Heat, water and ventilation

This hub is for you if you plan to use your van when nights drop toward freezing, or need to store it through a winter. Heat, moisture and water are linked: the heater you choose affects how wet the van gets, and how warm you keep the cabin decides whether your plumbing survives. The three guides here work best read together.

The key decisions

How you'll heat the van

A sealed diesel heater is the common choice because it draws combustion air from outside and sends exhaust outside, so it adds heat without adding combustion moisture. The diesel heater install guide compares the three mounting positions (inside on the floor, in the front seat base, or under the van) and walks through the install to Webasto's Air Top 2000 STC manual. The rules don't change with location: combustion air must not come from the cabin, and the exhaust must exit through sealed holes and point away from doors, windows and vents.

How you'll manage moisture

Breathing, cooking and wet gear fill a small van with water vapor, which condenses on glass and bare steel. The condensation guide ranks the fixes: vented heat instead of an unvented propane heater, a roof fan on low exhaust with a cracked window for fresh air, insulated window covers, and a cheap hygrometer. The EPA advises keeping indoor relative humidity below 60 percent, ideally between 30 and 50 percent.

What happens to your water in a freeze

If you're storing the van, you need to get water out of the tank, pump, lines, water heater and fixtures. If you're living in it, the goal changes: keep plumbing inside the heated space or carry water in jugs. The winterizing guide compares draining, a low-pressure blow-out (Camco says never above 50 PSI) and RV antifreeze, and explains why most owners do a blow-out followed by a little antifreeze in the pump and drain traps.

A sensible order

Step	What to do	Guide
1	Choose and install vented heat, and fit a CO alarm	Diesel heater install
2	Set up ventilation, window covers and a hygrometer	Condensation
3	Decide how your water system handles a freeze, and winterize before storage	Winterizing

If you camp in the cold, also read charging a lithium battery below freezing: a heated cabin is often what keeps the battery warm enough to charge.

Carbon monoxide and when to use a professional

A sealed heater keeps combustion gases out of the cabin only while its gasket, heat exchanger and exhaust stay intact. Fit a CO alarm listed for recreational vehicle use near where you sleep, not right beside the heater outlet, test it regularly, and never run a portable gas stove or unvented heater inside the van. CDC notes that early CO symptoms such as headache, dizziness and nausea are often mistaken for flu.

Consider a qualified heater installer or RV technician if:

• You aren't confident cutting and sealing holes in the floor, or routing exhaust clear of fuel lines, brake lines and wiring.
• You want to draw fuel through your van's auxiliary fuel port rather than from a separate tank.
• The heater smokes, smells of exhaust inside or sets off the CO alarm. Stop using it until it has been checked.

Always follow your own heater's installation manual; budget heaters follow the same principles, but their limits differ.