Maintenance Instructions; Models 558 & 550; Models 568 & 560 - Aprilaire 112 Owner's Manual

MAINTENANCE INSTRUCTIONS

APRILAIRE HUMIDIFIER MODELS 558-550-568-560
CAUTION! Sudden operation may cause personal injury or property damage. Turn
humidistat or control to "off" or lowest setting before servicing.
1
1. Note humidistat or control setting and turn dial to the "OFF" position.
2. Turn off water supply.
3. At the side of the unit opposite the airflow duct pull front cover (1) off hold-
ing with both hands and set aside.
4. Carefully pull the plastic feed tube (2) out of the nozzle (3) at the top of the
Water Panel evaporative assembly (4). Pull this assembly out by grasping at
top and tipping out.
5. Remove the black plastic distribution tray (5) from the evaporative assembly
by unsnapping the white plastic holding strips from the tabs at the end of
the tray. Lightly scrape out any calcium deposits and clean the "V" notches
(6), but do not scrape off the granular coating from the bottom. This
textured surface helps ensure even water flow for maximum performance.
See page 2 if removed.
6. Slide the Water Panel evaporator (7) out from the white plastic Scale
Control Insert (8). Clean the insert frame by twisting and flexing it to loosen
the calcium deposits, or use a putty knife. Inspect the Water Panel evapo-
rator (Stock No. 10 for Model 550 and Stock No. 35 for Model 560) and
substitute a new one if necessary. Slide the pad back into the insert frame
with the black colored spot up and snap the black distributor tray back into
place.
7. Re-install the Water Panel evaporative assembly into the unit by fitting its
drain tube into the round receptacle at the base of the unit. Push the
assembly in at the top against the beveled tabs that will hold it in place.
Push the end of the feed tube back firmly into the nozzle and replace the
front cover.
8. Remove the drain hose (9) from the bottom of the unit and bend and flex it
to loosen the internal calcium deposits. Then flush it with water under pres-
sure and slip it back onto the black drain fitting.
9. Turn on water supply.
10. 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%.
Automatic Humidifier Control: Check system operation by setting the
knob to "Test." With furnace blower operating and furnace calling for
heat, humidifier will operate for one minute.
11. Set humidistat or Control to its original position.
for
5 6
3
1
9
2
- 9 -
4
8
1. Front Cover
2. Feed Tube
3. Nozzle
4. Water Panel Evapo-
rative Assembly
5. Distribution Tray
6. "V" Notches
7. Water Panel
8. Scale Control Insert
9. Drain Hose