HAMWORTHY HEATING LTD
MILBORNE 500 SERIES
500001130/A
32
15.3.8 The gas valve throttle setting can now be
regulated. This is a condition of the flue gas
combustion analysis rather than a fixed pressure.
Check the CO2 values in accordance with table
15.1. If the CO2 values are incorrect then
adjustment must be made by adjusting the gas
valve throttle screw. Turning the throttle screw
anticlockwise increases the air flow and reduces the
CO2 value. Turning the throttle clockwise decreases
the air flow and increases the CO2 value. See fig
15.3.8.
Note: To increase the air flow turn the screw anti
clockwise, to decrease the air flow turn the screw
clockwise.
15.3.12 Ensure that the combustion settings are still
correct at maximum output and if necessary repeat
stages 15.3.7 to 15.3.12 until the settings are
correct.
Fig 15.3.8 - Air Flow Adjustment
15.3.9 Allow the boiler to stabilise at maximum
power and if necessary readjust the gas flow rate.
15.3.10 Reduce the boiler power to minimum by
pressing switch S5 on the control panel.
The first digit of the display will indicate the fan
speed. L = minimum speed.
15.3.11 The gas flow rate can now be regulated.
This again is a condition of the flue gas analysis
rather than a fixed pressure. Check the CO2 values
in accordance with table 15.1. If the CO2 values are
incorrect then adjustment must be made by
adjusting the gas valve offset adjustment screw.
See figure 15.3.11. Turning the offset screw
anticlockwise increases the gas flow and increases
the CO2 value. Turning the offset clockwise
decreases the gas flow and decreases the CO2
value. See fig 15.3.11.
Note: To increase the gas flow turn the screw
anti clockwise, to decrease the gas flow turn the
screw clockwise.
Fig 15.3.11 - Gas Flow Adjustment
Gas Max
Output
Min
Output
Natural Gas
C02 9.2 - 9.4%
C02 8.3 - 8.5%
L.P.G.
C02 10.2 - 10.4% C02 8.6 - 8.9%
Table 15.1: Flue Gas Analysis C02 Readings
15.3.13 The individual boiler module is now
commissioned. If there are further modules to be
commissioned then switch the commissioned
module off using the external thermostatic controls
or time clock to ensure correct shutdown. Further
modules may now be commissioned individually by
following procedure detailed and used for the first
module.
15.3.14 Once all modules have been commissioned
switch all modules to the ‘on’ position and take a
dynamic gas inlet pressure test reading to ensure
that the gas supply is sufficient for full operating load
conditions. This should be taken at all boiler
modules to ensure the supply is satisfactory at all
boilers.