Brand: Bosch
Product Code: ZWB35-3
Availability: In Stock


Bosch ZWB35-3 Greenstar Combi 131 - 117K BTU - 95.0% AFUE - Combi Gas Boiler - Direct Vent (ZWB35-3, Unico)

Bosch ZWB35-3 Greenstar Combi 131 - 117K BTU - 95.0% AFUE - Combi Gas Boiler - Direct Vent


  • The Bosch greenstar boiler brings today's high efficiency technologies together in a single package.
  • Astounding efficiency ratings can be achieved with the use of Bosch's condensing technology, squeezing every last BTU out of your home's gas supply.
  • An included 3-speed Grundfos pump and a wide variety of pipe venting options allow the boiler to be installed in nearly any home imaginable.
  • This boiler includes a domestic hot water coil, allowing the boiler to act as a tankless hot water heater as well as a hydronic boiler.

General Features:

  • Includes CRC200 Programmable Comfort Room Controller
  • Aluminum-Silicon heat exchanger delivers high efficiency - 95% with low temperature applications
  • Low NOx emissions ahead of 2012 SCAQMD regulations
  • Simple, intelligent control options optimize efficiency and fuel consumption
  • Low electrical consumption when the boiler is in standby mode
  • Electronic ignition
  • Anti-cycle and modulation control
  • Limited lifetime heat exchanger and 5-year parts & labor warranty
  • All models available as NG or LP
  • Special insulation ensures ultra-quiet operation
  • Compact dimensions and built-in frost protection offer flexibility for location of installation
  • ECO mode for energy saving fuel consumption
  • Exclusive safety feature - keypad safety lock prevents unwanted tampering with the heating controls

Al-Si heat exchanger:

  • Each unit features an ASME approved Al-Si heat exchanger constructed of advanced Magnesium-Aluminum-Silicon alloy - offering increased flexibility versus traditional stainless steel.
  • They are equipped with highly durable heating blocks that are corrosion resistant and designed to optimize clean burning combustion over an extra large surface area, which requires minimal servicing and reliance on spare parts during the boiler’s lifetime.

Full modulating fan assembly:

  • A full modulating fan automatically increases or decreases its speed according to the amount of gas coming into the boiler depending on the heat demand.
  • This process, called modulation, prevents the boiler from either having too little or too much air in the unit for optimal combustion - ensuring high efficiency.

The Unico System uses less than one-third of the space in the built environment than a traditional system. It can deliver up to 9 tons of air conditioning in the same space as a 3-ton traditional unit.

Technical Specifications
Amps 15
BTU Input 36000-131900
BTU Output 118000
Composition Powder-Coat Steel cabinet
Connection DHW & DCW 3/4" NPT, HTG SUPPLY & RETURN 1" NPT
Efficiency 96%
Electrical Voltage 120 VAC / 60 Hz / 1 P
Equipment Type Boiler
Finish White
Fuel Type Natural Gas or LP
Gas Connection Type 3/4" [19.05 mm] N.P.T.
Ignition Type Hot Surface (HSI)
System Type Hydronic (Water)
Temperature range 100°F to 140°F (37.78°C to 60°C)
Vent Type Direct Vent
Weight 110.2 lbs.
Height 33.4688"
Width 17.3281"
Depth 13.8906"
Brand Bosch
Air Discharge Direction Horizontal / Vertical