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
8
Preferred Products
is too large for the load, you may change the DIP switch
position to ON. It is not necessary in most cases.
•
DIP #3 = Temperature Check - If you are installing this
humidifier on a system that will have duct temperatures
regularly below 100°F, set this DIP switch to the OFF po-
sition. Typical furnace bonnet temperature is nominally
120°F.
•
DIP #4 = Furnace Runs Fan/Humidifier Runs Fan - In
most systems the HVAC system operates the main blow-
er. The PF845412 has a 24VAC output that may be used
to start the main blower if you would like to be able to get
some humidfication while the furnace is off.
•
DIP #5 = Temperature Override - This DIP switch is fac-
tory set to OFF. In the event of a T1 thermistor failure,
this switch may be set to ON. This will allow the humidi-
fier to operate temporarily with a single thermistor until a
replacement is aquired.
5.1 Preliminary Checkout and Start-up Sequence
1. Check that unit drain plumbing is properly connected and
drained.
2. Ensure that the supply plumbing is installed properly.
3. Open cold water supply and insure water is reaching the
unit. Incoming water line should be filtered.
4. Ensure that the unit’s line cord is plugged into an appro-
priate power source.
5. With the unit powered and the humidistat has a “call for
humidity”, the indicator LED (if equipped) will illuminate
Green and the unit will begin operation.
6. If at any point the indicator LED illuminates red or blinks
red/green alternating, a fault has been detected; service
will be required and the fault must be reset. Refer to the
Maintenance & Troubleshooting section.
7. Refer to the humidistat manual for “call for humidity” per-
centage settings.
5.2 Starting/Stopping the unit
In order to start and stop the unit you must only raise or lower
the humidistat setting to a point at which the contacts are closed
or open. When the humidistat contacts are closed, the unit will
start. When the humidistat contacts are open, the unit will stop.
Unplugging the line cord may not remove all sources of power
to the unit.
6. Maintenance & Troubleshooting
!
DANGER - RISK OF ELECTRIC SHOCK
Before cleaning, servicing, or parts replacement, the unit must
be disconnected from all sources of electricity.
6.1 Pad Replacement
It will become necessary to replace the pad inside your Pre-
ferred
TM
PF845411/PF845412 humidifier as time goes on. A
solid red LED Service indicator light may light up. This will tell
you that it is time to service your humidifier. Please refer the
following procedure.
1. Adjust Humidistat to the lowest setting to ensure that
•
DIP Switch #4: Off
•
Air Proving Switch: Recommended but not required.
If no air proving switch is used, install a jumper across
the AP1/AP2 terminals
•
Go Terminal: No Connection
•
W/G Terminal: Connected to System “W”
Multi Stage/Modulating Furnace: Humidifier operates upon
call-for-humidity only during a call-for-heat.
•
DIP Switch #3: Off
•
DIP Switch #4: Off
•
Air Proving Switch: Required
•
Go Terminal: No Connection
•
W/G Terminal: No Connection
Single or Multi Stage Furnace: Humidifier operates upon a
call-for-humidity and will start the HVAC blower.
•
DIP Switch #3: Off
•
DIP Switch #4: On
•
Air Proving Switch: Recommended but not required.
If no air proving switch is used, install a jumper across
the AP1/AP2 terminals
•
Go Terminal: Connected to System “G”
•
W/G Terminal: No Connection
Although the capacity of the humidifier may be reduced by
more than 40%, the PF845412 may be installed on a heat
pump system and configured to operate only when there is a
call-for-heat OR the humidifier may be configured to start the
HVAC blower whenever there is a call-for-humidity.
Heat Pump System: Humidifier operates upon call-for-
humidity only during a call-for-heat.
•
DIP Switch #3: Off
•
DIP Switch #4: Off
•
Air Proving Switch: Required
•
Go Terminal: No Connection
•
W/G Terminal: No Connection
Heat Pump System: Humidifier operates upon a call-for-
humidity and will start the HVAC blower.
•
DIP Switch #3: Off
•
DIP Switch #4: On
•
Air Proving Switch: Recommended but not required.
If no air proving switch is used, install a jumper across
the AP1/AP2 terminals
•
Go Terminal: Connected to System “G”
•
W/G Terminal: No Connection
5. Operation
Once the PF845411/PF845412 is installed and ready to be start-
ed, the humidistat and DIP switches on the control board within
the humidifier unit must be confirgured. The PF845411 without
the water saving controls does not have any DIP switches to
configure. You may skip to the Preliminary Checkout and Start-
up Sequence.
DIP Switches/Settings:
•
DIP #1 = Bypass or Motorized (Factory Set)
•
DIP #2 = High Capacity/Low Capacity - This is factory
set to High Capacity. If you determine that the humidfiier