Domestic Hot Water Recirculation With External Pump - Bosch Greentherm T9800 SEC 199 Installation And Operating Instructions Manual

4.11 Domestic hot water recirculation with
external pump
The following drawing is provided to illustrate one possible
recirculation design. This schematic is for illustration only and
must not be used for actual Installation without appropriate
engineering and technical advice from a properly licensed
professional in the locality where the installation is made.
This appliance has been designed to permit recirculation by
controlling an external pump. For this function, the external
pump must be electrically connected to the appliance - Bosch
cable accessory (7736504585) is available. All the features of
recirculation ( 6.5.2, A1 Recirculation) can be used.
Fig. 30 Recirculation application with a dedicated return
line
[1] Cold water supply
[2] Check valve, field supplied
[3] Circulator pump, field supplied
[4] Expansion tank, field supplied
[5] Circulator cable accessory
[6] Greentherm T9800 SE / SEC
[7] PRV
[8] Shutoff valves, field supplied
Greentherm T9800 SE 160/199 | SEC 199
Fig. 31 Recirculation application using the cold water line
and a cross-over valve
[1] Cold water supply
[2] Check valve, field supplied
[3] Expansion tank, field supplied
[4] Circulator pump, field supplied
[5] Circulator cable accessory
[6] Greentherm T9800 SE / SEC
[7] PRV
[8] Shutoff valves, field supplied
[9] Cross-over valve, field supplied
Recirculation application showed in fig. 31 is
for Greentherm T9800 SE model only.
Models with a built-in pump cannot be used.
4.11.1 Recirculation options
House Recirculation
This recirculation option uses the appliance's NTC sensor along
with the optional schedule to control the pump.
Tank loading
This recirculation option gives the option of using one of three
temperature sensors to control the recirculation option. The
scheduling option is not available for tank loading, except for
commercial models.
• External NTC - 7 736 504 583
– Only compatible with Bosch cable/sensor accessory
(7736504583).
• Aquastat - 7 736 504 584
– The aquastat connector kit (7736504584) must be
used to connect a field supplied aquastat to the
appliance.
Installation instructions | 35
6 720 816 815 (2018/08)