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Isotemp Slim Square (4.2 gallon)


4.2 gallon marine-grade water heater.

This is the only square profile Slim model which can make it easier to install into tight spaces in your van build.

This water heater is a fantastic way to get hot water by simply running or driving your van. It can heat the water through the van’s coolant lines or using the 750 watt (120 VAC) electric element off your inverter when you’re not driving. Check out our blog post about Isotemp water heaters.

Save time, headaches and general misery tracking down all the parts you'll need with our Isotemp Installation Kits that include everything you need to connect the water heater to your van's coolant system and a very helpful, step-by-step installation guide!

FREE ground shipping to the lower 48 states.

14 in stock (can be backordered)

SKU: 601623QX00003 Category: Tags: , ,
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  • Inner tank made of AISI 316 stainless steel
  • All Isotemp water heaters use two thermostats: a temperature thermostat and a safety thermostat designed to trip in the event the tank is run dry
  • All Isotemp water heaters come standard with a mixing valve that regulates the temperature of the water coming out of the tank so that water heated to 160+ degrees can be thermostatically adjusted to your prefered temperature and extends the capacity of onboard hot water by using only a fraction of the water in the tank to produce the desired water temperature.
  • 750 Watt immersion heating element specially designed to heat water at bottom of tank
  • Robust design and manufactured to highest-quality marine standards for long service life
  • All Isotemp products are CE certified and manufactured in ISO certified facilities
  • All Isotemp tanks are covered by a 5-year limited warranty against leakage due to manufacturing defect or corrosion and a 2-year warranty on all other parts
  • Extra-thick insulation for low temperature loss, high performance
  • Extra-long corrugated coils for high heat exchange efficiency
  • The Isotemp water heaters can be connected to the coolant lines even if the water tank is empty (before you've connected the water lines), however the electrical element should not be turned on until water lines have been connected and the tank has water inside.

Check out our blog post about Isotemp water heaters here.

Dimensions (PDF)
Manual (PDF)

Additional information

Weight 560 oz
Dimensions 24 × 22 × 11 in

Water Heater Only, Water Heater – With Promaster Installation Kit