How much hot water does the Aqueous 12v water heater 6l unit hold?

The Aqueous 12v water heater 6l features a compact 6 liter (1.5 gallon) tank specifically designed for van builds. This point-of-use system provides hot water on demand, eliminating the long wait times associated with larger storage cylinders.

How fast does it heat up?

A 160-watt heating element gives rapid heat-up for its size, and placing the unit right at the point of use cuts the water and time wasted waiting for hot water to arrive.

What temperature can I set it to?

A variable thermostat lets you select any temperature between 30°C and 75°C (about 86°F–167°F).

What power does it require?

It runs on 12V DC (12V/160W, ~13.3 amp-hours), making it a good match for van and off-grid electrical systems.

Is it safe and durable?

Yes — it includes over-temperature, over-pressure, and run-dry protection, plus a combination pressure-relief and non-return valve. The patented glass-lined tank, high-impact ABS body, and polyurethane insulation are built for long life and heat retention. It's also IPX4 water-resistant.

It comes with a 12-month warranty.

Aqueous 6L 12V water heater, front with thermostat dial and power leads

Back of the Aqueous 6L 12V water heater showing the mounting cleat slot and fittings

Typical van water heater plumbing layout with tank, pump, heater and mixer

Sandy Vans overview and review of the Aqueous 12V water heater

Aqueous

12V Water Heater (6L)

Name: 12V Water Heater (6L)
Brand: Aqueous
Price: 499.0 USD
Rating: 4.00 (1 reviews)

~~$595.00~~ $499.00 Save 16%

Shop 5.0 Shop rating (174) on Google

Product variants

Pickup available at Sandy Vans HQ

Usually ready in 2-4 days

Hot water from your 12V system, no propane and no generator.

The Aqueous 6L is a compact 12V tank water heater. Plumb cold in and hot out, wire it to your house batteries, set the dial, and it keeps 1.5 gallons hot for showers and dishes.

Fits: Any van with a 12V house system and pressurized water. Not compatible: 24V or 120V-only systems (this is the 12V model).

6 L (1.5 gal) glass-lined tank with polyurethane insulation
Thermostat dial from 30 to 75 C (86 to 167 F)
About 12 A draw while heating, roughly 15 to 20 minutes to full temperature in our testing
1/2 in BSP cold in and hot out
Built-in protection: over-temperature, over-pressure and run-dry, plus a pressure relief and non-return valve
Slides onto an included wall cleat with foam inserts, so it's quiet and easy to remove

Ships free. Pair it with: SEAFLO 33 Series pump · Shower port. Want 120V too? See the Duoetto Gen 3.

See it on your van. Add the 12V Water Heater (6L) to your build in our 3D Van Builder and preview it on a real Sprinter before you buy.

Product Details

Why we use the Aqueous in our builds

A 12V water heater is the simplest way to get hot water in a van. There's no propane and nothing to light, and it runs off the same batteries as everything else. On many of our builds we just leave it on for the whole trip. The insulated tank holds temperature and the element only kicks on when it needs to.

How we plumb it

On simple builds we run straight from the water tank, through the heater, and out to the shower, with no mixing valve. Set the temperature on the dial and you're done. For a full galley and shower setup, a mixing valve lets you blend hot and cold.

What to expect

A 12V heater takes longer to warm up than a 120V one. We find it reaches full temperature in about 15 to 20 minutes. Flip it on before a surf and the water's hot when you get back.

Fitment & Compatibility

Fits: Any van with a 12V house system, incl. Mercedes Sprinter

Not compatible with: 24V or 120V-only systems

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

Specifications

Brand	Aqueous
Model	AQU-6-12
Capacity	6 L (1.5 gal)
Voltage	12V DC
Power rating (Aqueous)	12V, 180 W, 13.3 A rated
Measured draw (our testing)	About 12 A while heating
Heat-up time (our testing)	About 15 to 20 minutes to full temperature
Thermostat	30 to 75 C (86 to 167 F)
Fittings	1/2 in BSP inlet and outlet
Safety	Over-temperature, over-pressure, run-dry protection; 0.85 MPa pressure relief and non-return valve
Construction	Glass-lined tank, ABS body, polyurethane insulation, IPX4
Dimensions	305 x 305 x 304 mm (12 x 12 x 12 in)
Mounting	Slide-on wall cleat with foam inserts
Warranty	12 months

What's in the Box

Aqueous 6L 12V water heater
Combination pressure relief and non-return valve
Wall mounting cleat with foam inserts

Install Time1 to 2 hours

DIY FriendlyYes, basic plumbing and 12V wiring

Drilling RequiredYes, screws for the wall cleat

The Aqueous mounts on the included wall cleat. Slide it down onto the cleat and the foam inserts keep it from rattling. Plumb cold water in and hot water out with 1/2 in BSP fittings, then wire it to your 12V system. The Aqueous manual shows the plumbing layout.

Lights

Green: powered on
Red: heating

Mistakes to avoid

Swapping inlet and outlet. Cold goes in, hot comes out.
Running it dry. Fill the tank with water before you power it on.
Undersized wiring. It draws about 12 A while heating; wire and fuse it for that load. Reach out if you're unsure.

If the heater stops working, the thermal cutout may have tripped. The manual shows how to reset it.

Questions? Reach out to our team at products@sandyvans.com or (619) 812-1903.

Tools You'll Need

Drill and driver for the cleat
Plumbing fittings and thread seal
Wire, crimps and an inline fuse

Download the install instructions (PDF)

See all Sandy Vans install videos & manuals →

How to choose a van water heater

1. What power do you have?

How to choose: A 12V heater runs off your house batteries anywhere. If you also have shore power or a big inverter, a dual 12V and 120V unit heats faster.

2. How much hot water do you use?

How to choose: 6 L covers quick showers and dishes in a small van. Larger tanks hold more but take longer to heat on 12V.

3. How simple do you want the plumbing?

How to choose: A tank heater with a temperature dial can feed a shower directly, without a mixing valve.

Before you order

12V house system with room for about 12 A while heating
Pressurized water pump, like the SEAFLO pump
Mounting spot on a wall for the cleat

How the Aqueous stacks up

Power: 12V, about 12 A while heating.
Capacity: 6 L insulated tank.
Control: thermostat dial, 30 to 75 C.
Mounting: slide-on wall cleat with foam inserts.
Need 120V too? See the Duoetto Gen 3.

How long does it take to heat up?

In our testing, about 15 to 20 minutes to reach full temperature. A 12V heater is slower than a 120V one, so many of our customers just leave it on for the trip.

How much power does it use?

About 12 A on 12V while the element is heating. Once the tank reaches temperature, the element turns off until it's needed again.

Do I need a mixing valve?

Not necessarily. On simple builds we run straight from the tank through the heater to the shower and set the temperature on the dial.

How does it mount?

It slides onto the included wall cleat. Foam inserts keep it quiet, and it lifts off easily for service.

It stopped heating. What do I do?

The thermal cutout may have tripped. The manual shows how to reset it. Reach out to our team at products@sandyvans.com or (619) 812-1903 if that doesn't fix it.

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.