Indirect Gas-Fired Heat Modules
16
Gas Valves
Overview of typical Selectra Valve. Used in 2:1
Electronic Modulation
Low Fire
Adjusting Screw
Control Wire
Terminals
Vent
Overview of typical Single Stage Valve. Used in 4:1 and
2:1 Electronic Modulation and in Single Stage Furnaces
Gas Control Knob
(ON / OFF)
High Fire
Adjusting Screw
Overview of typical Two Stage Valve. Used in eight
stage and two stage furnaces.
Overview of typical Modulating Valve. Used in 4:1
Electronic Modulation
Low Fire and High Fire
adjustments are made
on printed circuit board
behind removable cover
Low Fire
Adjusting Screw
High Fire
Adjusting Screw
Terminal Block
Gas Control Knob
(ON / OFF)
Close-up of Terminal Block
High fire terminal is the bottom of
three terminals.
LO
C
HI
®