Checking Gas Inlet Pressure; Checking The Gas Supply Pressure - Bosch Condens 8300i W Installation And Maintenance Instructions Manual

Commissioning
7.7

Checking gas inlet pressure

7.7.1

Checking the gas supply pressure

▶ Switch off the appliance and close the gas isolator.
▶ Unscrew the screw on the test point for the gas supply pressure and
connect a pressure gauge.
T10
Fig. 33 Gas valve test points (above: SIT valve, below: Honeywell valve)
▶ Open the gas isolator and switch on the appliance.
▶ Ensure that there is heat transfer by opening the radiator valves and
zone valves.
▶ Set the chimney sweep mode and start up the appliance at maximum
rated output.
▶ Check the required gas supply pressure according to table 14.
Commissioning must not take place outside of the permissible pressure
range.
▶ Identify the cause and rectify the fault.
▶ If this is not possible: isolate the appliance on the gas side and notify
the gas supplier.
If the operating inlet pressure cannot be achieved there may be an issue
with the gas supply meter (NG), cylinder regulator (LPG), or pipe sizing
(Ref AS/NZS5601). This must be resolved before proceeding.
▶ Exit the chimney sweep mode.
▶ Switch off the appliance, close the gas isolator, remove the pressure
gauge and tighten the screw.
26
▶ Check for gas tightness.
Fig. 34 Refit combustion casing
▶ Refit the combustion casing.
▶ Ensure this cover is engaged onto top bracket [1] before securing
screw [3].
Gas pressure within the system
0010024761-002
The appliance must be running at maximum output rate when
performing the gas rate check ( chapter 7.5).
Combi appliances
▶ Running a hot water tap does not guarantee the boiler will operate at
maximum output throughout the test.
Gas type
NG (23)
LPG (propane)
LPG (butane)
1) Standard figure for LPG with fixed cylinders with capacities up to 15 000 l
Table 14 Permissible gas supply pressure
If the pressure drops are greater than shown below, then this would
indicate a problem with the pipe work or connections within the system.
NOTICE
Do not continue commissioning until the correct gas pressure is
achieved.
1.
3.
Design Permissible pressure range at
pressure maximum rated output
[mbar]
[mbar]
11.3 11 – 30
1)
27.5 25 – 45
27.5 25 – 35
Condens 8300i W – 6721841531 (2022/10)
2.
0010023566-001
[kPA]
1.1 – 3.0
2.5 – 4.5
2.5 – 3.5