Heat your water simply by driving your van or using electric power at camp. The Webasto Isotemp is a marine-grade water heater built to run on your van's coolant lines while driving, or on its 750-watt (120V) electric element off your inverter and battery bank when parked. Extra-thick insulation keeps water hot for over 24 hours, and a built-in thermostat mixing valve delivers safe, consistent temperatures at the faucet.
Features:
- Dual power source — heats via engine coolant while driving or via 750W electric element off-grid
- Marine-grade construction — AISI 316 stainless steel inner tank with corrosion-resistant fittings and tubing
- Consistent, scald-safe heat — thermostat mixing valve prevents overheating while extra-thick insulation locks in warmth from the bottom up
Specifications:
- Available sizes: 4 US Gal (18 L) / 5.3 US Gal (20.06 L) / 6.5 US Gal (29.5 L)
- AISI 316 stainless-steel inner tank, high-quality polypropylene outer casing
- 1/2" NPT water connections
- 750W immersion heating element (won't overload generators or dock breakers)
- 6 bar safety valve
- 5-year limited manufacturer warranty
Installation: Save hours of research and extra trips to the plumbing store by pairing this heater with our dedicated Install Kit, sold separately.

















