Models 220 & 224 - Aprilaire 112 Owner's Manual

MAINTENANCE INSTRUCTIONS
APRILAIRE HUMIDIFIER MODELS 220-224
CAUTION! Sudden operation may cause personal injury or property damage.
Turn humidistat to "off" or lowest setting before servicing.
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1
2
3
1. Turn off water supply and turn down humidistat.
2. Remove three "Z" clips (1) that hold top half of unit to furnace plenum.
3. Slide off four closure clips (2 & 3) that hold two halves of unit together.
4. Loosen compression fitting (4) on copper feed tube (6) and remove.
5. Remove top screw holding sheet metal elbow to humidifier.
6. Remove top half of unit (lift straight up).
7. Remove the water distribution pan cover (5) and clean "V" openings in
water distribution section but do not scrape off granular coating
from bottom. This helps to insure proper, even water flow for maximum
performance. See page 2 if removed.
8. 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 (Stock No. 10 for Model 220 and Stock No. 12
for Model 224), with colored spot up.
9. Remove the drain hose from the bottom of the unit and bend and flex it
to loosen the internal calcium deposits. Then flush it with water under
pressure and slip it back onto the black drain fitting.
10. IMPORTANT: When installing the Scale Control Insert and Water Panel
evaporator in the humidifier, the Insert spout must discharge directly
into unit drain.
11. Reassemble unit, position feed tube in compression fitting, tighten
compression nuts and secure copper feed tube to upper housing with
feed tube clamp. Attach to furnace plenum.
12. Turn on water supply, turn up humidistat and check unit operation.
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5
6
2
4
3
1. "Z" Clip
2. Closure Clip
3. Closure Clip
4. Compression Fitting
5. Distribution Pan Cover
6. Feed Tube