VIKING SERIES | Air and Water Heater

950 – 2500 W
3,200 – 8,500 BTU

Wallas Viking Combi boat heater

Get More from Your Heater with a Clever Combination

Viking Combi diesel heater is a two-in-one unit that allows you the enjoy the comfort of warm air and water while away from electric charging stations. In addition to forced air heating, Viking Combi has a coolant system that warms up water simultaneously. It is designed specifically for outboard motorboats and sailboats, that don’t have the capability of using engine coolant heat for water heating.

If you start your day with a water boiler full of hot water, but need to warm up more water while journeying, Viking Combi is an excellent solution. While the heater is warming up the cabin with warm air, it also warms up the water tank.

For added convenience, Viking Combi is equipped with the Wallas Advanced Control Panel providing more accurate temperature control. When you download the free Wallas mobile app, you have the option to turn the heater on remotely and enjoy a warm boat without the wait. 

Two-in-One Heater Warms Up Air and Water Simultaneously

Viking Combi’s double function heat exchanger warms up the cabin and removes fog from the windshield with hot air while providing warm water for the boiler/hot water tank through coolant circulation. 

As the power consumption in Combi is very low, a small solar panel would be sufficient to turn it to a self-sufficient unit for longer boating trips. 

Advanced Control Panel Gives You All the Info You Need With One Glance

Use heater in PI Thermo Control Mode to set a target room temperature.

Double the air volume with Air Boost for quick defrosting or drying.

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

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

Turn your heater on remotely 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.

Have hot water for basic chores or quick showers. Warm up a 25-liter (6.6 gal.) water tank in approx. 2-3 hours.
Wireless sensor sends more accurate temperature data to the control panel to maintain a smooth ambient temperature. There is also an option to have several wireless sensors.


Clean 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 CO2 and NOx emissions

Extensively tested with Neste

Improved burner efficiency for more power

The Greenboost burner burns renewable fossil-free diesel cleanly and energy-efficiently, as well as fossil-based diesel.

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 ensures a quiet sound level and dries the indoor air.

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.

Drawing 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.

Warm water is a convenient by-product of air heating; water temperature cannot be controlled separately.

Viking Combi is primarily an air heater – water is heated simultaneously.

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 Remote 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.


Wallas Viking Combi power




Fuel: Diesel, HVO renewable diesel
Power: 950-2500 W (3,200-8,500 BTU)
Operating Voltage: 12 V
Fuel Consumption: 0,10-0,25 l/h (3.3-8.5 oz/h)
Electricity Consumption: 0,4-2,6 A
Air Volume at min Heat: 33 m3/h (19 cfm)
Air Volume at max Heat: 73 m3/h (43 cfm)
Power distribution: Air 50-90 % / Water 10-40 %
Recommended Boiler Size: 25 l  (6.6 Gal.)
Length: 424 mm (16 11/16″)
Width: 140 mm (5 1/2″)
Height: 277 mm (10 7/8″)
Weight: 12 kg (26 lbs.)
Mounting: Floor or wall


Boats: 5-9 m (16-29 ft)
Camper Vans (retrofitted): MB Sprinter, Fiat Ducato 
Trailers: 4 m (13 ft)


Advanced Control Panel, wire 5 m (16 ft)
Wireless thermo sensor
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. 




Warm air


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

Do you currently have a Wallas Dt heater?

Viking Combi’s outside dimensions are similar to the older Dt models, which makes it easy to swap units.

Reach out to your distributor to learn how to upgrade to a newer model and find the best solutions for your needs.