Gas Rate - Modulation - Sit; Gas Rate Modulation - Honeywell - Glow-worm swift flow 100 Installation Instructions Manual

11.6 Gas Rate - Modulation - SIT

The minimum gas rate is factory preset and no
adjustment should be required.
ALWAYS CHECK THE HOT WATER BURNER
PRESSURE FIRST - REFER TO SECTION 11.5.
To check the minimum gas rate, first make sure that the
boiler is isolated from the electrical supply at the
external isolator. Disconnect one of the electrical
connectors, grey, from the modulator, see diagram 11.2.
INSULATE THE CONNECTOR TO MAKE SURE
THAT IT DOES NOT CONTACT ANY METALLIC
PARTS.
Switch on the electrical supply.
Fully open a hot water draw off tap and the main burner
will light at the minimum gas rate.
Check that the burner pressure is 1.7mbar +/- 0.2mbar
(0.7in wg +/- 0.1 in wg). If this is incorrect, it may be
adjusted by turning the centre, white adjuster screw of
the modulator, anti-clockwise to decrease, whilst at the
same time stopping the larger brass nut from turning, see
diagram 11.2.
Isolate the boiler from the electrical supply then
reconnect the modulator cable and refit the cap.
1 1 C o m m i s s i o n i n g

11.6 Gas Rate Modulation - Honeywell

The minimum gas rate is factory preset and no
adjustment should be required.
ALWAYS CHECK HOT WATER BURNER
PRESSURE FIRST - REFER TO SECTION 11.5.
To check the minimum gas rate, first make sure that the
boiler is isolated from the electrical supply at the
external isolator. Disconnect one of the electrical
connectors (grey), from the modulator, see diagram 11.3.
Insulate the connector to make sure that it does not
contact any metallic part of the boiler.
Switch on the electrical supply.
Fully open a hot water draw off tap and the main burner
will light at minimum gas rate.
Check that the burner pressure is 2.4mbar +/-0.2mbar
(1in wg +/-0.1in wg). If this is incorrect, it may be
adjusted by removing the cap and turn the larger
adjusting nut of the modulator, (anticlockwise to
decrease pressure).
If the above adjustment was necessary, it will be
essential to check that the maximum pressure can still be
obtained. Push the spindle gently in to the stop and hold
it in. The maximum pressure should not be less than
16mbar (6.4in wg). If this pressure cannot be achieved,
obtain it by turning the small adjusting nut (clockwise to
increase the pressure). Always adjust the minimum
pressure first.
If the maximum pressure is unobtainable, check that the
gas supply is of adequate size, refer to Section 1.8. Put
right as necessary.
Isolate the boiler from the electrical supply then
reconnect the modulator cable and refit the cap.
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220650B