PRINT AND SAVE THESE INSTRUCTIONS
WARNING! 120 volts may cause serious injury from electrical
shock. Disconnect power and shut off water supply before servicing.
APRILAIRE HUMIDIFIER MODELS 445A-445
- Cover Knob
- Top Cover
- Feed Nozzle
- Distribution Tray
- Metal Frame
WARNING! 120 volts may cause serious injury from electrical shock. Disconnect
power and shut off water supply before servicing.
- Note humidistat or control setting and turn dial to the "Off"
- Disconnect electrical power and turn off water supply.
- Remove two aluminum knobs (1), swing up and remove top cover (2) from
- 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.
- Tip forward and lift the complete plastic framed evaporative section out
of the humidifier.
- 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.
- 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.
- 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.
- See below for reservoir and pump cleaning.
IMPORTANT: Clean and refill reservoir, hose, pump and float every 30 days
during heating season.
- Pump Impellor Cap
- Cap Sides
- Cap Flow Control Opening
- Arm Mechanism
© RESEARCH PRODUCTS CORPORATION 1998
- TO CLEAN RESERVOIR
- Hold bottom of reservoir (IT IS FILLED WITH WATER) and loosen retainer
knob. Carefully lower reservoir, disengaging from metal frame.
- Empty water, remove partition and reservoir liner.
- Clean or replace reservoir liner. Reinstall partition in liner. To
replace reservoir, hook back of reservoir over lip of dark metal frame and
- TO CLEAN HOSE
- Disconnect hose from pump and pull hose up through hole.
- Flex hose to loosen scale and flush clean with a stream of water.
- Clean nozzle at the same time.
- TO CLEAN PUMP
- Remove pump impellor cap (1) by pushing down on projecting sides (2).
- Clean scale from inside of cover and impellor (3) with dull blade.
- Clean flow control (4) in pump outlet with 5/32" bit.
- Snap pump impellor cap (1) back in place.
- Pull water hose down through hole, connect to pump, and attach nozzle
into water distribution pan.
- TO CLEAN FLOAT
- Clean scale off float (5) and arm mechanism (6) with dull blade.
- Work arm mechanism (6) up and down to dislodge any scale buildup.
- TO OIL MOTOR
- Disconnect water line at valve inlet and swing line free. Disconnect the
- Remove the three screws from the brown motor cover and remove.
- Use two drops SAE 20 oil in the yellow hole on top and inside the yellow
mark on the side of the motor.
- TO REASSEMBLE
- Replace motor cover.
- To reinstall reservoir, hook back of reservoir over lip of dark brown
metal frame and tighten knob.
- Reconnect water at valve inlet.
- To reinstall top cover, hook back under lip of dark brown metal frame
and tighten two knobs.
- Reconnect humidistat or control leads and electrical power.
- Turn on water supply and fill reservoir in the fall.
- Check unit operation.
- 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.
- Set humidistat or Control to its original position.