VI. PERIODIC PREVENTATIVE MAINTENANCE
NOTE: Periodic inspection and preventive maintenance of your total
heating system is important for efficient and safe operation. Your heating
dealer should perform humidifier service at the same time.
All models are equipped with an in-line water strainer and orifice as
shown below. These parts should be inspected and cleaned periodically to
assure continued proper humidifier performance.
*M
A
Y
B
E
“A
”
O
R
“T
”
M
O
D
E
LS
*H
U
M
D
20
0A
B
M
00
B
,
*H
U
M
D
30
0A
B
A
00
B
MAINTENANCE INSTRUCTIONS for HUMIDIFIER
MODELS *HUMD200ABM00B, *HUMD300ABA00B
- 8 -
- 9 -
WARNING
Disconnect Electrical Power and Shut Off Water
Supply Before Servicing. Failure to follow this warning may cause
property damage, personal injury or death.
CAUTION
Turn Humidifier Control to “OFF” or lowest
setting before servicing. Sudden operation may cause personal injury
or property damage.
CAUTION
Turn Humidifier Control to “OFF” or lowest setting before servicing.
Sudden operation may cause personal injury or property damage.
1. Disconnect electrical power to the furnace and
shut off water supply.
2. Disconnect the water line at the inlet
compression nut.
3. Remove the in-line strainer from inside the inlet
side of the valve by using a small nail or wire.
4. Flush the in-line strainer clean or replace with a
new strainer, Service Part No. SRA00859.
5. Reconnect the inlet water line.
Double Wrench
to Prevent Leaking.
6. Disconnect the water feed tube at the outlet
compression nut.
7. Inspect the water feed tube (plastic only) by
gently flexing it and looking for cracks or signs of
wear. Replace tube if it is cracked, brittle, or has
been damaged.
8. Remove the orifice from the copper or plastic
water feed tube and make sure this small
opening is unplugged.
9. Replace the orifice and reconnect the water feed tube.
Double Wrench to
Prevent Leaking.
10. Remove the drain line from the bottom of the humidifier. If applicable, flex it to
loosen any mineral deposits or blockages. Flush the drain line with water under
pressure to clear it of any debris, and slip it back onto the drain fitting. If drain
line does not clean properly, replace it. Inspect the drain line to make sure it
has a constant downward slope and is not flattened or blocked.
11. Turn on water supply and reconnect electrical power to the furnace.
WATER LINE INSPECTION AND SERVICE INSTRUCTIONS
INLET
COMPRESSION
NUT
INLET
SOLENOID
VALVE
ORIFICE
OUTLET
COMPRESSION
NUT
IN-LINE
STRAINER
WATER
FEED TUBE
90-1053
9
6
3
7
8
5
2
1
4
1. Note Humidifier Control setting and turn dial to the “OFF” position.
2. Turn off water supply. Turn the integral bypass damper (3) to the SUMMER position.
3. Press the tabs in the latches on the top and bottom of front cover (1) and pull cover off base
with both hands. Set aside.
4. Carefully pull the plastic feed tube (2) out of the distribution tray (5) at the top of the
evaporative assembly (4). Pull this assembly out by grasping at top and tipping out.
5. Unsnap the distribution tray (5) from the scale control insert (8). 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.
6. Slide the Humidifier Pad (7) out from the scale control insert (8). Clean the scale control
insert of mineral deposits. Replace the Humidifier Pad annually with a BAYPAD01A1010A
Humidifier Pad for Model *HUMD200ABM00B and BAYPAD02A1310A Humidifier Pad for
Model *HUMD300ABA00B. Slide the Humidifier Pad back into the scale control insert with
the colored spot up and snap the distribution tray (5) back into place.
7. Inspect the plastic feed tube (2) by gently flexing it and looking for cracks or signs of wear.
Replace tube if it is cracked, brittle, or has been damaged.
8. Reinstall the evaporative assembly (4) into the humidifier by fitting its drain into the round
receptacle at the base of the humidifier. Push the assembly in at the top until it snaps into
place. Push the end of the feed tube (2) back firmly into the distribution tray and replace the
front cover (1).
9. Remove the drain line (9) from the bottom of the humidifier. If applicable, flex it to loosen any
mineral deposits or blockage. Then flush it with water under pressure. If it does not properly
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.
10. Turn on the water supply. Return integral bypass damper (3) to appropriate position.
11. Check system operation:
Manual Humidifier Control (*HUMD200ABM00B):
With the furnace blower operating and
the furnace calling for heat, turn up Control and check system operation.
Automatic Humidifier Control (*HUMD300ABA00B):
(Automatic or Manual mode) Check
system operation and reset Change Humidifier Pad indicator by setting the knob to
“Test/Reset”. With furnace blower operating and furnace calling for heat, humidifier will
operate for one minute. DO NOT LEAVE IN TEST MODE AS HUMIDIFIER WILL NOT OPERATE.
12. Set Humidifier Control to its original position.
1. Front Cover
2. Feed Tube
3. Integral Bypass
Damper
4. Evaporative
Assembly
5. Distribution Tray
6. “V” Notches
7. Humidifier Pad
8. Scale Control Insert
9. Drain Line
90-1169
