B⁴ Steel, ceramics and ceramics+

Design: Sebastian Herkner

Our latest fireplace B⁴ was designed by Sebastian Herkner, just like the B3 model. The B⁴ has a spacious combustion chamber with a large viewing panel, which gives you an unobstructed view of the beautifully calm burning fire. The B4 can be used in virtually any room thanks to its wide power range (6 kW, 8 kW and 10 kW). B⁴ Intuitive control and an extremely high build quality are given with any Bullerjan product

The B⁴ is available in three basic versions differing in look and function. Moreover, you have a wide range of interesting ways in which to adapt your B⁴ to your interior design.



  • Elegant timeless design by Sebastian Herkner
  • Large combustion chamber with large viewing window and effective window washing system
  • Three models available in distinctive different designs: Steel, Keramik, and Keramik+
  • B⁴ Steel – very slim, in classic black
  • B⁴ Keramik – elegant contemporary design, ceramic cover plate and / or tea tray optional
  • B⁴ Keramik+ – Sebastian Herkner’s interpretation of a traditional design.
  • The wide variety of colours and surface materials also allow for very modern configurations
  • And the B⁴ Keramik+ with fireclay filling, is a compact storage stove with very high storage capacity (total weight: 326 kg)
  • Individual design options through a wide choice of ceramic glazes and -surfaces
  • Optional ceramic tea-shelf (also available for B⁴ steel)
  • Choice between light or black cladding for the combustion chamber
  • Optional steel door for the wood compartment
  • Four height adjustors allow you to adjust the stove to uneven floors
  • Flue connection either at the rear or on top of theB⁴


  • Self-closing and -locking door with large viewing window
  • Simple control of the fire through precisely coordinated air supply regulation
  • Extremely solid combustion chamber made of 4 mm thick teel
  • Firebox lined with high-quality coloured vermiculite
  • Potential wear parts, can be replaced even after years, if necessary
  • External air supply connection (if required) behind or below
  • High effiency factor of 82 %
  • Energy Efficiency Class A+
  • Warranty extension (total 5 years) to the stove body on registering the product
  • Comprehensive service offering by the Bullerjan specialist dealers or Bullerjan customer service


  • Optional complete independence of room air (Raumluftunabhängig RLU) in accordance with DIBt at no extra costs making it suitable for low energy and passive houses with controlled ventilation system.
  • Proven nominal heat output of 6, 8 and 10 kW

ModellB⁴ steelB⁴ KeramikB⁴ Keramik +B⁴ Keramik + with fireclay filling
Depth45,0 cm45,0 cm45,0 cm45,0 cm
Width55,0 cm60,0 cm67,0 cm67,0 cm
Height125,0 cm125,0 cm125,0 cm125,0 cm
Total weight242 kg276 kg283 kg326 kg
Depth of combustion chamber34,5/35,0/41,0 cm34,5/35,0/41,0 cm34,5/35,0/41,0 cm34,5/35,0/41,0 cm
Exhaust gas nozzleØ 15 cmØ 15 cmØ 15 cmØ 15 cm
Air supply nozzleØ 10 cmØ 10 cmØ 10 cmØ 10 cm
Height centre exhaust
gas nozzle rear ca.
113,0 cm113,0 cm113,0 cm113,0 cm
Height centre air supply nozzle ca.14,3 cm14,3 cm14,3 cm14,3 cm
Distance rear wall / centre (top) exhaust gas
14 cm14 cm14 cm14 cm
Distance to combustible materials
to the rear
30 cm30 cm30 cm30 cm
Sides beside the stove20 cm20 cm20 cm20 cm
Sides up to 40 cm in front of the stove
50 cm50 cm50 cm50 cm
Front from viewing window120 cm120 cm120 cm120 cm
Bullerjan B4
Wertetripel bei 6 kW
Bullerjan B4
Wertetripel bei 8 kW
Bullerjan B4
Wertetripel bei 10 kW
Nominal heat capacity6 kW8 kW10 kW

Exhaust gas mass flow rate at NHO6,5 g/s7,1 g/s8,0 g/s
Mean exhaust gas temperature264 °C300 °C308 °C
Delivery pressure12 Pa12 Pa12 Pa
CO content
(bez. 13 % O2)
1250 mg/m3875 mg/m31250 mg/m3
CO content
(bez. 13 % O2)
0,10 %0,07 %0,10 %
(bez. 13 % O2)
24 mg/m325 mg/m329 mg/m3
(bez. 13 % O2)
148 mg/m3140 mg/m3120 mg/m3
OGC87 mg/m348 mg/m361 mg/m3
Efficiency82 %82 %82 %