Initial Lighting - Glow-worm Ultracom 38cxi Installation And Servicing

12.4 Domestic Water Circuit
Open all hot water taps in turn then close when water flows.
Check for water tightness of the complete domestic water
system.
The domestic hot water flow has a restictor, factory fitted,
which reduces the flow to a maximum of, 8.0 l/min for 24cxi,
12.0 l/min for 30cxi and 15.5 l/min for 38cxi.

12.5 Initial Lighting

The lighting procedure of the boiler is fully automated.
The boiler is delivered in the "OFF" condition and the
24hr. CH programmer is enabled with the factory pre-set
timed intervals of:
ON 6.00 - OFF 8.00
ON 16:00 - OFF 23.00
The DHW pre-heat will also be enabled.
Check that all external controls are calling for heat.
Open the gas service isolation valve 'F', diagram 12.2.
Select the constant central heating with DHW function by
pressing "Mode", refer to the User Instructions for a more
detailed description.
NOTE: If DHW is selected the boiler will start the pre-heat
function.
The appliance will enter a self checking routine then the fan
should start and 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 the burner fails to ignite the display will show "F1".
Depress the 'reset' button on the fascia to clear the display
and repeat the ignition sequence.
Once the system has been purged of air, set the hot water
to the desired temperature by using the "DHW" and + (plus)
and - (minus) buttons.
Open a hot water tap, the diverter motor will move to hot
water supply and the display will read domestic hot water
temperature.
Check that hot water is available then close the hot water
tap.
Set the Central heating water temperature to the desired
temperature by using the "CH" and + (plus) and - (minus)
buttons.
The appliance will then continue to fire in central heating until
the user controls are satisfied.
NOTE: After ignition in central heating demand the boiler will
ramp slowly to full rate rather than going immediately to full
rate. This is an adaptive feature to cope with small system
requirements.
Supplied By www.heating spares.co Tel. 0161 620 6677
12 Commissioning
12.6 Gas Inlet Pressure
Check the supply pressure at the gas service isolation valve
test point, see diagram 12.2.
The nominal supply pressure should be 20mbar 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.
12.7 Gas Rate
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.
NOTE: The burner pressure cannot be
measured at the gas valve as it is altered by
the suction of the fan and modulated according
to demand.
Adjustment of the gas valve would require a combustion
analyser and should only be carried out by a competent
person, but in the unlikely event that the gas valve needs
adjusting, refer to section 13.7.
Flue Gases: If any doubt exists that the flue products are not
exhausting correctly, investigate by use of a flue gas analyser
(FGA).
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