GeneralAire 900 SERIES, ELITE 900 Instructions For Use And Installation

Fresh Indoor Air Quality

READ AND SAVE THESE INSTRUCTIONS

R

900 SERIES

INSTALLER: PLEASE FILL OUT AND MAIL WARRANTY CARD AFTER INSTALLATION IS
COMPLETE. LEAVE INSTALLATION INSTRUCTIONS WITH HOME OWNER

PRECAUTION: The installer should be an experienced service technician. Disconnect electrical power before
beginning installation. Do not install where temperatures fall below 32 degrees F or where plenum temperatures
exceed 150 degrees F. When wiring into a multi-speed blower circuit see Step 9D.

INSTALLATION: The humidifier may be mounted with the 6" outlet to
the right or left by inverting the cabinet and reversing the positions of
the distributor trough and drain pan. The humidifier may be mounted
on the warm or return air plenum with equal efficiency.
See Typical Installations.

ADDITIONAL MATERIALS THAT MAY BE NECESSARY:

1. 1/4" diameter plastic supply tubing or 1/4" copper
supply tubing for hot water applications

2. 6" diameter galvanized by-pass pipe

3. electrical wire and wire nuts

4. current sensing relay (G.F. Model #GA50 suggested)

5. #8 self piercing sheet metal screws

1

WARM AIR

3

UP FLOW

RETURN AIR

DRAIN

GENERALAire AC SERIES

HIGH EFFICIENCY AIR CLEANER

R

FLOW-THROUGH

BYPASS HUMIDIFIER

FOR INSTALLATION ON A VERTICAL

PLENUM SURFACE OF ANY

FORCED AIR FURNACE

RETURN AIR

DRAIN

WARM AIR

DOWN FLOW

WARM AIR

12”

8-7/8”

The GeneralAire model 900 may be installed on either the supply or
return plenum of a forced air handling system. Select a location for the
humidifier that allows for service and maintenance. Cut out a rectangle
8-7/8” wide by 12“ tall. Extend horizontal centerline of cut out to the
adjacent plenum. Cut a 6” hole 10” to 15” from side of humidifier, on
cabinet centerline, using connecting collar as guide. The bypass is
reversible and can be mounted on the right or left side of the
humidifier.

2

1

2

Humidifier is self retaining. Slide top side in first, then slide chassis
down. Level chassis and install center screws. If by-pass pipe installs to
opposite side of chassis, bend clip on chassis, remove side discharge,
and reinstall discharge to opposite side of chassis. Install remaining four
corner screws.

6”

Connect by-pass pipe to collar and humidifier cabinet. Using
holes at top and bottom of side panel discharge, pierce 2 self
tapping screws through by-pass pipe.

4

Mount the self tapping saddle valve or code valve on either a cold
or a hot water pipe. A side or top mount is best to avoid clogging
from pipe sediment. Connect 1/4” O.D. tubing to the saddle valve.
Copper tubing requires a brass compression nut and brass sleeve.
Plastic tubing requires a brass insert inside the tubing, a plastic
sleeve on the outside with a brass compression nut.

NOTE: DO NOT USE PLASTIC TUBING ON HOT WATER OR IN
CONTACT WITH ANY HOT PLENUM SURFACE OR DUCT.
INSTALLATION OF THIS SADDLE VALVE MUST MEET OR
EXCEED LOCAL CODES AND ORDINANCES.

COPPER
TUBING

PLASTIC
TUBING

FORM NO. 900-18 REV. F

GCV3412 CODE VALVE INSTALLATION INSTRUCTIONS

Copper Pipe

1. Turn off water supply.

2. Clean pipe, fittings and valve with sandpaper or wire brush.

3. Apply a thin layer of flux to all surfaces to be soldered.

4. Assemble valve to pipe and/or fittings.

5. Cooling the valve by wrapping a wetted rag around the valve is
optional.

6. Heat the joints with a torch. Apply solder to each joint. Continue to
apply heat sufficient to keep solder liquid.

7. After solder has filled entire joint area, remove heat and allow joint
to cool. Do not move or disturb.

8. Slide compression nut over 1/4” copper tube followed by
compression sleeve.

9. Insert tube into valve fully and tighten nut.

10. Turn on water supply and check for leaks.

*CODE VALVE IS INCLUDED WITH AUTOMATIC MODELS ONLY

3/4” TEE

1/2” TEE

5

Connect 1/4" water supply tube to brass filter at inlet of solenoid.

NOT USE PLASTIC TUBING IN CONTACT WITH ANY HOT PLENUM
SURFACE OR DUCT. IF USING PLASTIC TUBING, USE TUBE INSERT
P189 AND PLASTIC COMPRESSION SLEEVE P190 (AVAILABLE AS
PART OF ASSEMBLY 747-38 TUBING KIT).

6

Turn damper knob to winter (open) position. Turn on water supply and check
operation of humidifier. Set humidistat to a demand setting. With the furnace
off, the solenoid valve should be closed. Start the furnace, the solenoid valve
should open when the blower or burner circuit is energized. Check flow of
water through distributor trough and evaporator pad. The standard GA4231
(YELLOW) orifice will supply approximately 3.5 GPH of water at a line water
pressure of 60 psi. For low water pressures (20-40 psi) a larger (ORANGE)
orifice GA4299 is available to provide the same flow. Leave humidistat set at
the recommended setting.

Connect drain hose to 1/2" spout on humidifier cabinet using hose clamp.
Run 1/2" hose to suitable drain such as floor drain, sewer or laundry sink.
Be sure hose has continuous slope and is not kinked at any point.

DO

7

SNSR

HUM

AC N

AC L

SNSR

HUM

AC N

AC L

HUMIDISTAT

HUMIDISTAT

OUTDOOR TEMP. SENSOR

WIRE JUMPER

WIRE JUMPER

OUTDOOR TEMP. SENSOR

WIRE

JUMPER

727-58 24 V. TRANSFORMER

24 V. TRANSFORMER

ON-OFF SWITCH

FURNACE

CONTROL BOARD

C

24v.
60CY.

R

N

115v.
(HOT)
60CY.

FURNACE

CONTROL BOARD

C

24v.
60CY.

HUM

ON-OFF SWITCH

W

W

FURNACE

BOARD

FURNACE

BOARD

(HOT)

ACC
EAC

24v.
60CY.

24V. SOLENOID VALVE

24V. SOLENOID VALVE

24V. SOLENOID VALVE

24V. SOLENOID VALVE

C

115v.
60CY.

7A

7C

7E

7G

SNSR

HUM

AC N

AC L

SNSR

HUM

AC N

AC L

HUMIDISTAT

OUTDOOR TEMP. SENSOR

WIRE

JUMPER

727-58 24 V. TRANSFORMER

24V. SOLENOID VALVE

OUTDOOR TEMP. SENSOR

WIRE

JUMPER

727-58 24 V. TRANSFORMER

C

12500 AIR

PRESSURE SWITCH

24V. SOLENOID VALVE

24 V. TRANSFORMER

ON-OFF SWITCH

NO

24 V. TRANSFORMER

HUMIDISTAT

ON-OFF SWITCH

C

PRESSURE SWITCH

ON-OFF SWITCH

12500 AIR

GA50

CURRENT

SENSING

RELAY

ON-OFF SWITCH

GA50

CURRENT

SENSING

RELAY

NO

L2

115v.
60CY.

(HOT)

L1

FURNACE

COMMON LEAD

C

(HOT)

L2

115v.
60CY.

(HOT)

L1

FURNACE

COMMON LEAD

C

(HOT)

115v.
60CY.

24V. SOLENOID VALVE

7B

C

HI
LO

115v.
60CY.

7D

24V. SOLENOID VALVE

C

HI
LO

MULTI
SPEED
BLOWER
MOTOR

7F

MULTI
SPEED
BLOWER
MOTOR

7H

7A-7D Electronic Humidistat

7A - To furnace control board 24 volts
7B - To constant power using 24V transformer and pressure switch
7C - To furnace control board 115 volts with 24V transformer
7D - To constant power using 24V relay and current sensing relay

7E-7H Manual Humidistat

7E - To furnace control board 24 volts
7F - To constant power using 24V transformer and pressure switch
7G - To furnace control board 115 volts with 24V transformer
7H - To constant power using 24V relay and current sensing relay

900-1 CHASSIS
900-9 NOZZLE
900-10 SPOUT

GA4266 DISTRIBUTOR TUBE

GA4040 SOLENOID VALVE ASM

GA4004 STAINER SCREEN

P102 COMPRESSION SLEEVE

P101 COMPRESSION NUT

P189 BRASS TUBE INSERT

PARTS LIST FOR HUMIDIFIER

900-40 PAD RAIL

GA-19 EVAPORATOR PAD

900-15 DISTRIBUTOR TROUGH

900-14 DRAIN PAN

GA4231 YELLOW ORIFICE

P102 COMPRESSION SLEEVE (BRASS)/P190 COMPRESSION SLEEVE (PLASTIC)

P101 COMPRESSION NUT

747-38 TUBING KIT (AVAILABLE)

900-11 DAMPER KNOB
900-28 DAMPER DISK
900-2 SIDE PANEL DISCHARGE

900-13 COVER

900-71 NAMEPLATE

LIMITED WARRANTY

This humidifier, if properly registered by the return of the warranty registration card to the manufacturer, is warranted to the consumer against defects in
materials and workmanship for a period of ten years from the date of installation. Evaporator pads, water strainers or metering orifices are not covered by this
limited warranty or any other warranties. Any other defective parts will be repaired without charge except for removal, reinstallation and transportation costs. To
obtain repair service under this limited warranty, the consumer must send the defective part or the complete humidifier to the manufacturer.

THERE ARE NO EXPRESS WARRANTIES COVERING THIS HUMIDIFIER OTHER THAN AS SET FORTH ABOVE, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY EXCLUDED. THE MANUFACTURER ASSUMES NO LIABILITY IN
CONNECTION WITH THE INSTALLATION OR USE OF THIS PRODUCT, EXCEPT AS STATED IN THIS LIMITED WARRANTY. THE MANUFACTURER WILL
IN NO EVENT BE LIABLE FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES.

This limited warranty gives you specific legal rights, and you may also have other rights which vary from state to state. Some states do not allow either
limitations on implied warranties, or exclusions from incidental or consequential damages, so the above exclusion and limitation may not apply to you.

Any questions pertaining to this limited warranty should be addressed to the manufacturer. (U.S.A.: The manufacturer has elected not to make available the
informal dispute settlement mechanism which is specified in the Magnuson-Moss Warranty Act.)

CARE AND MAINTENANCE

Your humidifier is engineered to give helpful and trouble-free humidification. For maximum efficiency the following cleaning procedures should be
carried out at the end of each heating season:

1. Turn off water supply and electrical power to humidifier.

2. Remove cover, distributor trough, evaporator pad and drain pan. Clean excessive mineral deposits from the distributor
trough, drain pan, pad rails, and humidifier cabinet. A solution of 1/2 vinegar & 1/2 water will help loosen mineral deposits.

Replace humidifier evaporator pad if necessary. (Part number GA19) Install trough and drain pan.

3.

Replace cover. Replace evaporator pad yearly for peak performance.

4. In heavy mineral areas or if the solenoid valve fails to function disconnect the 1/4” water supply line from the solenoid valve.
Carefully pull the strainer screen (P.N. GA4004) from the valve body (P.N. 900-6). Clean the mineral deposits from all
parts.
If the orifice is clogged, it may be opened by inserting a small pin. Reinsert the filter into the orifice fitting and screw the
brass strainer body into the solenoid valve.

5. Reconnect the 1/4” water line to the solenoid valve if necessary. Turn on the water supply and check all points for leakage.
The operation of the unit may be checked by starting the furnace. The humidifier operates only when the furnace blower is
running or the burner circuit is energized. The humidifier is now ready for operation.

6. During the summer, turn off water supply and electrical power to humidifier. Close air damper.

AT

OUTSIDE

TEMPERATURE

RECOMMENDED

SETTING

-20°F -29°C 15%

-10°F -23°C 20%
0°F -18°C 25%

+10°F -12°C
+20°F - 7°C

30%
35%

+30°F - 1°C 40%

HOW THE HUMIDIFIER WORKS

The operating principle of the humidifier is based on the most efficient and economical means of evaporating water to the air. The humidifier uses only 2.5 watts
of electrical power during operation, less than the smallest household light bulb. The heat necessary for evaporating water is produced by the furnace.

The water supply to the humidifier is controlled by the electric solenoid valve. The humidistat connected in series with the solenoid provides low voltage control
of the humidifier. The humidistat is designed for wall mounting in the living area or surface mounting on the return air duct. ELECTRICAL RATING: 24 VAC / 60
Hz.

Water flows through a strainer, is metered through an orifice to provide the proper amount of water, and is supplied to the evaporator pad by the distributor
trough. Approximately 200 CFM of air is by-passed from the warm air plenum through the humidifier and returned to the cold air plenum. Moisture is evaporated

to the air passing through the evaporator pad. Minerals are not blown into the air stream as occurs in atomizing humidifiers; they are left on the evaporator pad
where a high percentage is carried off with the waste water.

When the humidifier is installed and operating, no adjustments are necessary other than setting the control knob on the humidistat to the desired level of
humidification. Leave knob on the humidifier in "HI" or "WINTER" position. To turn the humidifier off, close water supply valve, switch electrical power off and turn

humidistat off. If furnace is used for summer cooling or ventilating set air damper on "LOW" or "SUMMER".

DO NOT SET RELATIVE HUMIDITY TOO HIGH DURING COLD WEATHER. EXCESSIVE HUMIDITY MAY CAUSE CONDENSATION ON WINDOWS OR IN
WALLS. REFER TO RECOMMENDED SETTINGS AS DESCRIBED IN THE HUMIDISTAT OWNERS MANUAL.

TROUBLESHOOTING

SYMPTOMS

Humidier will not operate

Proper voltage present at solenoid
valve (24 VAC) but no water ow

Humidier runs without
furnace operation or humidier
never shuts o

Too much humidity in home and/or
condensation on windows

Where can I purchase
replacement parts?

* Humidistat is generally located on furnace return plenum or on an inside wall in the living space.

1. Set thermostat to operate both furnace burner and blower. Operation may be necessary for system power.

2. Humidity level in home may be higher than humidistat setting. Increase humidity setting on humidistat.*
3 . Verify water supply is on.

4. Check for voltage at the solenoid valve. Voltage should be 24VAC. Bypass the humidistat if necessary to isolate
the solenoid valve circuit.

5. Verify wiring of humidier and humidistat.

1. Verify water supply is on

2. Verify metering orice is not obstructed. Very hard water with high mineral content may restrict the metering
orice in as little as one heating season. Replace metering orice if restricted. (part number GA4231)

1. Verify humidier and humidistat wiring. Humidier should operate with furnace burner or blower cycle.

1. Reduce the setting on the humidistat. Refer to CARE AND MAINTENANCE section of this manual to estimate a
humidity setting for the home based on outside temperature. *

1. Replacement parts can purchased through your authorized GeneralAire contractor or visit www.GeneralAire.com
for more information.

DIAGNOSTIC STEP

USA CUSTOMERS
General Filters, Inc.
43800 Grand River Ave.
Novi, MI 48375
www.GeneralAire.com
[e-mail]
Toll Free [phone]

TECHNICAL SUPPORT

CANADIAN CUSTOMERS
Canadian General Filters, Ltd.
400 Midwest Rd.
Toronto, ON M1P3A9 Canada
www.CGFProducts.com
[e-mail]
Tel. [phone]