Before Operating The Appliance; Switching The Appliance On/Off; Switch On Heat - Bosch Greenstar Series Installation And Service Instructions For Contractors

8.1

Before operating the appliance

NOTICE
Commissioning without being properly filled and purged will
damage the appliance.
▶ Only operate this appliance after ensuring there is sufficient water in
the boiler and the system.
▶ Adjust the expansion vessel pre-charge pressure to the static head of
the heating system ( page 31).
▶ Open radiator and zone valves (as applicable).
▶ Open heating supply and return valves, fill heating system to 14.5 to
21.75 psi (1 - 1.5 bar) and close fill valve.
▶ Bleed all air from the system.
▶ If the boiler water pressure has dropped, fill the heating system again
to 14.5 to 21.75 psi (1 to 1.5 bar).
▶ On ZBR...-3A appliances (heating boilers) with a DHW tank, open the
cold water supply and open a DHW tap until water runs out.
▶ Verify that the gas type specified on the rating plate is the same as the
gas type used.
▶ Open the gas cock.
8.2

Switching the appliance ON/OFF

Startup
▶ Switch the appliance ON using the ON/OFF switch.
The display indicates the supply temperature of the hot water in °F. If
necessary, convert to °C ( page 60).
Fig. 63 Switching the appliance ON/OFF
When the appliance is switched ON for the first time, it performs a once-
only purging sequence. This involves the heating zone pump switching
on and off at intervals (for approx. 4 minutes).
The display shows in alternation with the supply temperature.
▶ Open the automatic vent [9] (only ZWB...-3A) and close it again
when the purging sequence has finished ( page 50).
If the display shows in alternation with the supply temperature, the
trap filling function is active ( page 59).
Shutdown
▶ Switch appliance OFF using the ON/OFF switch.
The display goes out.
▶ If the appliance is taken out of service for a longer period: Observe
frost protection ( Section 8.9).
Greenstar – 6721822579 (2021/01)
8.3

Switch on heat

Set the maximum supply temperature based on the structure's heat loss
on design day.
Boiler high Typical supply
limit dial temperatures
1 approx. 95 °F (35 °C)
2 approx. 109 °F (43 °C)
3 approx. 122 °F (50 °C) Radiant floor heating system
4 approx. 140 °F (60 °C) Panel radiator system
5 approx. 153 °F (67 °C) Cast iron radiator system
6 approx. 167 °F (75 °C)
max approx. 187 °F (86 °C) Baseboard and convector
Table 22 Typical supply temperatures
With radiant floor heating, limit the maximum permissible supply
temperature as recommended by the manufacturer.
▶ In order to set the maximum supply temperature, turn the supply
temperature dial knob.
4
3
2
1
Fig. 64 Switch on heat
If the burner is operating, the burner operation indicator lamp is
illuminated.
Commissioning
Sample application
Frost protection
system
reset
eco
3 4
e
5 2
6 1 6
max min max
6 720 641 933-53.2O
51