- 40 -
INST
ALLA
TION
COMMISSIONING
Any variation in gas supply pressure or
flue length may result in the customer
experiencing a harmonic noise from the
boiler.
In these circumstances, it may be neces-
sary to reset the burner gas pressures in
accordance with section 11 Gas Valve of
the Service Manual.
It should be noted that a Flue Gas Ana-
lyser is required for this procedure.
Checking the inlet pressure
Fig. 7.7
35
• Remove the front panel of the case (see
section "Dismantling the external panels"
to page 46) and lower the control panel
(see "Electrical connections" to page 31).
• Loosen the internal screw on the Inlet
Pressure Test Point 35 (Fig. 7.7) on the
Outlet Pressure Test Point of the Gas
Valve and connect a pressure gauge us-
ing a suitable hose.
• Open the gas inlet valve (11on page 8).
• Turn on the electricity supply to the boil-
er, switching on the fused spur isolation
switch. The appliance operation light 9 will
flash every 4 seconds.
• Set the function knob 7 as illustrated in
Fig. 7.8.
Fig. 7.8
9
7
6 5
• Read the inlet pressure value and ensure
that it is within the limits given in the ta-
ble Gas supply pressures, in the sections
"Technical Data" on pag. 18.
If it does not comply with the required
pressure check the gas supply line and
governor for faults and/or correct adjust-
ment.
Where the boiler is connected to a gas
supply which has a zero set governor
then it is necessary under the Gas Safety
(Installation and Use) Regulations 26.9.
to perform a combustion analysis test
for CO/CO
2
(The limits for the boiler is
given in section 4.3 and 4.4 Technical
data:CO
2
contents /Other flue gas fig-
ures) and complete the Certificate of Ex-
emption section of the Benchmark.
• Switch off the boiler
close the gas inlet
valve
.
• Disconnect the pressure gauge and close
the Inlet Pressure Test Point 35 (Fig. 7.7).
Important: after the checks all of the test
points must be sealed.
