A.O. Smith 30 - Manual (Page 47)

Instruction manual SGS 47
is
4 Conversion to a
different gas category
Caution
The conversion may only by carried out by an authorised installation
engineer.
If the appliance must operate on a family of gases (LP gas or natural gas) or
other gas category than that for which the appliance has been set at the
factory, the appliance will have be adapted using a special conversion kit.
Caution
You must check the supply pressure and burner pressure once the
conversion is complete.
Orifice assembly
Legend
1. connector
2. gas coupling
3. air supply hose
4. pressure switch hose
5. gas/air distribution plate
6. stamped figures