Aprilaire 448 User manual

MAINTENANCE INSTRUCTIONS
for
APRILAIRE HUMIDIFIER MODELS 448-445A-445
WARNING! 120 volts may cause serious injury from electrical shock. Disconnect power and shut off water supply
before servicing.
Key
Cover Knob1.
Top Cover2.
Feed Nozzle3.
Distribution Tray4.
Metal Frame5.
Maintenance Instructions
Note humidistat or control setting and turn dial to the "Off" position.1.
Disconnect electrical power and turn off water supply.2.
Remove two aluminum knobs (1), swing up and remove top cover (2) from humidifier.3.
Place finger under white plastic water outlet (3) at top of black water distribution pan (4). Lift up to pop outlet loose
from hole and notch in black distribution pan.
4.
Tip forward and lift the complete plastic framed evaporative section out of the humidifier.5.
To remove black plastic water distribution pan from evaporative section, push down on pan and out on white plastic
frame (Scale Control Insert). Clean "V" openings in water distribution panel but do not scrape coating off bottom
surface.
6.
Remove Water Panel evaporator and Scale Control Insert. Remove Water Panel evaporator from Insert and clean
insert by flexing or using putty knife. Inspect Water Panel evaporator and replace with a new Water Panel evaporator,
if necessary, with colored spot up.
7.
Re-install black water distribution pan. Reinstall evaporative section in the humidifier, with notch and hole in
distribution pan toward you. Pop hose fitting on end of feed tube into distribution pan.
8.
See below for reservoir and pump cleaning.9.

MAINTENANCE INSTRUCTIONS
FOR MODELS 445A-445
RESERVOIR PUMP SECTIONS
WARNING! 120 volts may cause serious injury from electrical shock. Disconnect power and shut off water supply
before servicing.
IMPORTANT: Clean and refill reservoir, hose, pump and float every 30 days during heating season.
Key
Pump Impellor Cap1.
Cap Sides2.
Impellor3.
Cap Flow Control Opening4.
Float5.
Arm Mechanism6.
TO CLEAN RESERVOIR
Hold bottom of reservoir (IT IS FILLED WITH WATER) and loosen retainer knob. Carefully lower reservoir,
disengaging from metal frame.
1.
Empty water, remove partition and reservoir liner.2.
Clean or replace reservoir liner. Reinstall partition in liner. To replace reservoir, hook back of reservoir over
lip of dark metal frame and tighten knob.
3.
A.
TO CLEAN HOSE
Disconnect hose from pump and pull hose up through hole.1.
Flex hose to loosen scale and flush clean with a stream of water.2.
Clean nozzle at the same time.3.
B.
TO CLEAN PUMP
Remove pump impellor cap (1) by pushing down on projecting sides (2).1.
Clean scale from inside of cover and impellor (3) with dull blade.2.
Clean flow control (4) in pump outlet with 5/32" bit.3.
Snap pump impellor cap (1) back in place.4.
Pull water hose down through hole, connect to pump, and attach nozzle into water distribution pan.5.
C.
TO CLEAN FLOAT
Clean scale off float (5) and arm mechanism (6) with dull blade.1.
D.

Work arm mechanism (6) up and down to dislodge any scale buildup.2.
TO OIL MOTOR
Disconnect water line at valve inlet and swing line free. Disconnect the humidistat leads.1.
Remove the three screws from the brown motor cover and remove.2.
Use two drops SAE 20 oil in the yellow hole on top and inside the yellow mark on the side of the motor.3.
E.
TO REASSEMBLE
Replace motor cover.1.
To reinstall reservoir, hook back of reservoir over lip of dark brown metal frame and tighten knob.2.
Reconnect water at valve inlet.3.
To reinstall top cover, hook back under lip of dark brown metal frame and tighten two knobs.4.
Reconnect humidistat or control leads and electrical power.5.
Turn on water supply and fill reservoir in the fall.6.
Check unit operation.7.
Check system operation:
Manual Humidistat: Turn up humidistat to highest setting and make sure the furnace blower is
operating. Humidifier will operate if RH is less than 50%.
Auto Trac Control System: Check system operation by setting the knob to "Test". With furnace blower
operating and furnace calling for heat, humidifier will operate for one minute.
8.
Set humidistat or Control to its original position.9.
F.
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