Checking The Gas Rate; Gas Rating Test; Checking For Leaks During Operation - Worcester Greenstar CDi Compact Installation, Commissioning And Servicing Instructions

COMMISSIONING
≈ ≈
5 s 5 s
eco
°C
reset ok
°F
Max
1.
e
min max
Fig. 63 Setting boiler to maximum
▶ Check the gas supply working pressure at the gas valve conforms to
values shown in Fig. 64 or Fig. 65 .
▶ Press the button to return to normal operation.
ok
▶ The boiler will run for 15 minutes in service mode and return to normal
if no other inputs are made.
Ensure that the inlet pressure is satisfactory with all
other gas appliances working.
After the tests are completed:
▶ Disconnect the manometer.
▶ Retighten, but do not overtighten the inlet pressure test point screw.
GAS PRESSURE WITHIN THE SYSTEM
Refer to the figures below for natural gas or L.P.G gas pressures.
The working pressure at the boiler must not be less than the working
pressure read at the meter minus 1mbar for natural gas or minus
2.5mbar for L.P.G.
The pressure drop from the meter to the gas valve must not be more than
2.5mbar for natural gas or 4mbar for L.P.G.
If the pressure drop is greater than shown below, then this would
indicate a problem with the supply pipe work which must be rectified.
Meter
Natural Gas
19 - 23 mbar
Boiler inlet
1 mbar
drop
18 - 22 mbar
Fig. 64 Natural gas pressures
34
2
1 1 3
0 bar 4
1
min max
°C
°F
Max
Gas Control
valve
16.5 - 20.5 mbar
1.5 mbar
drop
6720644744-44.1Wo
Regulator
L.P.G.
32 - 45 mbar
Boiler inlet
2.5 mbar
drop
29.5 - 42.5 mbar
Fig. 65 L.P.G. pressures
NOTICE:
Do not continue commissioning until the correct gas
pressure is achieved.

5.5.2 CHECKING THE GAS RATE

▶ The gas rate should be measured at the gas meter after the boiler has
been operating for a minimum of 10 minutes at maximum output.
▶ See Technical data section on page 8 of this manual for gas rates and
CO/CO ratios.
2
▶ Where a gas meter is not available (e.g. L.P.G.) the CO/CO
checked.

5.5.3 GAS RATING TEST

▶ Ensure all other gas appliances are isolated.
1. Set the boiler to maximum output by pressing
together for at least 5 seconds.
The chimney sweep symbol (1) will be displayed at the top of the
screen and the word "Max" will flash at the bottom of the screen. The
boiler will ramp up to maximum output in 30 to 35 seconds.
≈ ≈
5 s 5 s
eco
°C
reset ok
°F
Max
1.
e
min max
Fig. 66 Setting boiler to maximum
▶ Ensure that the boiler has stabilised at maximum output.
▶ Carry out Gas rating procedures as described in "Essential Gas
Safety" third edition.
▶ If pressure and gas rate are satisfactory press the
boiler will return to normal operation.
– If left in the service mode the control will return to normal operation
after 15 minutes.

5.5.4 CHECKING FOR LEAKS DURING OPERATION

▶ Use an approved leak detector to check all connections for possible
leaks. The product must be certified as a gas leak testing agent.
Gas Control
valve
28 - 41 mbar
1.5 mbar
drop
6720644744-45.1Wo
must be
2
and the button
eco
2
1 1 3
0 4
bar
1
min max
°C
°F
Max
button and the
ok
6 720 803 800 (2012/11)