Commissioning
Greenstar 4000 – 6 720 891 162 (2020/09)
46
Commissioning must not take place outside of the permissible pressure
range. If necessary:
▶ Identify the cause and rectify the fault.
▶ If this is not possible: isolate the device on the gas side and notify the
gas supplier.
▶ Exit the chimney sweep mode.
▶ Switch off the appliance, close the gas isolator, remove the pressure
gauge and tighten the screw.
▶ Refit the casing.
Gas pressure within the system
Combi appliances
▶ Running a hot water tap does not guarantee the appliance will
operate at maximum output throughout the test.
Natural Gas or LPG pressures.
The pressure drop from the meter or at the LPG gas supply to the gas
valve inlet test point must not be more than the values stated in table 21.
If the pressure drops are greater than shown in table 21, then this would
indicate a problem with the pipework or connections within the system.
NOTICE
▶
Do not continue commissioning until the correct gas pressure is
achieved with the appliance running at maximum output.
Table 21 Allowed mbar pressure drop
Gas supply pressure drop
Fig. 65 Natural Gas pressures
[A]
Pressure loss across the appliance
[B]
Pressure reading at inlet test point
Fig. 66 LPG pressures
[A]
Pressure loss across the appliance
[B]
Pressure reading at inlet test point
6.6
Checking the gas rate
The appliance must be running at maximum output rate when
performing the gas rate check, (
chapter 6.4.1).
▶ The gas rate should be measured at the gas meter after the appliance
has been operating for
a minimum of 10 minutes
at maximum
output.
▶ Refer to Technical data section of this manual for the appliance gas
rates and CO/CO
2
ratios.
▶ Where a gas meter is not available (e.g. LPG) the CO/CO
2
must be
checked.
▶ Gas rate must be checked with the appliance in service, maximum
output test mode.
▶ Carry out gas rating as per the latest advice in the Gas Safety
(Installation and Use) Regulations.
▶ Ensure all other gas appliances are isolated when carrying out the gas
rate check on the appliance.
▶ Set the chimney sweep mode and start up the appliance at maximum
rated output.
– Ensure that the appliance has stabilised at maximum output.
▶ Where a gas meter is not available (e.g. LPG) the CO/CO
2
must be
checked to the units shown in the setting of the air/gas ratio.
▶ If pressure and gas rate are satisfactory press
ok
or
d
and the boiler
will return to normal operation.
– If left in the service mode the control will return to normal
operation after 15 minutes.
▶ Close the gas isolation valve.
▶ Remover the manometer.
▶ Re-seal the screw in the gas inlet pressure test point.
▶ Open the gas isolation valve and ensure there are no gas leaks.
6.7
Checking for gas leaks during operation
▶ Use an approved gas sniffer or leak detection fluid to check all
connections for possible leaks. Leak detection fluid must be certified
as a gas leak testing agent.
▶ Do not allow leak detection fluid to come into contact with the
electrical components.
Gas
Type
Meter/LPG
supply
Across
pipework
Appliance
inlet
Across
appliance
[A]
Gas valve
inlet test
point [B]
Allowed mbar pressure drop
NG
19 - 23
1
18 - 22
1.5
16.5 - 20.5
LPG
32 - 45
2.5
29.5 - 42.5
1.5
28 - 41
mbar range
0010012820-001
Natural Gas
Appliance inlet
18 - 22 mbar
Meter
19 - 23 mbar
Gas Control
valve
Inlet test point [B]
1.0 mbar
drop
Across appliance
drop [A]
0010012821-001
Appliance inlet
Inlet test point [B]
L.P.G.
29.5 - 42.5 mbar
0.5 mbar drop
Regulator
LPG Storage
32 - 45 mbar
Gas Control
valve
2.0 mbar
drop
Across appliance
drop [A]
