More and more people are discovering the advantages of wood firing. Above all, this is because cast iron wood boilers usually have a service life of 50 years or more. Our wood boilers, which have the name VIADRUS, have been warmly welcomed by owners all over Sweden. Our low prices and the high quality of the products mean that we are now the market-leading retailer of cast iron wood boilers.

Viadrus Hercules U22

Wood 30-50 kW

Wood, coal, briquettes, pallets (with screws & nails)

Pellets, all oil, wood chips & gas

VIADRUS U22 heating boilers are made of cast iron sections that are pressed together and anchored with through-bolts.
This is a tried and tested technique that ensures a very long service life for your heating boiler.
Chimney-sweeps, plumbers and the entire HVAC sector are in agreement about the superior properties of cast iron heating boilers. This is because of cast iron’s high torsional rigidity and resistance to corrosion (rust).
By way of comparison, nobody would come up with the idea of manufacturing a car engine out of normal welded sheet metal.

The Viadrus Hercules U22 is a perfect heating boiler for all houses and small apartment blocks. Over the years, more than 200,000 satisfied customers across Europe have purchased this cast iron boiler. A U22 cast iron boiler places low demands on your chimney. It works both in pump-based systems with a charging unit (this is the standard solution) and in systems employing self-circulation, and is very easy to use. It is simple to load the heating boiler with large chunks of wood thanks to the large hatch, a feature that is appreciated by many of our satisfied customers. You are recommended to position a Viadrus heating boiler on a stand or base, approximately 500 mm in height. Also bear in mind that a heating boiler should be positioned a safe distance from easily flammable materials.

  • Lower demands placed on the chimney than is the case with many heating boilers
  • Potential to burn wood with a moisture level of up to 20%
  • The boilers are available in several sizes, and the number of sections controls the output
  • A service life of 50 years is common for a cast iron boiler (A normal heating boiler made of welded sheet metal can rust out in less than 8 years).
  • Can withstand approximately 100% higher pressure than heating boilers made of welded sheet metal.
  • No electronics or ceramics that can cause problems.
  • Can also easily be converted to a pellet boiler with our pellet burners
Viadrus Hefaistos P1

30-170 kW


The Hefaistos P1 is a cast iron boiler, built in sections, designed for wood. It has a wood magazine made of water-jacketed steel plate. The combustion principle comprises combustion from below with a suction fan, and this wood boiler is environmentally approved in accordance with EN 303-5, class 3. The Hefaistos P1 is available with several different outputs, ranging from 30-170 kW depending on the number of sections (3-10 sections). The wood boiler has been designed to be fired connected to an accumulator tank and can be used in both open and closed systems. The volume of the accumulator tank may not be below (25 litres of water/kW). The Hefaistos P1 wood boiler is suitable for heating everything from small houses up to large properties and mansions, as it available in several different sizes.

The Hefaistos P1 wood boiler is even more efficient than our Hercules U22, and like that model it is made by VIADRUS, which has more than 120 years of experience of cast iron and cast iron boilers. Like our U22 heating boiler, it can burn wood with a moisture level of up to 20%. The Hefaistos is one of only a few wood boilers that has a proper ecolabel, which means that you gain a long service life at the same time as saving the environment. This wood boiler also has a good-sized loading hatch for really large chunks of wood.

  • Long service life due to the combustion chamber being made of cast iron.
  • Efficient and environmentally friendly combustion (efficiency >90%).
  • Large wood slot and considerable wood volumes.
  • Rapid start-up from cold boiler.
  • The wood boiler can withstand high pressure and is highly corrosion-resistant.