatment. As one example, Truma’s AquaGo winterization guidance describes cooling and depressurizing the unit, using the specified bypass arrangement and draining it through its Easy Drain mechanism. It warns against high-pressure air or antifreeze through the unit and gives conditions for using antifreeze with a bypass kit.
That procedure is specific to AquaGo. It is not a recipe for a different Truma product or another brand. If you cannot positively identify the equipment and required bypass arrangement, have a qualified service provider winterize it. Draining the fresh tank alone does not establish that the entire system is empty.
Give the starter and house batteries separate plans
Ask the chassis service advisor about the Mercedes starter battery, and use the house battery manufacturer’s guidance for the conversion bank. Record the specified storage charge, temperature limits and inspection interval. Include how charging is prevented or controlled when the battery is too cold.
Some lithium systems have low-temperature protection or heating; others do not. Do not assume a battery is protected because the control panel calls it lithium. The Victron Lithium Smart manual, for example, contains product-specific operating limits that should not be transferred to another battery.
Have the installer explain what remains powered after the coach disconnect is switched off. Trackers, alarms or other devices may be on separate circuits. If you leave a charger connected, confirm that the equipment, supply and storage facility permit that arrangement, and arrange checks for a tripped supply.
Put the cabin away clean and dry
Remove food, empty and clean the refrigerator according to its manual, and dry wet bathroom and floor areas. Take home damp towels and bedding. Clean spills under seat bases and in cabinet corners before they spend months in storage.
Use the storage or ventilation positions specified for appliances. Do not block required vents or pack equipment compartments with linens. Check the van periodically for moisture, pest activity and water entry, especially after storms. Photograph anything new before arranging a repair.
Record the return-to-service work now
Put a spring checklist in the driver’s folder: chassis checks, tire inspection, battery reconnection or charging procedures, plumbing recommissioning and any required water-system sanitation. Use the relevant manuals rather than reversing the winter steps from memory.
Book the first outing near home after those checks are complete. Fill and test the water system where a leak can be dealt with, verify charging and run the equipment before loading luggage. Our service-shop guide helps divide chassis work from coach work when you need assistance.
Source links appear beside the details they support. Equipment instructions apply to the named product; use your own van’s manuals. Destination conditions checked September 8, 2026.
