Bosch Installation Manual

Product Description

Greenstar – 6721822579 (2021/01)

Key to Fig. 8:

[1] Ignition transformer

[2] Boiler high limit dial

[3] 120 VAC connection

[4] External heating pump for unmixed heating circuit (secondary

circuit) 4 or DHW recirculation pump

[5] Fuse T 6.3 A (120 VAC)

[6] DHW thermostat

[7] External safety high limit or low water cut off (LWCO)

[8] BUS connection, e.g. heating control

[9] Room thermostat – dry contact

[10] Outdoor temperature sensor

[11] Code plug

[12] Diagnostic interface

[13] ON/OFF switch

[14] Gas valve

[15] Fan

[16] Flue gas temperature limiter

[17] Supply temperature sensor

[18] Flame rod electrode

[19] Ignition electrode

[20] Boiler block temperature limiter

[21] DHW temperature sensor

[22] Boiler circulator

[23] 3-way valve (Space heating/DHW heating)

[24] Flow meter (turbine)

[25] Additional supply temperature limiter

[26] External system supply temperature sensor

1) Set the service function 5.E,  page 56.