Preferred
TM
Model PF845411/PF845412
I n s t a l l a t i o n , O p e r a t i o n , & M a i n t e n a n c e M a n u a l
10
Preferred Products
6.2 Control Board Faults & Reset
Faults are indicated by a red and green flashing LED located
on the base of the unit in the lower left corner. (See figure 9
above). There is a reset button on the control board that will
reset the unit in the event of a fault. Use the fault list below and
the troubleshooting chart to diagnose the fault and correct any
issues that may be present.
When the LED is glowing solid green, the unit is humidifying and
operating normally. The following list describes the faults that
may occur and will be displayed by the LED’s.
1. Rapid Red Blink = Terminals AP1 & AP2 for the air proving
switch did not close. The unit will not operate until airflow
is present.
2. Slow Red Blink = Once the solenoid valve is energized and
humidification has begun, the controls must see a change
in termperature or the unit will not be allowed to operate.
3. Alternating Red/Green Blink = One of the thermistors has
failed.
•
If T1 has failed the LED will blink Green/Red/Red with a
two second delay. The unit will not operate in this con-
dition unless DIP switch #5 is turned ON and the reset
button is pressed.
•
If T2 has failed the LED with blink Green/Green/Red with
a two second delay. The unit will not operate in this con-
dition unless the T1 thermistor is relocated to act as T2
and DIP switch #5 is turned ON. Using the override DIP
switch is only recommended as a temporary solution until
the failed thermistor can be replaced.
4. Solid Red LED = This functions to remind the homeowner
to replace the evaporator pad. The unit will continue to op-
erate and the LED may be cleared by pressing the reset
button on the control board.
6.3 Motor Replacement
1. Follow steps 1-7 in the pad replacement section in order to
separate the dome from the unit base.
2. Insert a flat-head screwdriver into the motor cover as shown
in Figure 15. Tilt the screwdriver up as shown in Figure 16.
This willl release the motor cover and allow you to slide it off
of the humidifier dome.
3. If you have a circuit board equipped unit (PF845412), un-
plug the motor cable from the circuit board. If you have
a unit not equipped with a circuit board, unplug the white
connector to free the motor leads from the relay board. The
motor/dome will now be free from the base of the humidifier.
4. With the motor cover removed, as described in step 2, dis-
connect the quick-connects from the black and white wires.
Also, remove the ground terminal from the motor by remov-
ing the ground screw.
5. Using an allen wrench, loosen the setscrew on the fan im-
peller to remove it from the motor shaft.
6. Using a nutdriver, remove the four nuts that secure the mo-
tor to the dome and remove the motor. Take care not to
misplace the nuts, washers, & grommets. These will be
used to mount the new motor.
7. Install the new motor to the dome using the nuts, washers,
& grommets that you removed from the old motor. Refer to
Figure 17 to see installation order.
8. With the new motor mounted to the dome, connect the
ground wire to the motor and reconnect the quick-connect
terminals on the black and white wires.
Figure 15
Figure 16
9. Replace the motor cover by sliding it onto the dome until it
bottoms out. Place the dome back on the base and secure
it with the screw removed previously. Refer to Figure 13.
10. Reconnect the motor cable that was disconnected as de-
scribed in step 3.
11. Close the access door on the dome and replace the screw.
Refer to Figure 12.