Bosch tankless water heater manuals are listed below under the heading "ATTACHMENTS". The vent pipe requirements and manufacturers specs are under the"Venting" section of the manual.
*Please note that each model has parameters as to the minimum and maximum venting length and number of elbows that can be used.
* The use of an additional condensate drain is required for the Bosch 250,635 and 2400 series as stated in a recent technical bulletin published by Bosch (PDF attachment below) Cinnabar Equipment stocks 3 options for this requirement, a Vertical In-Line, Horizontal and Vertical Condensate Tee.