Glow-worm Ultracom2 cxi - Manual (Page 29)

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INSTALLATION
12.6 Gas rates
The supply from the governed meter must be of adequate size
to provide a steady inlet working pressure of 20mbar (8in wg) at
the boiler.
• On completion, test the gas installation for tightness using
the pressure drop method and suitable leak detection fluid,
purge in accordance with the above standard.
i 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.
• Activate the test mode "P.01" and set the value to 100 in
order to force the burner at P. max. See chapter "Specific
adjustment ► Appliance technical settings and parameter list
► Test modes".
12.6.1 Operational Gas Inlet Pressure
1
2
Key
1 Gas service isolation valve
2 Test point
• With all other gas appliances operating, check the
operational supply pressure at the gas service isolation valve
test point.
The nominal supply pressure for Natural Gas (G20) is 20mbar.
The nominal supply pressure for LPG (G31) is 37mbar.
• 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.
i The burner pressure cannot be measured and is not
used to measure the gas rate.
12.6.2 Gas Rate
• Make sure that all other gas burning appliances and pilot
lights are off.
• 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.
• Gas rates for both central heating and hot water can be
verified using the test program P.03 and P.01 respectively.
Gas rates (G20) Gas rates (G31)
(approx) after 10 mins from cold
Model
MIN MAX MIN MAX
m 3 /h ft 3 /h m 3 /h ft 3 /h kg/h kg/h
24cxi 0.54 19.07 2.70 95.35 0.40 1.98
30cxi 0.65 22.95 3.24 114.42 0.47 2.38
35cxi 0.95 33.55 3.77 133.14 0.68 2.77
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, press the "reset" button to reset the boiler.
12.7 Testing heating system
• Ensure that the external controls and programmer are calling
for heat.
• Fully open all radiator valves, see chapter "Appliance
installation ► Recommendations before installing ► Heating
circuit design".
• Activate the C.H. function on the appliance's control panel.
• Balance the radiators as required to give the required system
differential.
• Turn off all radiators that can be shut off by the user and
check to see if less than the maximum differential allowed of
20°C can be achieved across flow and return.
i Should the appliance require adjustment refer to the
"Specific adjustment" section overleaf.
• Allow the system to reach maximum temperature then switch
off the boiler by isolating from the electrical supply.
• Drain the entire system rapidly whilst hot, using the drain
taps at all the low points of the system. Fill and vent the
system as described previously in chapter "Commissioning
► Filling the CH system (Central heating)".
• Adjust the boiler temperature controls and any system
controls to their required settings.
12.8 Testing domestic hot water system
• Open a hot-water tap.
• Check that the temperature obtained is compliant with the
setting on the appliance.
12.9 Completion
• Ensure that the magnetic lighting instruction label is placed
on the surface of the boiler casing.
GB: It is a requirement that the “Benchmark” Installation,
Commissioning and Service Record is completed and left with
the user.
IE: it is necessary to complete a “Declaration of Conformity” to
indicate compliance to I.S.813. An example of this is given in
the current edition of I.S.813.