Filling The Appliance And Adding Inhibitor; Adjusting The Operating Pressure Of The Heating System; Starting The Appliance - Bosch Condens 8300i W Installation And Maintenance Instructions Manual

Commissioning
7.2

Filling the appliance and adding Inhibitor

Before pressurising the system.
Additional expansion vessel fitted to the system.
The appliance integral expansion vessel is pre-charged to 0.75 bar. A
Schrader type valve is fitted to the expansion vessel to allow for pressure
adjustment if required.
▶ If an extra expansion vessel is fitted to the central heating system,
ensure that it is set to the same pressure as the appliance internal
expansion vessel, refer to separate instructions supplied with the
extra expansion vessel.
Filling the system - Sealed systems
NOTICE
▶ Salt based softened water must not be used to fill the central heating
system.
▶ Check drain cocks and manual air vents are closed and all radiator
valves are open. Add a suitable inhibitor or combined inhibitor/anti-
freeze, if the system is exposed to freezing conditions, to the heating
system water in accordance with the manufacturers instructions.
▶ Turn on the water main and open the system valves.
▶ Fill the system to between 0.8 and 1.7 bar via a WRAS approved
filling loop or one of the Integrated filling link accessories.
– Refer to Integrated filling link accessory instructions for
operation and use.
▶ The Automatic Air Vent will release any air trapped in the appliance.
▶ Manually vent all radiators, tighten when completed and check the
system for any leaks and correct if required.
▶ Top up the system pressure if the pressure drops below 0.8 bar.
▶ Isolate and remove filling loop connections to the system.
– Refer to Integrated filling link accessory instructions for any
further actions required after filling the system.
Filling the system - When initially filling the appliance, before power is
applied, use the pressure gauge to set the system pressure. Once the
appliance electrical pre commissioning is complete and the appliance is
switched on refer to the digital pressure display on the appliance.
The analogue pressure gauge within the appliance is for indication
purposes only, and is intended to assist when initially filling the system.
Pressure shown on this gauge should not be compared to readings
shown on the digital display as they will differ, especially when the
circulation pump is running. Final adjustments to system pressure must
be made whilst referring to the digital pressure display.
22
1.5 bar
1 bar
Min
Fig. 28
7.3 Adjusting the operating pressure of the heating
system
Pressure shown on the digital display
1 bar Minimum charge pressure (when system is cold)
1 - 1.5 bar Optimal charge pressure
3 bar Maximum charge pressure at maximum heating
water temperature must not be exceeded (pressure
relief valve opens).
Table 15
If the displayed pressure is below 1 bar when the system is cold:
▶ Top up the water until the indicator is between 1 bar and 1.5 bar
again.
If pressure is not being maintained:
▶ Check tightness of expansion vessel and heating system.
7.4

Starting the appliance

NOTICE
Damage to appliance or system!
Running the appliance:
▶ Never run the appliance when the appliance/system is empty or
partially filled.
Condens 8300i W – 6721841533 (2022/12)
Max
0010036124-001