Glow-worm Xtrafast 96-120 - Manual (Page 22)

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14 Changing Gas Type
Bypass
The XTRAFAST boiler has a built-in bypass. This must be
adjusted according to the requirements of the system, refer to
the flow rate pressure curve (diagram 4). The boiler is supplied
with the built-in bypass open a half a turn. It is adjusted by
turning the bypass screw (a), see diagram 15.1. Turn the screw
clockwise to close the bypass. When using thermostatic
radiator valves (TRV’s) on all of the radiators, it is essential that
a separate, adjustable bypass of 15 mm minimum diameter is
fitted between the flow and return of the heating circuit, see
diagram 8.2. Any bypass must be fitted before system controls.
Diagram 15.1
9669
a
15 Settings
Should it become necessary to change the gas type, a
modification kit will be required.
This modification must only be carried out by a suitably qualified
engineer.
Conversion natural Gas (G20) to G30/G31 Part No. 86216.