Glow-worm Ultracom cx - Manual (Page 39)

39
Commissioning should only be carried out by a competent
person approved at the time by the Health and Safety
Executive.
12.4 Initial Lighting
NOTE: The combustion for this appliance has been
checked, adjusted and preset at the factory for operation
on natural gas (G20) as defined on the appliance data
label.
No measurement of the combustion is necessary.
Having checked :
● the appliance has been installed in accordance with the
instructions.
● the integrity of the flue system and flue seals.
● the integrity of the appliance combustion circuit and
relevant seals.
● check that all external controls are calling for heat. If
the integral programmer is fitted check that it is correctly
programmed and if necessary overridden to provide heat.
● the gas service isolation valve ‘F’, diagram 12.2, is open.
LPG Conversion:
See section 12.9.
The lighting procedure of the boiler is fully automated.
Ensure that both the central heating water temperature and
the hot water temperature control knobs are turned OFF (0).
Ensure the mains electrical supply and turn the mains reset
knob to (I) on the controls fascia.
Turn the central heating water temperature control knob to
MINIMUM.
The digital display will show water temperature in central
heating demand.
The fan should start and after a few seconds the ignition will
commence
If the burner fails to light the fan will stop. Initially this may be
due to air in the gas supply line. The boiler will automatically
have five attempts at ignition.
If necessary press the reset switch and the boiler will restart.
After the boiler has lit, allow to warm at
MINIMUM
temperature setting to purge any air from the system.
NOTE: If the appliance is operated above MINIMUM on initial
lighting, there is a possibility that the overheat lockout and
“F5” will be displayed on controls fascia, this is due to air not
having been completely purged. See diagram 12.1 for reset
button.
Once the system has been purged of air turn the Hot water
temperature control knob to the desired position and open a
hot water tap. The diverter valve motor will move to hot water
supply and the display will read system pressure. Check that
hot water is available and then close the hot water tap.
Turn the Central heating water temperature control knob to
the desired temperature.
The appliance will then continue to fire in central heating until
the user controls are satisfied or there is another demand
made for hot water.
12.5 Check the Gas Inlet Pressure and Gas
Rate
Check the supply pressure at the gas service isolation valve
test point, see diagram 12.2.
12 Commissioning
13659
The nominal supply pressure should be 20mbar (8in wg)
when the appliance is operating at the maximum heat input.
This can be achieved by turning on several hot water taps.
NOTE:
There is a pressure drop over the gas service isolation
valve prior to the inlet pressure test point, this is normal and
the inlet pressure to the main gas valve can be up to 2mbar
less than the supply pressure to the boiler at the maximum
heat input. Additionally the safe nominal maximum heat input
of the appliance can be achieved at an inlet pressure down to
15mbar.
The gas valve is factory set for natural gas (G20) and should
need no adjustment.
Should any doubt exist about the gas rate, check it using the
gas meter test dial and stop watch, at least 10 minutes after
the burner has lit, see table below, for approximate rates.
Make sure that all other gas burning appliances and pilot
lights are off.
It should be noted that the appliance will modulate the heat
input according to demand. This may affect the gas rates
measured if the appliance reaches its operating temperature
during the measurement.
Turn taps off and disconnect the pressure gauge.
Operational Gas Inlet Pressure
With ALL other gas appliances operating, check the
operational supply pressure at the gas service isolation valve
test point, see diagram 12.2.
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.
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.
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. Reset the boiler.