Heating boilers


Compact, quiet and perfect for both new build and renovation projects. It combines high efficiency and low emissions with a wide range of practical benefits.

  • NOx emissions below 40mg/kWh
  • Efficiency (NCV) up to 110.4% at 40/30 degrees celsius
  • Suitable for use with a wide range of controllers (RC35, EM10, MCM10, 8000 Series)
  • Suitable to use with a balanced flue arrangement
  • Simple commissioning and maintenance
  • Fully modulating pre-mix burner
  • Maximum operating pressure of 6 bar
  • Extremely quiet, operates at 60dB(A) at full load
  • Transport weight (depending upon output) 410kg to 520kg
  • Able to control fully modulating primary pumps – maximising condensing benefits
  • Available in 5 outputs the GB402 high efficiency commercial boiler with up to 110% efficiency (NCV).
  • Ideal for single or multiple boiler installations in medium to large buildings, including schools, hotels, care homes, offices and commercial buildings.
  • This boiler must be installed in a sealed system. Bosch Commercial and Industrial supply a range of system separation Plate Heat Exchangers to aid sealed system installations.
  • Servicing and Maintenance: The GB402 is designed to minimise installation time and effort, and, in the long run, its efficient construction ensures minimised operating costs. The factory-fitted gas-fired burner is tested and set up for optimal and clean combustion. Servicing is also simple. Large inspection apertures make access to components particularly easy and all internal components can be easily cleaned or replaced if necessary.
  • Performance and Design: The GB402 has been developed to achieve lower running costs, a reduced carbon footprint and low NOx emissions. This is achieved through the use of a powerful, lightweight and fully insulated cast aluminium heat exchanger. The clean burning, pre-mix burner and intelligent combustion controller enable the GB402 to operate in a wide modulation range of between 20% to 100%, with efficiency up to 110% (NCV).