24
221129A
1 1 C o m m i s s i o n i n g
11.5 Burner Pressure - Hot Water -
Honeywell
The burner pressure is factory preset and no adjustment
should be required.
Connect the electrical supply; the pump and fan will
operate for about 30 seconds, then the fan will reduce
speed and the pump stop.
Relight the pilot burner.
Fully open the largest hot water draw off tap whereby
the main burner will light, the flames gradually
increasing to the maximum.
Check the soundness of the boiler gas joints, with the
main burner on, using a leak detection fluid. Take care
not to splash any of the electrical components.
Fully open the hot water throttle, (clockwise), see
diagram 11.5. Check that the water flow rate is not less
than 9Litre/min. (2.0gall/min) to prevent any modulation
of the gas pressure. This is equivalent to 6.7 seconds to
fill a 1Litre container (3.8 seconds for 1pint).
To achieve this flow rate a water pressure of at least
0.8bar is required during commissioning, although
subsequently the appliance will work at a minimum
pressure of 0.5bar.
This flow rate should prevent any modulation of the
gas pressure.
Check the burner pressure is /-0.35mbar
(+/-0.14in wg). of 15.7mbar (6.3in wg), the hot water
burner pressure. If this is incorrect, the burner pressure
may be adjusted to the correct setting by turning the hot
water gas pressure adjuster (potentiometer), using an
insulated screwdriver, see diagram 11.6. Gain access to
the adjusters on the control board by removing the
control housing cover, see diagram 10.1. Turn the
adjuster slowly, always making adjustment by reducing
below the required pressure then increasing up to the
required setting, (turn clockwise to increase).
Close the hot water draw off.
If the maximum pressure cannot be obtained, check that
the gas supply of adequate size, refer to Section 1.8.
11.5 Burner Pressure - Hot Water - SIT
The burner pressure is factory preset and no adjustment
should be required.
Connect the electrical supply.
Relight the pilot.
Turn gas control knob “D” to “
“, main burner
position.
Fully open the largest hot water draw off tap whereby
the main burner will light, the flames gradually
increasing to the maximum.
Check the soundness of the boiler gas joints, with the
burner lit, using a suitable leak detection fluid. Take
care not to splash any of the electrical components.
Fully open the hot water throttle, (clockwise), see
diagram 11.5. Check that the water flow rate is not less
than 9Litre/min (2.0gall/min) to prevent any modulation
of the gas pressure. This is equivalent to 6.7 seconds to
fill a 1Litre container (3.8 seconds for 1pint).
To achieve this flow rate a water pressure of at least
0.8bar is required during commissioning, although
subsequently the appliance will work at a minimum
pressure of 0.5bar.
This flow rate should prevent any modulation of the gas
pressure.
Check that the burner pressure is 16.1mbar +/- 0.35mbar
(6.5in wg +/- 0.14wg) If this is incorrect, the burner
pressure may be adjusted by turning the larger brass
adjusting nut of the modulator, anti-clockwise to
decrease, after removing the cap, see diagram 11.2.
Fine adjustment may be achieved by turning the hot
water gas pressure adjuster (potentiometer), using an
insulated screwdriver, see diagram 11.6. Gain access to
the adjusters on the control board by removing the
control housing, see diagram 10.1.
Turn the adjuster slowly, always making adjustments by
reducing below the required pressure then increasing up
to the required setting, turn clockwise to increase.
Close the hot water draw off.
If the maximum pressure cannot be obtained, check that
the gas supply is of adequate size, refer to Section 1.7.
