Checking The Gas Rate; Domestic Hot Water; Domestic Hot Water Pre-Heat - Worcester 29CDi GC 47-406-34 Installation, Commissioning And Servicing Instructions

B If left in the Performance test mode the control will return to normal
operation after 15 minutes.
B Close the gas isolation valve and remove the manometer.
B Re-seal the screw in the gas inlet pressure test point.
B Open the gas isolation valve and check for gas tightness.
GAS PRESSURE WITHIN THE SYSTEM
Refer to the figure below for natural gas pressures.
The pressure at the boiler must not be less than the pressure read at the
meter minus 1 mbar.
The pressure drop from the meter to the gas valve must not be more than
2.5 mbar for natural gas.
If the pressure drops are greater than shown in figure 41, then this
would indicate a problem with the pipe work or connections within the
system.
Meter
Natural Gas
19 - 23 mbar
Boiler inlet
1 mbar
drop
18 - 22 mbar
Fig. 41 Natural gas pressures
Refer to the figure below for L.P.G gas pressures.
The pressure at the boiler must not be less than the pressure read at the
meter minus 2.5 mbar.
The pressure drop from the meter to the gas valve must not be more than
4 mbar for LPG.
If the pressure drops are greater than shown in figure 42, then this
would indicate a problem with the pipe work or connections within the
system.
Regulator
L.P.G.
32 - 45 mbar
Boiler inlet
2.5 mbar
drop
29.5 - 42.5 mbar
Fig. 42 L.P.G. pressures
NOTICE:
Do not continue commissioning until the correct gas
pressure is achieved.
6 720 803 599 (2012/06)

5.5.2 CHECKING THE GAS RATE

B The gas rate should be measured at the gas meter after 10 minutes
B Where a gas meter is not available (e.g. L.P.G.) the CO/CO
B If pressure and gas rate are satisfactory press the Performance test
Gas Control
B Close the gas isolation valve.
valve
B Remove the manometer.
B Re-seal the screw in the gas inlet pressure test point.
B Open the gas isolation valve.
B Ensure that there are no gas leaks.
B Replace the outer case.

5.5.3 DOMESTIC HOT WATER:

16.5 - 20.5 mbar
Controlling the hot water temperature
B The hot water temperature can be set to between approximately 40°C
1.5 mbar
drop

5.5.4 DOMESTIC HOT WATER PRE-HEAT:

Pre-heat reduces the time taken to produce hot water at the tap and is
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controlled by the ECO button (F).
B Press the ECO button to select either:
When the ECO button is not illuminated the boiler will be in pre-heat
mode (which will reduce the time taken to produce hot water at the tap).
OR
When the ECO button is illuminated the boiler will be in Economy mode
with pre-heat no longer active.
Gas Control
valve
28 - 41 mbar
1.5 mbar
drop
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operation at maximum.
See technical data section at the front of this manual.
– Press the Performance test button (J) for more than ten seconds
and set Central Heating temperature to maximum.
– The Performance test button (J) will illuminate continually and the
display (C) will alternate between
temperature.
checked to the units shown in the setting of the air/gas ratio, refer to
section 6.2.
button again and the boiler will return to normal operation.
– If left in the Performance test mode the control will return to normal
operation after 15 minutes.
and 60°C using the temperature control (H).
COMMISSIONING
and the central heating flow
must be
2
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