Bosch Appliances manual System 6 Greenstar Combi Boiler in a single zone system, Summary

Applications Manual Bosch Greenstar 33

2.6System 6: Greenstar Combi Boiler in a single zone system

Summary:

Single combi-boiler supplying one heating zone. Outdoor reset with FW200 controller with built-in room sensor mounted in the living space for room feedback. DHW generation directly off the boiler through the tankless heat exchanger. This system is using the boiler pump for zone water circulation.

The “combi” or combination boiler is a high efficiency central heating boiler and water heater combined within one compact unit. Water is heated on demand directly from the water main eliminating the need for a hot water storage tank.

Single boiler with primary/secondary piping configuration supplying one heating zone. Outdoor reset with FW200 controller and room sensor mounted in the living space for room feedback.

Use this design where System 2 cannot be used due to too great a system pressure drop. Primary/secondary piping is also required for radiant floor and panel radiator applica- tions.

Primary/secondary piping isolates the system flow from the boiler flow and prevents the system from influencing boiler performance.

In detail:

The FW200 is an outdoor temperature based controller with room temperature influence. The controller adjusts the heating curve (boiler supply temperature) according to outdoor temperature. When the FW200 is wall mounted as a room sensor, it uses room temperature to adjust the heating curve and modify boiler supply temperature ac- cordingly.

FW200 provides warm weather shutdown.

For temperature sensitive radiant floor applications, install a thermostatic tempering valve for overheat protection.

Required components:

Greenstar combi-boiler.

FW200 controller in the room.

Primary/secondary piping and system pump.

Thermostatic mixing valve (optional - overheat protection for temperature sensitive floors).

Additional instructions:

See manufacturer’s installation and operating instructions.

Install an adequately sized Pressure Relief Valve (PRV) on the DHW outlet of the combi boiler.

To reduce the risk of scalding it is recommended to install a DHW tempering valve.

The Greenstar combi boiler is equipped with an internal

3.17gal (12 liter) expansion vessel. The installation manual provides information on how to determine if it is of sufficient capacity for the application or if an additional expansion vessel is needed.

Bosch Thermotechnology Corp. Data subject to change