Glow-worm swift flow 75e Installation Instructions Manual page 24

11.5 Gas Rate Modulation
The minimum gas rate is factory preset and no
adjustment should be required.
ALWAYS CHECK HOT WATER BURNER
PRESSURE FIRST - REFER TO SECTION 11.4.
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 the minimum gas rate.
Check that the burner pressure is 2.4mbar +/-0.2mbar,
(1.0in wg +/-0.1in wg) for the 75e and 2.2mbar
+/- 0.2mbar ( 0.9inwg +/- 0.1 in wg) for the 80e. If this
is incorrect, it may be adjusted by removing the cap and
turning the larger adjusting nut of the modulator, (anti-
clockwise to decrease the 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
16.1mbar, (6.5in wg) for the 75e or 16.3mbar, (6.5in
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 unattainable, check that the
gas supply is of adequate size, refer to Section 1.7 "Gas
Supply". Put right as necessary.
Isolate the boiler from the electrical supply then
reconnect the modulator cable and refit the cap.
221138C
1 1 C o m m i s s i o n i n g
24
DOMESTIC
HOT
WATER
THROTTLE
Diagram 11.5