- 3 -
LPG MODELS - ONLY
Please refer to the specic instruction relating to your
model and check/adjust the CO2 value, refer to table
overleaf.
Gas valve setting
All gas valves are tested and factory set during manufac-
ture.
It should not be necessary to adjust the gas valve.
NOTE: Safe combustion can only be verified by measuring
CO/CO2 ratio. This must not exceed the value shown in
the table overleaf.
● Shut down boiler.
● Connect a CO2 analyser to the combustion test point.
● Start the boiler.
● Press the «Mode» and «-» buttons simultaneously, the
letter “L” is displayed and the boiler is now running at low
gas ow rate. Allow the boiler to run for a few minutes to
stabilise, refer to the CO2 setting table and check that the
CO2 value is to specication, if adjustment is required,
proceed as follows.
NOTE: The adjustment should be made in 1/8 of a turn
increments, waiting 1 minute to allow the appliance to
stabilise.
● To adjust the CO2, remove protective cap (b) from the
gas valve. Carefully turn the gas valve adjuster until the
correct CO2 value is obtained according to table minimum
column.
● Press the «Mode» and «+» buttons simultaneously the
letter H is displayed and the boiler is now running at high
gas ow rate.
● Allow the boiler to run for a few minutes to stabilise and
check the CO2, refer to the CO2 setting table and check
that the CO2 value is to specication.
● Check the CO/CO2 combustion ratio does not exceed
the value in the table overleaf.
If the CO2 or CO/CO2 combustion ratio are not as
specied please refer to the “Completion” paragraph of
these instructions.
Check the Gas Inlet Pressure and Gas Rate
On completion, test the gas installation for tightness using
the pressure drop method and suitable leak detection uid,
purge in accordance with the above standard.
NOTE: Due to the modulating operation of the boiler and
the need to check the gas inlet pressure and measure the
gas rate at maximum rate, it will be necessary to force it to
maximum.
Operational Gas Inlet Pressure
With ALL other gas appliances operating, check the
operational supply pressure at the gas service isolation
valve test point, refer to your Installation literature supplied
with your appliance.
The nominal supply pressure for Natural Gas (G20) is
20mbar.
Turn the taps and appliances off, then disconnect the
pressure gauge.
Additionally the safe nominal maximum heat input of the
appliance can be achieved at an inlet pressure down to
15mbar.
NOTE: The BURNER PRESSURE cannot be measured
and is not used to measure the gas rate.
Gas Rate
Make sure that ALL other gas burning appliances and pilot
lights are off.
NOTE: Press the «Mode» and «+» buttons simultaneously
the letter “H” is displayed and the boiler is now running at
high gas ow rate.
Allow the boiler to run for a few minutes to stabilise and
check the CO2.
Check the gas rate using the gas meter test dial and stop
watch, at least 10 minutes after the burner has lit, see
table below for approximate rates.
In communal or LPG installations where the gas rate
cannot be measured it is acceptable to measure the
combustion rate as described in the servicing section.
On completion, reset the boiler to normal operation by
referring to the Installation and Servicing Instructions.
Completion
If it is not possible to achieve the required results for
either the combustion or gas rates, it will be necessary to
complete a full service of the appliance and then repeat
the combustion check procedure. If after servicing and
adjustment of the appliance the combustion values are still
unacceptable and after further remedial work has been
carried out, the appliance must be disconnected until the
CO/CO2 ratio is acceptable. Advice can be sought from
the Saunier Duval Technical Helpline 01773 828400.
