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Note: Product Title reflects this boiler's IBR Net Output Rating.

This new combi boiler is identical to the Greenstar Combi 100 boiler (ZWB28-3) except with the CRC200 thermostat, DHW tank sensor, supply sensor, expansion tank and twin pipe vent adapter removed. These combi boilers provide both space heating and domestic hot water, while maintaining AFUE efficiencies of 95.0%.

All Greenstar Combi boilers are equipped with a high-strength stainless steel secondary exchanger and burner with double passage - ensuring consistent temperature output based on demand. The DHW hot water temperature control limit of 140°F helps prevent scale build-up within the heat exchanger.

Other features with this new boiler include a new electrical connection with a pre-wired 120V main power cable and plug. A new LP conversion kit which is easier to field convert the boiler. New Part number: 7738100825. All Bosch Greenstar boilers come with a Lifetime Limited warranty on the heat exchanger and a 5 year warranty on parts and labor.

  • Provides heat and up to 4gpm domestic hot water in one compact, lightweight wall-mounted unit.
  • Single zone utilizes boiler pump, multi-zone requires a primary/secondary piping or low loss header
  • Can be installed using a variety of venting materials and terminations

    This is a "P" (project) boiler and is a stripped down boiler. Typically purchased in bundles for larger jobs
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Manuals (2)
Vent Type:

Direct Vent

Fuel Type:

Natural Gas



BTU Input:


IBR Rating:


DOE Rating:



High Efficiency

Combo DHW


System Type:

Hydronic (Water)

Height (Inches):


Depth (Inches):


Width (Inches):


Weight (lbs):

125 lbs


Limited 5 Year Parts & Labor/Lifetime Warranty on Heat Exchanger

Energy Star Rated:



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