GeneralAire GF-1042DMM Operating instructions

Model GF-1042DMM
Installation & Owners Manual
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• Installationbyanyoneotherthanaqualiedcontractorvoidsthewarranty.
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• Readourfullwarrantypolicyattheendofthisdocument.
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Model 1042LH Humidier Installation Manual
Page #
3
3
3
4-5
6
7
7
8
8
9
10
Subject
Specications
Unit Location
Additional Materials That May Be Necessary
Installation
Installing / Wiring The Control
Installation Final Steps
How the Humidier Works
Maintenance
Parts Drawing
Trouble Shooting
FAQ’s
Model 1042LH Table of Contents
WARNING!
This symbol indicates: IMPORTANT INSTRUCTIONS!
Failure to heed them can result in serious injury or death.
CAUTION!
This symbol indicates: IMPORTANT INSTRUCTIONS!
Failure to heed them can result in serious injury or material property damage.

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
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Model 1042LH Humidier Installation Manual
Unit Location
• WARNING: Disconnect electrical power before beginning installation.
•Do not install where temperatures fall below 32° F / 0° C or where plenum temperatures exceed 200° F / 93° C.
When wiring into a multi-speed blower circuit see Step 7D.
•The humidier 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 humidier may be mounted on the warm or return air
plenum with equal efciency.
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. Air pressure switch (Model GF-12500)
5. Current sensing relay (Model GF-GA50)
Specifications
•Model: GF-1042DMM Legacy Flow Through Humidifier
•Type: Flow Through
•GPD: 17 Based on 120° F / 49° C Plenum Temperature
•Warranty (Years): 5
•Replacement Vapor Pad®:GF-990-13
(Replace 1-2 times per season)
•Dimensions (Inches): 14 H x 15-1/8 W x 9 D
•Weight (Pounds): 13
•Home Size (Square Feet): To 3,000
•Installation: Warm Air Plenum / Right or Left
•Plenum Opening (Inches): 9-1/2 H X 13-5/8 W
•Bypass Duct (Inches): 6
•Pallet Qty: 30
•Cabinet Construction: UV-Stable Automotive Grade Plastic
•Humidistat: Models: GF-MHX3 (Included)
•Voltage: 24VAC
•In Box: Humidifier, Humidistat, Installation Instructions, Vapor Pad®, Parts Kit, Drain Hose,
Transformer, Metal Distributor Tube, Damper, 15’ 5/8” Drain Hose, Drain Pan, Solenoid
Valve

!
15-1/8” W
14” H
9” D
Installation Options:
•Warm Air Plenum
•Return Air Plenum
•Vertical or Horizontal
•Furnace or Air Handler
Return
Air
Warm
Air
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Model 1042LH Humidier Installation Manual
Installation
1. Select location on vertical surface of warm or return air
plenum for mounting humidifier. For plenum sizes 9 1/2"
to 15" use GP-1040AD adapter plate and five screws, 3
screws in top (supplied with DM model only). Affix
mounting template in place making sure the template is
level. Do not install humidifier or 6" bypass pipe where
the blanked off ends of a cooling coil will restrict air flow
to the humidifier. Extend horizontal centerline from
template to the adjacent plenum. Scribe 6” circle 10” to
15” from side of humidifier, on cabinet centerline, using
connecting collar as guide. Cut out center section of
template and 6” hole.
2. Install four sheet metal screws in the side mounting holes
until the heads project about 3/8". Hang the humidier
from the four screws. Adjust humidier until level and
tighten four screws. Install four sheet metal screws in the
remaining mounting holes. Tighten all 8 screws. Install
drain pan, evaporator pad and distributor trough.
3. Install connecting collar. Connect by-pass pipe to collar
and humidier cabinet. Using holes at top and bottom
of humidier bypass opening, screw by-pass pipe to
humidier cabinet.
Top Of Template
TEMPLATE FOR INSTALLING
BYPASS HUMIDIFIER
4. TIGHTEN SCREWS AND ADJUST HUMIDIFIER UNTIL LEVEL.
5. REMARK FOUR REMAINING HOLES IF NECESSARY.
6. REMOVE HUMIDIFIER, DRILL REMAINING HOLES AND CUT OUT CENTER SECTION OF
TEMPLATE.
WHEN INSTALLING ON BASEMENT TYPE FURNACE, EXTEND THIS LINE
FOR LOCATING HOLE ON ADJACENT PLENUM
IF FURNACE JACKET EXTENDS MORE THAN 3" OUTWARD FROM THE PLENUM SURFACE
ALLOW 4" CLEARANCE BELOW THIS LINE FOR EASY ACCESS TO DRAIN HOSE CONNECTION.
CUT ON THIS LINE
TEMPLATE NO. 1042-25
ALLOW 2 1/2 INCHES CLEARANCE
ABOVE THIS SURFACE FOR SERVICING
FOLLOW INSTRUCTIONS PACKED WITH HUMIDIFIER
1. REMOVE PROTECTIVE PAPER FROM BACK OF TEMPLATE AND STICK IN LEVEL POSITION.
2. CENTER PUNCH AND DRILL THE FOUR SIDE MOUNTING HOLES WITH A 1/8 " DIA. DRILL.
3. HANG HUMIDIFIER FROM FOUR SIDE SCREWS AND INSTALL DRAIN PAN, EVAPORATOR
PAD AND DISTRIBUTOR TROUGH.
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Model 1042LH Humidier Installation Manual
Installation, Cont.
6. Attach solenoid valve to side of humidier cabinet with ow
arrow pointing up, using thumb nuts provided. Do not reverse
brass ttings as valve will not function if ow is reversed.
Assemble distributor tube so that it is directed into the center
opening of the distributor trough cover. Connect 1/4" water
supply tube to brass lter at inlet of solenoid.
CAUTION:DO NOT USE PLASTIC TUBING IN CONTACT WITH
ANY HOT PLENUM SURFACE OR DUCT. IF USING PLASTIC
TUBING, USE TUBE SUPPORT PROVIDED.

!
4. Mount the Self-Tapping Saddle Valve.
5. Install the copper or plastic tubing.
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.
See gure to right.
Copper Pipe:
1. Retract piercing pin into valve body by turning handle counterclockwise.
2. Screw valve body into upper bracket and tighten.
3. Place rubber gasket over piercing pin.
4. Assemble saddle valve over copper pipe using enclosed screws, nuts and lower bracket.
5. Tighten screws evenly and firmly. Brackets should be parallel.
6. Complete compression connection to saddle valve outlet.
7. Turn handle clockwise to pierce tubing and close saddle valve.
8. Turn handle counterclockwise to open saddle valve, leave open for several seconds to flush dirt from pipe and tubing.
Steel, Brass or Hard Plastic Pipe:
1. Shut off water supply and drain pipe.
2. Turn handle clockwise to expose piercing pin and close saddle valve.
3. Place rubber gasket over piercing pin.
4. Drill 1/8" hole in pipe .
5. Assemble saddle valve over steel, brass or hard plastic pipe using enclosed screws, nuts and lower bracket.
6. Tighten screws evenly and firmly. Brackets should be parallel.
7. Complete compression connection to saddle valve outlet.
8. Turn handle counterclockwise to open saddle valve, leave open for several seconds to flush dirt from pipe and tubing.
Threaded Pipe Fittings:
1. Turn handle clockwise to expose piercing pin and close saddle valve.
2. Seal valve body threads using pipe tape or sealant.
3. Install valve into 1/8" NPT fitting.
4. Complete compression connection to saddle valve outlet.
5. Turn handle counterclockwise to open saddle valve, leave open for several seconds to flush dirt from pipe and tubing.
CAUTION: Turn off water supply.
CAUTION: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.
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!

!
COPPER
TUBING
PLASTIC
TUBING
Plastic
Sleeve
Brass
Insert
Brass
Sleeve
Compression
Nut
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Model 1042LH Humidier Installation Manual
Installing / Wiring The Control
WIRE JUMPER
7D
(HOT)
115v.
60CY.
ON-OFF SWITCH
COMMON LEAD
FURNACE
C
HI
LO
GA50
CURRENT
SENSING
RELAY
MULTI
SPEED
BLOWER
MOTOR
AC L
AC N
HUM
SNSR
24V. SOLENOID VALVE
727-58 24 V. TRANSFORMER
(HOT)
C
115v.
60CY.
ON-OFF SWITCH
AC L
AC N
HUM
SNSR
24V. SOLENOID VALVE
727-58 24 V. TRANSFORMER
L1
CNO
(HOT)
L2 115v.
60CY.
ON-OFF SWITCH
12500 AIR
PRESSURE SWITCH
AC L
AC N
HUM
SNSR
24V. SOLENOID VALVE
727-58 24 V. TRANSFORMER
R
FURNACE
CONTROL BOARD
C24v.
60CY.
AC L
AC N
HUM
SNSR
24V. SOLENOID VALVE
FURNACE
BOARD
W
WIRE JUMPER
OUTDOOR TEMP. SENSOR
OUTDOOR TEMP. SENSOR
OUTDOOR TEMP. SENSOR
OUTDOOR TEMP. SENSOR
N
W
24v.
60CY.
WIRE
JUMPER
WIRE
JUMPER
WIRE
JUMPER
6A6A 6B
6C 6D
1. Locate the humidistat at least 24" upstream of the
humidier or bypass on the return air duct. Avoid areas
of direct radiation like secondary heat exchangers in the
fan compartment.
2. Place template using level. Cut sensor hole as shown on
template. Drill four 3/32” holes (not shown).
3. Remove the housing from the base by prying with a
small screwdriver at the notch in the side of the housing.
4. Gaskets: Place the outer portion ONLY of the thin foam
gasket on the humidistat base and mount the base
with four screws. Place the thick gasket inside the wall
mount base to seal off air entering through the vents.
Low voltage wire may enter the humidistat under the
foam seal.
5. Connect wires to screw terminals on the control
assembly as shown in wiring diagram. Replace housing.
6.
GF-MHX3: DUCT Mounting (Return Air Duct)
CAUTION:Do not install the humidistat on the warm air duct.
6. GF-MHX3: WALL Mounting Instructions
1. Choose a location for the humidistat about ve feet
above the oor on an inside wall with average room
temperature and humidity conditions.
2. Drill a small hole in the wall and run low voltage wiring
to the location chosen. Pull about 6” of wire through the
hole. Plug the opening to prevent drafts from affecting
the humidistat operation. Remove the housing from the
base by prying with a small screwdriver at the notch in
the side of the housing.
3. Gaskets: Place the entire outer and inner portions of the
gasket on the base as shown. Do NOT install the thick
gasket inside the base.
4. Mount the base horizontally over the wires using level.
Attach directly to the wall, using four screws provided.
5. Connect wires to screw terminals on the control assembly
as shown in wiring diagram. Replace housing.

!

!WARNING: ALL WIRING SHOULD COMPLY WITH LOCAL ELECTRICAL CODES.
Thin Gasket
Face FIG. 1
WALL MOUNT: Use
Outer & Inner Portions
DUCT MOUNT: Use
ONLY Outer Portion
Mounting
Base
Thick Gasket
DUCT MOUNT ONLY
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Model 1042LH Humidier Installation Manual
7. Connect drain hose to 5/8" spout on humidier cabinet
using hose clamp provided. Run 5/8" hose to suitable
drain such as oor drain, laundry sink or to a condensate
pump (sold separately). Be sure hose has continuous
slope and is not kinked at any point.
8 Turn on water supply and check operation of humidier.
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 ow of water through
distributor trough and evaporator pad. The standard
GF-9903776 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 orifice GF-9903775 is
available to provide the same flow. Leave humidistat set
at the recommended setting.
Installation Final Steps
How The Humidifier Works
•The operating principle of the humidier is based on the most efcient and economical means of
evaporating water to the air. The humidier 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 humidier is controlled by the electric solenoid valve. The humidistat
connected in series with the solenoid provides low voltage control of the humidier. The humidistat is
designed for wall mounting in the living area or surface mounting on the return air duct.
•Water ows through a strainer, is metered through an orice to provide the proper amount of water, and is
supplied to the Vapor Pad®by the distributor trough. Approximately 200
CFM of air is by-passed from the warm air plenum through the humidier
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
humidiers; they are left on the evaporator pad where a high percentage
is carried off with the waste water.
•When the humidier is installed and operating, no adjustments are
necessary other than setting the control knob on the humidistat to the
desired level of humidication. Set knob on the humidier to "OPEN"
position. To turn the humidier off, close the water supply valve, switch
electrical power off and turn the humidistat off. If furnace is used for
summer cooling or ventilating set air damper on "CLOSED".
•CAUTION: 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.
At Outside
Temperature
Recommended
Setting
-20°F -29°C 15%
-10°F -23°C 20%
0°F -18°F 25%
+10°F -12°C 30%
+20°F -7°C 35%
+30°F -1°C 40%

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Model 1042LH Humidier Installation Manual
Maintenance
Your humidier is engineered to give helpful and trouble-free humidication. For maximum efciency the following
cleaning procedures should be carried out at the end of each heating season:
1. Turn off the water supply and electrical power to the humidifier.
2. Remove water distributor tube, distributor trough, used Vapor Pad®and drain pan. The Vapor Pad®may be
removed from either the top or bottom of the humidifier. Clean excessive mineral deposits from the distributor
trough, drain pan and humidifier cabinet. A solution of 1/2 vinegar & 1/2 water will help loosen mineral deposits.
3. Insert a new GF-990-13 Vapor Pad® (black notch on top). Install trough and drain pan. Replace the distributor
tube to proper position over the distributor trough. Replace Vapor 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. Remove the brass strainer body from the solenoid valve. Carefully pull the strainer screen
GF-990-17 from the orifice fitting. Clean the mineral deposits from all parts. If the orifice is clogged, it may be
opened by inserting a small needle. 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 the water supply and electrical power to the humidifier. Close the air damper.
Parts Drawing
1099-9 THUMB NUT
1137-35 TROUGH COVER
1137-4 DISTRIBUTOR TROUGH
1042-5 DISTRIBUTOR TUBE
990-13 EVAPORATOR PAD
CABINET ASSEMBLY
1042-16 (24 V.)
P-103 COMPRESSION NUT
P-104 COMPRESSION SLEEVE
P-111 CONNECTOR
SOLENOID VALVE ASSEMBLY
990-53 (24 V.)
990-37-76 ORIFICE & STRAINER ASSEMBLY
990-16-76 ORIFICE FITTING
990-17 STRAINER SCREEN
990-18 STRAINER BODY
1137-3 DRAIN PAN
P-163 HOSE CLAMP
1099-16 DRAIN TUBE

Model 1042LH Humidier Installation Manual
Troubleshooting
1. My humidifier continues to run.
Check for the following:
•The valve might be stuck in the "open" position.
•Check for wiring errors.
•Is the unit sized properly for your home? If it is rated for a smaller-sized home than the home in which it is
installed, it will work "overtime" to reach the humidification levels desired.
•Check the Vapor Pad®. If it is clogged, the pad will reduce the humidifier efficiency. Replace if necessary.
2. My solenoid valve is making a "chatter" noise.
This can be caused by any of the following:
•The power to the valve is less than 18V AC.
•The solenoid is causing a "water hammer condition" thru the water pipes (valve closes quickly and shuts off
water flow, which in turn creates pressure behind the valve that has no avenue of relief). You may want to install
a water hammering device with your plumbing, or contact your local plumber to determine the best solution.
•The humidistat is located too close to the humidifier or the by-pass pipe. Your humidistat should be a min. of
1.5' away or greater.
•The humidistat could have a buildup of dust, causing a faulty reading. Clean.
•The solenoid valve might be dirty. Remove, inspect and clean if necessary.
•Water supply pressure going to the valve may be too low.
•The hold down nut on top of the solenoid, as it may be loose.
3. The humidifier is not raising the humidity levels in my home.
Check for the following:
•Ensure you have changed / replaced your Vapor Pad®at the proper intervals (once per year) to ensure the
greatest production of moisture.
•Check the setting of your humidistat to ensure it is set higher than current humidity levels in your home (when in
doubt, turn it all the way to the right at maximum production). If you don't know what your current humidity
level is, use an instrument called a thermo-hygrometer (Model GF-610)to measure both heat and humidity
levels in your home.
•Calculate your humidity load (Gallons Per Day - GPD) via our humidity calculator (www.GeneralAireIAQ.ca).
Check to see that your humidifier model is designed to produce the amount of moisture (GPD) you need.
•Have you recently installed hardwood floors? Have you recently remodeled and added on to your home? These
can both increase your home's demand for humidity. Options include connecting your humidifier to the hot
water supply (which can increase output by as much as 30%), or installing a new humidifier model that can
generate more humidity.
•The unit is not recommended for heat pumps.
•Plenum temperatures must meet or exceed 120° F to achieve listed capacities.
4. My humidifier will not turn on.
The following might be occurring:
•Check to see if your humidifier is plugged in, that the breaker is engaged, and that power to other items from
the same source is working.
•Check that the damper knob is in the "OPEN" position.
•Ensure a fuse has not blown.
•Check that connectors are properly inserted in the terminal block.
•Make sure the furnace is operating in the heat mode.
To ensure your safety and the longevity of your unit, we recommend
contacting a licensed contractor to perform any repairs or maintenance.

!
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Model 1042LH Humidier Installation Manual
FAQ’s
1. How does a humidifier help with my allergies?
Dry air can lead to a host of problems for allergy and asthma sufferers. Dry climates, winter air, and articial
heat all contribute to the discomfort by drying out your skin, throat and delicate sinus passages and airways
(which can contribute to sinusitis). Winter is an especially bad time for dry air as home heating systems,
especially forced-air systems, reduce the amount of moisture in the air while humidity levels outdoors typically
dip as well.
2. What range of humidity is ideal?
Research shows that 40-60% relative humidity is ideal. Outside this range, your risk of being adversely affected
increases.
3. How often should I change my Vapor Pad®?
We recommend replacing your Vapor Pad®at least once per year. Minerals build up on the vapor pad over
time, which in turn:
•Reduces the pad's ability to absorb water.
•Prevents the warm air from owing through the pad. (Warm air moving though the water-soaked pad
causes the water in the pad to evaporate. It is this process that delivers moisture throughout your home
via the home's duct system.)
4. Can I clean my Vapor Pad®instead of replacing it?
A coating is applied to the Vapor Pad®that helps it absorb water and control water ow. If you subject the
Vapor Pad®to cleaning, you usually remove much of the coating and the pad becomes ineffective. This
reduces the output of the humidier and increases water consumption.
Replace the Vapor Pad®annually.
5. Why would I want to install a humidifier?
For many reasons:
1. Since the air in your home is always trying to reach its saturation point, it will absorb water wherever
it can; from the bodies of you and your children, your pets, your furniture and even your house plants.
As a result your skin, throat and nasal passages dry out, leaving you more susceptible to physical
discomfort, colds, u and even infection. Allergy and asthma sufferers can be especially affected by air
that's too dry.
2. Dry air causes dry, itchy skin.
3. Dry air cracks expensive woodwork, oors, musical instruments, artwork and furnishings.
4. Annoying static electricity (caused by dry air) can damage computers, VCR’s and other electronic
equipment, requiring expensive repair.
5. Dry air can cause harm to expensive musical instruments like pianos and violins.
6. Dry air causes gaps in window & door frames, letting cold outdoor air in; causing you to turn up the heat
and increasing your heating bills! Controlled humidity from a GeneralAire®Humidier allows you the
luxury of dialing the thermostat back & reducing annual heating bills. For example, 68° at 40% relative
humidity feels just as warm as 74° at 20% humidity. Setting your thermostat back by as little as three
degrees can reduce annual heating bills by as much as 5%.
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