Aprilaire 440 Technical specifications

Maintenance Instructions:
Aprilaire Models 440, 445 & 445A
1. Note Humidifier Control setting and turn dial to the “OFF” position.
2. Disconnect electrical power and turn off water supply.
3. Remove two aluminum knobs (1). Swing top cover up and remove from
humidifier.
4. Place finger under white feed nozzle (3) at top of water distribution tray (4).
Lift up to pop feed nozzle loose from hole and notch in distribution tray.
5. Pull out the water panel evaporator assembly by grasping at the top and
tipping out.
6. Unsnap the distribution tray (4) from the scale control insert. Follow the
instructions below depending upon the type of distribution tray in your
humidifier:
a. For trays with a synthetic fabric liner: Lightly scrape out or brush off
any mineral deposits being careful not to stretch or loosen the
synthetic fabric liner. Soaking the tray in vinegar or a lime-removing
agent is helpful when trying to remove stubborn mineral deposits.
b. For trays with granular coating: Do not scrape off the granular
coating. Lightly scrape out any mineral deposits and clean the “V”
notches (5). This textured surface helps ensure even water flow for
maximum performance. If the granular coating has been removed,
place several drops of liquid dishwashing soap on the distribution tray.
This will only need to be done once if there is no granular coating.
7. Slide the Water Panel evaporator out from the scale control insert. Clean the
scale control insert of mineral deposits. Slide the new Water Panel evaporator
into the scale control insert with the colored spot up and snap the
distribution tray (4) back into place.
8. Inspect feed tube by gently flexing it and looking for cracks or signs of wear.
Replace tube if it is cracked, brittle, or has been damaged.
9. Reinstall the Water Panel evaporator assembly into the humidifier (with the
whole in the distribution tray toward you) by fitting its drain directly over the
round receptacle at the base of the humidifier. Push the assembly in at the
top to a vertical position. Pop feed nozzle (3) on the end of the feed tube into
hole and notch in distribution tray (4).

10. Replace top cover (2) hooking back of cover under lip of metal frame (5) and
tighten two knobs (1).
11. Remove the drain line (if applicable) from the bottom of the humidifier. Flex it
to loosen any mineral deposits or blockage. Then flush it with water under
pressure. If it does not clear, replace it. Slip drain line back onto the drain
fitting. Make sure the drain line has a constant downward slope and is not
flattened or blocked.
12. Reconnect electrical power and turn on the water supply.
13. Check system operation:
a. Manual Humidistat: With the furnace blower operating and the
furnace calling for heat, turn up humidistat and check system
operation.
b. Humidifier Control: (Automatic or Manual mode) Check system
operation and reset Change Water Panel indicator by turning the knob
to “Test/Reset.” With furnace blower operating and furnace calling for
heat, humidifier will operate for one minute. DO NOT LEAVE IN TES T
MODE AS HUMIDIFIER WILL NOT OPERATE.
14. Set humidifier Control to its original position.