1400 – 4500 W
4,700 – 15,300 BTU

Wallas Spartan Twin boat heater

Introducing the Most Powerful Wallas Diesel Heaters

As one of our most powerful models, the Wallas Spartan Twin offers the most advanced control features in the marine heater market, maximizing convenience and versatility. The Advanced Control Panel can be accessed remotely by Wallas mobile app, which enables you to turn the heater on from anywhere. The wireless sensor monitors the indoor temperature with high accuracy, maintaining smooth temperature stability for maximum comfort.

In determining how to maximize your application, an important feature of the Spartan Twin is it’s two makeup air inlets and two warm air outlets. In comparison, the Spartan Air has three inlets and three outlets. Multiple inlet air sources result in better efficiency and fresher air indoors. Both the Spartan Twin and Spartan Air model heaters are rated 4.5Kw, excellent choices for boats from 9 to 12 meters (29-40 ft). 

Two Inlets and Outlets Improve Airflow and Efficiency

Two inlets take fresh air from outside and recirculate heated air in the cabin. This improves efficiency and ensures oxygen rich air in the cabin. 

Two outlets reduce power consumption and facilitate smooth distribution of heated air throughout the cabin. The bigger the cross-sectional area of the ducts are, the less it reduces airflow and makes the best use of the ventilation fan.

The Advanced Control Panel Gives You All the Info You Need with One Glance

Use heater in PI Thermo Control Mode to set a target temperature or switch to Manual Mode and control heat with six power levels (1-6).

Blow fresh air with Ventilation Mode when heating is not needed.

Superior ventilation volume in Air Boost Mode provides extremely fast defrosting and drying – The highest in its class!

Switch to High Altitude Mode  when traveling in high altitudes to adjust the combustion.

Wallas Mobile App for Remote Access

Turn your heater on remotely with the Wallas Remote App and enjoy a warm boat upon arrival.

Monitor cabin temperature and battery voltage remotely from home to be better prepared for the day.

Adjust temperature locally on boat with your phone without having to reach to the control panel.

Keep your heater always updated with the latest features.


Open and closable air vents can be installed in the indoor space or on the deck for maximum comfort.


Wireless sensor sends more accurate temperature data to the control panel to maintain a smooth ambient temperature.


Fully enclosed laminar burning process does not leak odors into the cabin and dries the indoor air.


Brushless blower motors have a very long life-cycle, supporting reliably long service intervals.



Cleaner Burning

Updated software optimizes fuel and electricity consumption

Calibrated to burn renewable fossil free diesel (e.g. HVO)

Larger burner burns fuel slower resulting in ultra low NOX emissions

Extensively tested with Neste

Improved burner efficiency for more power

The Greenboost burner burns renewable fossil-free diesel cleanly and energy-efficiently in addition to fossil based diesel fuels.

Two inlets and outlets improve fresh airflow and efficiency.

Combustion air is taken from outside the boat through the outer coaxial pipe.

Exhaust gas is safely expelled outside through the inner coaxial pipe keeping the indoor air clean and odorless.

Fully enclosed laminar burning process creates heat with no exposed flame and ensures a stable, wind resistant burn.

Energy-efficient Wallas Greenboost technology saves fuel and electricity.

Variable output eliminates system cycling and reduces noise.

Brushless blower motors have a very long life-cycle and require less frequent servicing.

Feeding fuel directly from the main tank of the vessel saves space and eliminates the need for a separate tank.

Durable Finnish design and manufacturing keep your heater intact for years.

Low temperature on unit and exhaust pipe improves safety.

Advanced Control Panel enables intelligent temperature control.

Wallas Remote App heater control works locally on boat with no WiFi by using short-range wireless connection.

Heater can be accessed from any location through a boat WiFi router with the Wallas App.

Wireless sensor monitors cabin temperature with improved accuracy.

Remote accessibility enables system updates and diagnostics.

Heater can be set up to operate with Yamarin Q-infotainment, Buster Q, and Askeladden C-command screens.


Spartan Air power


Wallas Spartan Fuel


Spartan Air electricity


Fuel: Diesel, HVO renewable diesel
Power: 1400-4500 W (4,700-15,300 BTU)
Operating Voltage: 12 V
Fuel Consumption: 0,16-0,46 l/h (5.4-15.5 oz/h)
Electricity Consumption: 0,7-4,5 A
Air Volume at min Heat: 102 m3/h (60 cfm)
Air Volume at max Heat: 226 m3/h (133 cfm)
Length: 424 mm (16 11/16″)
Width: 165 mm (6 1/2″)
Height: 278 mm (10 15/16″)
Weight: 15 kg (33 lbs)
Mounting: Floor or wall
E-mark Approved for Vehicles: Yes


Boats: 9-12 m (29-40 ft)
Camper Vans: MB Sprinter
Trailers: up to 6 m (20 ft)


Advanced Control Panel, wire 5 m (16.4 ft)
Wired and wireless thermo sensors
Fuel line 4 m (13 ft)
Power cable 4 m (13 ft) with connector and integrated fuse 15 A
Mounting plate, feet brackets
Accessory bag including essential clamps and screws


Stainless Steel, High-Grade Aluminum, Other Corrosion-Resistant Materials

Recommended builds should be used as general guidelines. The needed heat output is based largely on the material (wood, fiberglass, aluminum etc.) and structure of the boat. Always discuss this with a Wallas distributor, before making your purchase. 

Technical values are measured in a reference measurement wall, which is constructed to represent a typical boat installation. Values have been measured with maximum length of ducting, exhaust pipe, fuel line, and power cord. The figures allow for 10 % reserve – yours may vary.

Wallas diesel heaters and stoves are designed to run with standard road and boat diesel, as well as renewable fossil free diesel. Check with your distributor for further details on best options for your needs.

Accessories in black are included in the standard package. Accessories in blue are additional. 

Browse product manuals, spec sheets and more in the Documents Center

Do You Currently Have a Wallas Dt/D Heater?

Spartan Twin is a 4,5kw heater, which replaces the older Wallas 40 D/40 Dt models. With two 75 mm air hosing and similar outside dimensions, upgrading to the Spartan Twin is generally quick and easy.

Reach out to your nearest distributor to learn how to upgrade to a newer more energy efficient model and save money.