Camco 11673 RV Mini-Tank Water Heater 4-Gallon

The Camco 11673 is a 4-gallon RV mini-tank water heater, designed to supplement (not replace) the primary RV water heater. The unit mounts under a sink or in a small compartment and uses a 120V AC connection (not 240V or propane). 750W heating element, recovery rate about 4 gallons per hour. Right at the boundary between a true storage tank and a point-of-use unit.

The use case is specific. Most RVs have a main 6-gallon storage tank serving the primary bath. The Camco 4-gallon adds capacity at a galley sink or secondary fixture where running hot water from the main tank wastes 1–2 gallons of cold water in the line before usable hot arrives. Adding the mini-tank under the galley sink eliminates that wait.

Limitations: not sized for shower use (4 gallons depletes in 2 minutes at typical RV shower flow). Not a primary water heater — supplements the existing one. The 120V power requirement is convenient (any shore-power outlet works) but means the unit is dead when running on propane and inverter-only setups.

About $200 unit. Installation is straightforward — mount under sink, connect 1/2" cold supply, 1/2" hot output to the galley sink, plug into 120V outlet. Camco's RV-specialty distribution means parts are widely available at Camping World and similar retailers. 1-year warranty.