Can the Duoetto Gen 3 Water Heater provide hot water when off-grid?

Yes! The Duoetto Gen 3 is designed to operate on both 12V DC power, drawing from your RV battery, and 120V AC power, suitable for shore power or generator use. It intelligently switches between these sources to ensure you have hot water available regardless of your power situation.

Is the Duoetto Gen 3 Water Heater easy to install in my van or RV?

The Duoetto Gen 3 is engineered for straightforward installation. It includes universal mounting brackets, allowing for wall or floor mounting. The unit features NPT threads for both water inlet and outlet connections. Refer to the provided manual for detailed installation instructions.

What safety features are included with the Duoetto Gen 3 Water Heater?

Safety is a priority with the Duoetto Gen 3. It is equipped with over-temperature and run-dry protection. A combination Pressure & Temperature Relief Valve (PTR) is included to prevent overpressure. In the event of an issue, an external reset button with a red indicator light allows for easy restoration of operation.

How durable and long-lasting is the Duoetto Gen 3 Water Heater?

The Duoetto Gen 3 Water Heater is built for durability and longevity. It has achieved ETL Intertek certification to UL 174 standards, meeting rigorous US safety requirements. Key construction features include a resilient outer case, an SPCC steel tank with an enamel coating, and a single weld line for enhanced tank integrity.

Duoetto Gen 3 12V/120V van water heater in black with the digital temperature display

Duoetto Gen 3 water heater showing the inlet, outlet and pressure relief fittings

Duoetto Gen 3 water heater with dimensions marked for planning a van install

Sandy Vans

Duoetto Gen 3 Dual 12V/120V Water Heater

Name: Duoetto Gen 3 Dual 12V/120V Water Heater
SKU: WATHEAGEN3
Price: 649.0 USD

$649.00

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Product variants

Pickup available at Sandy Vans HQ

Usually ready in 2-4 days

Hot showers off the battery, faster hot water on shore power.

The Aus J Duoetto Gen 3 is a 2.65 gallon water heater that runs on 12V DC or 120V AC. Plug in at camp and it heats on 1440W of AC power. Off grid, it switches to 12V on its own and keeps the tank hot at 300W. Set the temperature anywhere from 86 to 140°F on either power source.

Fits: universal, any van, RV or boat with room for the tank and a 12V and/or 120V supply. Built for galley and under-bench water systems. Not compatible: setups with no space for a 21.9 x 13.2 x 14.8 in tank.

Dual power: 12V DC (300W) and 120V AC (1440W), with automatic switching that defaults to AC when it's available
2.65 US gallon tank in enameled steel with polyurethane insulation to hold heat
Adjustable temperature from 86 to 140°F, from the front panel or the included remote
Safety built in: pressure and temperature relief valve, over-temperature and run-dry protection, and an external reset button
ETL listed to UL 174 for electric storage tank water heaters
Wall or floor mount brackets and NPT threaded inlet and outlet

Only need 12V? See the smaller Aqueous 12V Water Heater (6L). Pair it with a SEAFLO 33 Series water pump and a stainless shower port.

See it on your van. Add the Duoetto Gen 3 Dual 12V/120V Water Heater to your build in our 3D Van Builder and preview it on a real Sprinter before you buy.

Product Details

Why we like the Duoetto Gen 3

Most van water heaters pick a lane: 12V only, or 120V only. The Duoetto does both. On the road it keeps a small tank hot from your house batteries, and the moment you plug in at a campground it switches to shore power and stops drawing from the battery bank.

What you get

2.65 gallon tank in enameled steel, enough for quick showers and dishes
Two power sources with automatic detection and switching
Front panel and remote control to set the temperature from 86 to 140°F
Pressure and temperature relief valve plus over-temperature and run-dry protection
Wall or floor brackets with bolts, washers and screws

Where it fits in a build

Plan for a spot near the water pump with room for the tank, the plumbing loops and access to the relief valve and reset button. It's universal, so it works in any van or RV layout, not just a Sprinter.

Fitment & Compatibility

Fits: Universal, any van, RV or boat

Not compatible with: No room for a 21.9 x 13.2 x 14.8 in tank

Not sure your build qualifies? Reach out to our team.

Specifications

Brand	Aus J Duoetto
Model	Duoetto Gen 3
Tank capacity	2.65 US gallons (10 L)
Power	12V DC at 300W; 120V AC (60 Hz) at 1440W
Power switching	Automatic; defaults to 120V AC when available
Temperature range	86 to 140°F on 12V and 120V
Reheat trigger	Element turns on when the tank drops 39°F below the set temperature
Tank	SPCC steel with porcelain enamel lining, polyurethane insulation
Heating element	Incoloy 840
Safety	Pressure and temperature relief valve, over-temperature and run-dry protection, external reset
Certification	ETL Intertek, certified to UL 174
Connections	NPT threaded inlet and outlet
Mounting	Wall or floor (base) mount, brackets included
Dimensions	21.85 x 13.19 x 14.76 in
Weight	20 lb (empty)
Remote control	Included
Fitment	Universal, any van, RV or boat

What's in the Box

Duoetto Gen 3 water heater
Remote control
Mounting brackets (2)
Bolts (4)
Washers (4)
Timber screws (8)
User manual

DIY FriendlyIntermediate; plumbing and 12V wiring required

Drilling RequiredYes, to mount the brackets

The Duoetto Gen 3 mounts to a wall or a floor with the included brackets. Plumbing should be done by a qualified person, and electrical connections should follow the manual. Install time depends on your build, so reach out to our team at products@sandyvans.com or (619) 812-1903 for an estimate or a shop install.

Mistakes to avoid

Powering the heater before the tank is full. Fill it and check for leaks first.
Mounting to a surface that can't hold it. Aus J calls for hardware and backing that can take 4 times the filled weight.
Undersized 12V wire. Use the wire chart in the manual for your run length and fuse the main circuit at 40 to 50A.
Blocking the relief valve or reset button. Leave access to both.

Manual

Duoetto Gen 3 installation and user manual

Tools You'll Need

Drill and driver
Pipe thread sealant and wrenches for NPT fittings
Wire strippers and crimper
Fuse holder with 40 to 50A fuse
Multimeter

Download the install instructions (PDF)

See all Sandy Vans install videos & manuals →

How to choose a water heater for your van

1. What power do you have?

How to choose: If you plug into shore power often, a dual 12V/120V heater saves your batteries at camp. If you're always off grid, a 12V-only heater can be enough.

2. How much hot water do you use?

How to choose: A 2.65 gallon tank covers quick showers and dishes for one or two people. Smaller tanks heat faster but run out sooner.

3. Where will it mount?

How to choose: Measure the cabinet or bench space first. The Duoetto needs 21.85 x 13.19 x 14.76 in plus room for fittings and access to the relief valve.

4. What can your batteries support?

How to choose: On 12V the Duoetto draws 300W, about 25A. Make sure your battery bank and charging can keep up with your shower routine.

5. Safety and certification

How to choose: Look for a pressure and temperature relief valve, run-dry protection and a recognized listing like UL 174.

Before you order

Measured the mounting space
Planned a 12V circuit with a 40 to 50A fuse
Shore power inlet if you want 120V heating
Water pump and shower outlet chosen

How the Duoetto Gen 3 stacks up

Power: 12V and 120V with automatic switching.
Capacity: 2.65 gallons.
Mounting: wall or floor, universal fit.
Safety: relief valve, run-dry protection, ETL listed to UL 174.
Want something smaller and 12V only? See the Aqueous 12V Water Heater (6L).

Does the Duoetto Gen 3 run off my van batteries?

Yes. It heats on 12V DC at 300W, which is about 25A at 12V. When you plug into 120V shore power it switches to AC on its own and heats faster at 1440W.

What temperature can I set it to?

Anywhere from 86 to 140°F, on both 12V and 120V. Adjust it on the front panel or with the included remote.

Is the remote included?

Yes, ours ships with the remote control. It turns the heater on and off and adjusts the temperature on both power sources.

Will it fit my van?

It's universal and fits any van, RV or boat with room for the tank: 21.85 x 13.19 x 14.76 in. It mounts to a wall or a floor, so it usually goes in a galley cabinet or under a bench near the water pump.

What size fuse and wire do I need?

Aus J recommends a 40 to 50A fuse on the main 12V circuit and a 5A fuse on the small switching wires. Size the main wire to the round-trip run length using the chart in the manual, or reach out to our team and we'll help.

How long does installation take?

It depends on the build: where the heater mounts, how the plumbing runs and how far the 12V run is. Reach out to our team at products@sandyvans.com or (619) 812-1903 and we'll give you an estimate.

Can I turn it on before the tank is full?

No. Fill the tank completely and check every connection for leaks before you power it. Running it dry damages the element; the run-dry protection is a backup, not a feature to rely on.

Do you install products for customers?

Yes. Many SV products can be professionally installed at our San Diego shop. Reach out to our team to schedule. Email products@sandyvans.com or call 619-812-1903.

What is your shipping and return policy?

Most SV products ship free. For returns, see our Returns & Refunds policy or reach out to our team at products@sandyvans.com.

Can I reach a real person with questions?

Always. We are a small team in San Diego. Email products@sandyvans.com or call 619-812-1903 and you'll get a real answer, not a chatbot.

Where are you located?

9393 Trade Pl, San Diego, CA. Come visit the shop, we'd love to show you around.

Does Sandy Vans offer financing?

Yes. Many financing options are available. Set up a call with a sales associate to learn more.

Still have a question? Email the team and you'll get a real answer.