20
Guardian 2.0 LP or Natural Gas Heater
Burner Orifice and Gas
Control Valve
1. Remove the burner retaining bolt from underside
of base. See Fig. 24.
2. Pivot the valve/manifold assembly as necessary
so the orifice on the manifold clears the burner
casting venturi port. See Fig. 25.
FIG. 24
UNDERSIDE OF BASE
LOCK
FLAT
WASHER
WASHER
BOLT
FIG. 25
GAS CONTROL VALVE
Owner's Manual • Guardian 2.0
Ignition Control
The control sends and receives voltages to operate
or verify operation of components. Refer to the fol-
lowing and Fig. 26 to understand the ignition control's
terminal designators if doing voltage checks on the
control.
MOTOR: 120 VAC to motor
L1: 120 VAC power supply
HSI (AW models): 120 VAC to hot surface igniter.
HSI (AW models): Neutral return of igniter
NEU (AW models): Neutral
24VAC: 24 VAC input from transformer
PSI: 24 VAC to air pressure switch
FS (AW models): Micro amperage to flame sensor
for proving burner flame.
GV: 24 VAC to high limit switch and then to gas
control valve.
PSO: 24 VAC from air pressure switch.
GND: Transformer ground.
GND: Burner ground.
LED CONNECTOR: Connection for diagnostic light
Also refer to "Operation Sequence" within this manual
as needed to understand operation of the ignition
control during a call for heat.
FIG. 26
Ignition Control (HSI shown)
L1