Boiler Information

Large Commercial / Grain Drying

The M-1 range of boilers are Kalvis’ premium commercial boilers.  They have been specifically designed to offer the customer high output, low maintenance and fuel tolerance.  The majority of our larger systems are based on the M1 range.

M1 boilers are ideal for large industrial applications, with a wide range of accepted fuels, including grain waste, saw dust, wood chips and pellets.


  • Economical and environmentally friendly
  • Automated control of combustion process
  • Boiler operates with fuel storage and fuel supply equipment
  • Moving fire grate spreads fuel evenly and moves it through the combustion chamber

Small Commercial / District Heating

The majority of our district heating/small scale commercial systems are based around Froling’s TX, T4, P4 and S4 boilers.

Froling wood chip and pellet boiler, TX

The TX is a reliable and user friendly range, that can efficiently handle wood chip and wood pellets using a well-designed and robust automated system.


  • Ventilated step grate
  • Smart grate technique
  • Ash removal screw
  • High temperature combustion chamber with firebrick lining
  • Standing tubular heat changer with efficiency optimisation system
  • Lambdatronic H3200 controller

Froling wood chip and pellet firing T4

The T4 range is a compact, fully automated system, with optimum energy consumption to provide reliable heating


  • Simple on-site assembly
  • Smart Grate Technique
  • Perfect combustion control
  • High-temperature combustion chamber
  • Quick clean
  • Upright heat exchanger
  • Lambdatronic H3200 control system

Froling S4 Turbo Firewood Boiler

The S4 turbo allows you to burn larger pieces of firewood up to half a metre long.  The robust construction and use of silicon carbide allows for long life at high temperature.


  • Expanded fuel loading chamber
  • Unique automatic heat up
  • High temperature swirl combustion chamber
  • Series WOS system
  • Speed regulated induced draught fan
  • Specialised carbonisation gas extraction system
  • Lambdatronic S 3200 control system

Froling P4 Pellet Boiler

The P4 range is essentially “plug and play” with partially installed components and wiring, allowing easy use and guaranteed low emissions.


  • Plug and play
  • Multi-layer heat exchanger
  • Self-cleaning system
  • Energy Efficiency
  • Speed-regulated induced draught fan
  • Room air-independent operation
  • Lambdatronic P 3200 touch control

Extensive safety concepts

Domestic / Small Commercial

We can offer the Kalvis K-10 boiler on a supply-only basis. The K-10 is a gas generation, manual loading boiler.


  • MCS accredited to be Domestic RHI compliant
  • Sleek elegant design of the Kalvis K-10 provides cost effective heat for your home
  • Burns logs or other solid biomass fuel
  • Easy and hassle free to use
  • Ties in with any existing wet system
  • Ability to burn pellets in the system – making the system fully automatic – (Pellas Pellet Head to be purchased separately)

Boiler Partners

Kalvis is one of the largest metal processing companies in Lithuania.  With a large team of skilled and experienced designers and technologists, they are dedicated to providing innovative products, and improving heating systems worldwide.

Kalvis provide the industry with over 100 types of boilers, which include domestic boilers and stoves, automated boilers, and large industrial boilers.  All products are tested and improved in their boiler testing centre to provide customers with highly efficient and coordinated systems.

Froling is a premium Austrian boiler manufacturer with 5 decades of experience with biomass.  They offer an efficient, complete heating solution, from fuel storage down to control systems.  The idea of providing a complete solution allows the system to be perfectly coordinated, in turn saving energy and costs.