1611UDSBD-3GBEN, Pag. 29/36
19. Centrifugal
Fan
Remove dirt and grease from the motor and the blower wheel. Use care when
cleaning the wheel to prevent causing misalignment or imbalance.
Follow these instructions for replacement of the direct driven centrifugal fan.
1. If the heater is installed, turn off the gas and disconnect the electric power.
2. Open the connection box on the blower and disconnect the fan motor wires.
3. Remove the blower.
4. Position the new blower on the heater.
5. Reconnect the fan motor wires according to the wiring diagram and close the
connection box on the blower.
6. Restore power to the heater and turn on the gas. Light, following the instructions
on the lighting instruction plate. Check for proper operation.
18. Blower
motor
The blower motor is equipped with thermal overload protection of the automatic
reset type. Should the motor fail to run, it may be because of improper voltage
characteristics. Make certain that the correct voltage is available at the motor.
Figure 17 - Control relay
Flame sensor
- Refer to fi gure 11a and locate the fl ame sensor. Disconnect the
wire, remove the screw and the fl ame sensor. Clean with an emery cloth..
Control relay
- See fi gure 17. The electronic burner relay monitors the operation
of the heater including ignition. Do not open the control relay. Each heating season
check the lead wires for insulation deterioration and good connections.
Proper operation of the direct spark ignition system requires a minimum fl ame
signal of 1.0 microamps (DC) as measured by a microammeter.
For further information and check out procedure on the direct spark ignition system,
refer to section 12 and the Troubleshooting Flow Chart in section 25.
Figure 16a
Ignitor showing required
spark gap measurement
Fuse
Flame sensor
Caution :
Due to high
voltage on the spark wire
and electrode, do
not
touch
when energized.
Figure 16b
