ARTICLE: Water Heaters for Mercedes Sprinter Vans

Last updated: October 12, 2026

Choosing a Water Heater for Your Sprinter Build

Hot water is one of those things you don't think about until you plan around it wrong. Pick the heater, mounting spot, and power setup before you run plumbing, and you won't be tearing out cabinetry halfway through the build.

The Pundmann lineup

Pundmann heaters come in four configurations: 3L, 6L, 9L, and a 6L Tower. The Tower is the same capacity as the 6L in a vertical footprint, which helps when floor space is tight but you have height to spare.

Every model runs on both AC and DC. No choosing between "off-grid" and "campground" versions. The 12V element draws about 200W, and the AC element heats faster when you're on shore power or running an inverter. Plug in when you can, run off the battery when you can't.

Picking a size

  • 3L: Dishes, hand washing, quick rinses. Good for minimal builds or a galley-only setup.

  • 6L / 6L Tower: Fine for a solo traveler or a couple showering every other day with a low-flow head.

  • 9L: For daily showers, two people, or the galley and shower in use at the same time.

Bigger tanks hold more hot water but take longer to come back up to temp once you've used them.

Where to mount it

Under the galley cabinet or in a floor-level cabinet keeps it protected and out of the way. Near the galley means short sink runs; near the shower means short shower runs. In a split layout, splitting the difference keeps both runs reasonable.

Plumbing it in

Run the heater outlet through a thermostatic mixing valve before it reaches any fixture. It blends hot and cold to a set temperature, so nobody gets scalded and your hot water lasts longer.

Cold weather

In an insulated van, a heater that was hot at bedtime still gives you warm water in the morning, and the element only has to top it up instead of starting from cold. Before winter storage or any stretch below freezing, drain the tank via the PRV. Frozen water expands and will damage the tank or fittings. It takes about 30 minutes and saves a lot of money.