Checking Gas Inlet Pressure; Checking The Gas Supply Pressure - Worcester GR8700iW 35 C Installation And Maintenance Instructions Manual

Commissioning
6.6

Checking gas inlet pressure

6.6.1

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. 63 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
by running a hot tap.
▶ Set the chimney sweep mode and start up the appliance at maximum
rated output.
▶ Check the required gas supply pressure according to table .
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.
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▶ Exit the chimney sweep mode.
▶ Switch off the appliance, close the gas isolator, remove the pressure
gauge and tighten the screw.
▶ Check for gas tightness.
Fig. 64 Refit combustion casing
▶ Refit the combustion casing.
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▶ Ensure this cover is engaged onto top bracket [1] before securing
screw [3].
Gas pressure within the system
The appliance must be running at maximum output rate when
performing the gas rate check, ( chapter 6.4).
Combi appliances
▶ Running a hot water tap does not guarantee the boiler will operate at
maximum output throughout the test.
Refer to the figures below for natural gas or L.P.G gas pressures.
The pressure drop from the meter or at the L.P.G. gas supply to the gas
valve inlet test point must not be more than:
• 40 kW or below (≤ 40 kw): 2.5 mbar for Natural Gas
• above 40 kW (> 40 kw): 3.5 mbar for Natural Gas
• 4 mbar for L.P.G.
1.
3.
Greenstar 8000 Style – 6720883864 (2019/02)
2.
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