L.B. White Guardian with Smart Sense / Direct Connect - Spark Ignition (250K) - Manual (Page 17)

16
SIGNAL CONDITIONER
If replacing the signal conditioner:
■
Handle the replacment conditioner at its edges.
■
Don’t touch the signal conditioner components,
otherwise damage may occur.
■
Snug in the conditioner’s mounting screws to
prevent board damage. Do not overtighten.
FIG. 14
1. The igniter and sensor assembly is located within a
metal enclosure mounted to the heat chamber above
the burner.
2. The igniter/sensor is serviced by removing the screw
that secures the assembly to the heat chamber.and
disconnect the its leads from the ignition control. Lift
the assembly from its mounting slots. See Fig. 13.
3. Reconnect the heater to its electrical supply. Open
the fuel supply valves to the heater.
■
The igniter/sensor assembly may require cleaning due
to accumulations of dust and dirt over a period of time,
thereby affecting its ability to ignite fuel gas and sense
burner flame. Cleaning will require igniter/sensor
removal.
--
If spark appears to be weak, briskly rub the igniter
electrode with emery cloth or steel wool to remove
any buildup. Recycle the heater.
--- If the spark appears strong but the heater cycles off,
briskly rub the sensor rod with emery cloth or steel
wool to remove any build-up. Restart the heater.
■
Ensure the igniter gap is 1/8 -3/16 in. and the igniter
tip is positioned over the burner port according to the
illustration below. See Fig. 13.
IGNITER AND FLAME SENSOR
AIR PROVING SWITCH WITH PADDLE
The air proving switch must work properly to allow an
ignition cycle. If the air proving switch contacts do not close
on a call for heat after the fan motor starts,ignition will not
occur.
1. Open the case access panel on the control box end of
the heater.
2. Remove the two (2) sheet metal screws holding the
switch with bracket to blower housing and turn the
switch assembly 90°so the paddle on the switch arm
can be pulled through the oblong hole on side of fan
housing.
NUTS
SWITCH W/PADDLE
PADDLE
OBLONG HOLE
LEADS
HOUSING SIDE
PANEL
FIG. 12
SENSOR IGNITER
4 MM
HEAT CHAMBER FA
BURNER
IGNITER / SENSOR
ENCLOSURE
SOR WITH ENCLOSURE
IFT ASSEMBLY
TING SLOTS
GNITER LOOSEN SCREW.
CLOSURE UP OR DOWN
W PROPER POSITIONING
NITER TO BURNER.
IGNITER ENCLOSURE
IGNITER
HEAT CHAMBER
3/16 in.
SENSOR
BURNER
LOOSEN SCREW AND SLIDE
IGNITER ENCLOSURE UP OR
DOWN TO MAINTAIN PROPER
GAP. FOR SERVICING,
REMOVE THE SCREW AND
LIFT THE ENCLOSURE FROM
THE MOUNTING SLOTS IN
HEAT CHAMBER.
FIG. 13