BestAir PRO GH2500 Quick start guide

1
SEQUENCE OF OPERATION
RECOMMENDED LOCATION
TEMPERATURE AND SAFETY REQUIREMENTS
HUMIDIFIER MOUTING LOCATION
Installation Instructions
Owner’s Manual
STEP BY STEP INSTALLATION
DRILL MOUNTING HOLES AND CUT OPENING
MODEL GH2500
MOUNTING HUMIDIFIER
HUMIDISTAT MOUNTING LOCATION
MODEL GH2500 SCOOP HUMIDIFIER
Refer to the rating plate on the furnace for minimum
clearances to combustible construction. All parts and
connections of a BestAir PRO humidifier must be
installed outside of the minimum clearance require-
ments for rear, top, sides, and flue of furnace. Do not
install where humidifier or water connections may be
exposed to freezing temperatures or outside weather.
Attic installations are NOT recommended. If you have
central air conditioning, carefully plan the location of the
plenum opening to prevent damage to the cooling coil or
other components inside the duct.
The BestAir PRO model GH2500, is to be mounted on
the supply duct of the furnace only.
The BestAir PRO Model GH2500 use the evaporative
principal to add moisture to the warm air heating system.
Upon a demand for humidity from the humidity control,
the water solenoid valve opens and water flows in at the
top of the media pad and is evaporated, as warm air
passes through the media pad. When the moisture
laden air re-enters the duct it is mixed with dry air already
flowing through the duct. This moisture laden air gradu-
ally increases the relative humidity level in the home.
CAUTION:Installation should be performed by
qualified personnel only. Use eye protection and
gloves when drilling and handling sheet metal. All work
must be performed to local & national codes and ordi-
nances. Use multi-conductor 18 awg solid copper wire.
Provide over-current protection as required. DO NOT
omit the drain or overflow tubing.
Turn off power to the furnace before installing the
humidifier. Test fit the GH2500 housing on the side of
the warm air plenum. Before proceeding, verify that
adequate clearances are available for servicing the
media pad. There must also be adequate room (5 1/2
inches) inside the plenum for the louver. If necessary,
relocate the unit. Use a plumb line or a level to make
sure the housing is level. With a permanent marker
outline the inside edge of the housing. Also mark the
twelve holes to be drilled. Center punch and drill all
twelve holes as indicated by the marks. Drill or punch
a starter hole and then use tin snips to cut out the rect-
angular shaped opening. The opening should be 1/8
inch larger on all four sides than what was marked.
Hold the housing next to to duct and start four #8 x 3/4
inch long sheet metal screws through the holes in the
bottom edge of the humidifier. With these four screws
started the unit should remain in place while starting
the other eight screws. With all twelve of the screws
started they can now be tightened. With the housing
mounted the louver can be installed. This should be
done by rotating the louver to the proper position
depending on the direction of air flow. The air flow
should enter into the curved multi-louvers and exit out
of the large opening.
The humidistat can be mounted on the cold air return
duct to sense the cool dry air returning to the furnace. It
can also be mounted on an interior wall near the furnace
thermostat as well. The electrical connections and basic
wiring are the same for duct mounted or wall mounted
humidistats.
TB 218 Part#090375A0218-GH12122006GH2500
FOR USE WITH GAS, OIL, and HYDRONIC FORCEDAIR FURNACES
®Copyright 2007 © , All Rights Reserved
281 Keyes Ave. Hampshire, IL 60140 • 847-683-7990 • Fax [phone] • www.bestairpro.com
®
TM
GH2500 mounts
to the supply
duct only.
Horizontal flow
GH2500 Blower
Motor
Side Cutaway View
Model GH2500mounted
on the supply plenum
of an Upflow Furnace
Up Flow
GH2500

2
PARTS LIST
MODEL GH2500
1. Model GH2500 Humidifier
2. Small parts bag containing:
a. Two #8 x 3/4” sheet metal screws
b. Twelve #8 x 3/8” sheet metal screws
3. Saddle tapping valve kit
4. 24 volt humidistat
5. 24 volt transformer
6. 1/2” drain hose
7. 1/4” plastic tubing
8. Evaporative media pad
9. Owner’s manual
ADDITIONAL RECOMMENDED PARTS
1. Relay, with 120 volt current sensing coil for furnaces
with multi-speed blower motors.
2. 4x4 wire box to mount transformer and enclose line
voltage connections.
3. #18awg thermostat wire to make up and and all
24 volt connections
4. 1/2” drain hose clamp.
Copyright 2007 © , All Rights Reserved
281 Keyes Ave. Hampshire, IL 60140 • 847-683-7990 • Fax [phone] • www.bestairpro.com
®
®
Unpack the BestAir PRO model GH2500 humidifer and familiarize yourself with the following parts:

C
T40-VA
24VAC40VA
OREQUIVALENT
3
ELECTRICAL CONNECTIONS
BESTAIR PRO MODEL GH2500 FLOW-THRU HUMIDIFIER
The transformer should be wired in parallel with the
furnace blower motor line voltage. This will allow the
humidifier to run only when there is a call for fan.
The transformer is designed to be attached to a 4”
square outlet box. The electrical box must be
mounted and wired in accordance with local building
codes & the National Electrical Code. SHUT OFF
THE POWER TO THE FURNACE BEFORE PRO-
CEEDING! NOTE1: Check wiring in furnace for
humidifier (HUM) terminals. If present, check to see
if it is 120vac or 24vac. If it is 120vac, connect the
transformer primary leads to these terminals. If it is
24vac, you do not need the transformer. Simply
connect one side of the humidistat to one HUM
terminal and the other HUM terminal to the solenoid
valve of the humidifier. Then make the last connec-
tion of the solenoid valve to the humidistat. If you
are using the transformer you will need to connect
the 24vac common from the transformer to one of
the solenoid valve wires and then the 24vac hot from
the transformer to the humidistat. Then from the
humidistat to the other wire on the solenoid valve.
Make sure not to route wires where they can be
burned or chaffed. See example wiring solutions to
the right of this page.
OPERATIONAL CHECK
With the humidistat set to its highest setting the
humidifier solenoid should open shortly after the
furnace blower is activated. If solenoid does not
open refer to troubleshooting guide in this manual.
CAUTION: Check the transformer, the solenoid
valve and humidistat as well as all field wiring
connections as they could be at fault.
A qualified Electrician should be consulted to
determine if 24 vac is present at the solenoid and
at the humidistat, and that line voltage is present
at the transformer.
WIRING FOR MOST COMMON FURNACES
WIRING FOR MOST COMMON 2 STAGE OR
VARIABLE SPEED FURNACES
T40-VA
24VAC 40VA
OR EQUIVALENT
C
H
HUMIDISTAT
L1
L2
Solenoid Valve on
Model GH2500
To Motor current sensing
relay NO Contact
TO
LINE
VOLTAGE
HUMIDISTAT
If the HUM terminals
in the furnace are
24vac, don’t use the
transformer! Simply
connect to the HUM
terminals as shown.
HUM
H
HUM
To 120 vac HUM
terminals in furnace.
See Note 1.
Copyright 2007 © , All Rights Reserved
281 Keyes Ave. Hampshire, IL 60140 • 847-683-7990 • Fax [phone] • www.bestairpro.com
®
®
Solenoid Valve on
Model GH2500

4
WATER CONNECTION
Water supply for the humidifier should be taken from
a nearby hot water line but cold water is acceptable.
All water connections should be made at ground
floor level. Do not use any water line served by a
water softener. If your home has a water softener,
make the water connection up stream of the water
softener. A water softener is not a de-mineralizer. It
merely exchanges various hard-ions for soft-ions in
the water. These soft-ions or minerals, will build up
in the transfer media in the humidifier, causing the
need for more frequent servicing. The evaporation
of softened water may also produce a white powder
which may be carried in to the duct system and
ultimately in to the home. The saddle tapping valve
should be mounted on top of, or on the side of the
water line. If the valve is installed on the bottom of
the water line it could clog with sediment from the
water line. Refer to the instructions on the saddle
valve package and proceed as follows. For copper
water lines the valve is self piercing. Mount the
saddle valve to the top or side of the water line, then
turn “T” handle to the clockwise until it stops to
pierce and seat the valve to the pipe. Open to flush
the valve and close it again. Then connect plastic
water line from the valve to the humidifier making
sure not to kink it or run it near any hot flue pipes.
Connect water line to valve and humidifier with
supplied hardware. Now open the saddle valve turn-
ing the tee handle counter clockwise until fully open.
Check for water leaks and repair as necessary.
Attic installations are not recommended
INSTALL DOOR AND EVAPORATIVE PAD
DRAIN CONNECTION
Make sure the evaporative pad is positioned in the
door correctly. The black mark on the edge of the
pad indicates the top. The pad slides into the door
and rests against the four legs located inside.
Position the bottom edge of the door in the tray
located on the lower opening in the housing. Then
simply push the top of door closed until is has
snapped into place. To remove door just push down
on the two tabs located at the top of the door and pull
the door away from the housing.
Connect the 1/2” plastic tubing to the drain spout
and secure it. The spout is located at the bottom of
the housing. Keep the tubing as short as possible
and avoid sharp bends. The drain line should be
routed on a continous downward slope and into a
suitable drain. WARNING: failure to connect the
drain tubing could result in a flood.
SETTING THE HUMIDISTAT
Most people feel comfortable between 35% to 45%
RH, but the proper relative humidity for your home
depends upon many factors such as outside air
temperature, type, and placement of insulation,
vapor barrier, effectiveness of weather stripping,
type of windows and doors (including frames and
jams), and whether storm windows and doors are
used. With all of these variables it is nearly impos-
sible to recommend a proper humidity setting. The
best humidstat setting is one that you are comfort-
able with. Also, as the outdoor temperature fluctu-
ates, it may be necessary to adjust the humidity
level a few times during the heating season. Refer
to the “Relative Humidity Chart” as a starting point
for your proper humidistat setting. Generally, in a
tighter and better insulated house, the humidistat
may be set higher than in a drafty, uninsulated
house.
Copyright 2007 © , All Rights Reserved
281 Keyes Ave. Hampshire, IL 60140 • 847-683-7990 • Fax [phone] • www.bestairpro.com
®
®
BESTAIR PRO MODEL GH2500 FLOW-THRU HUMIDIFIER
INSTALL HUMIDISTAT
The BestAir PRO Humidistat should be installed as
described in the installation instructions supplied
with the humidistat.

5
DO NOT OVER - HUMIDIFY
MAINTENANCE
Cold air cannot hold as much moisture as warm air.
Any cold drafts or cold-faces such as windows and
doors (including frames and jams) may cause water
vapor to condense at these points. Also, if your
home is well-insulated and weather-stripped but
lacks effective vapor barriers, water may seep
through the walls and ceilings. This moisture may
condense either inside or outside the walls or in the
attic. If any of these conditions are observed, the
humidity level should be reduced before water
damage occurs.
RELATIVE HUMIDITY CHART
Suggested Humidistat Settings
OUTDOOR
TEMPERATURE
ADJUST
%RH TO
+30°F
+20°F
+10°F
+0°F
-9°F
40%
35%
30%
25%
20%
Table 1. Suggested RH set points for different outdoor temperatures
All power humidifiers require some mainte-
nance to keep them operating at peak perfor-
mance. The BestAir PRO model GH2500 humidi-
fier has been designed to simplify required
maintenance.
1. Semi-annual or annual replacement of the
evaporator pad.
2. An annual cleaning, general inspection, and shut
down of the unit at the end of the heating season.
3. The evporative pad should be replaced when it
starts to look white and chalky. Replace it with a
catalog #SC-EP pad.
Copyright 2007 © , All Rights Reserved
281 Keyes Ave. Hampshire, IL 60140 • 847-683-7990 • Fax [phone] • www.bestairpro.com
®
®
TM

6
SYMPTOM
T R O U B L E S H O O T I N G
POSSIBLE CAUSES & REMEDIES
Water does not flow when solenoid
is energized. 1. Saddle valve “T” handle is not open. 2. Saddle valve is clogged with mineral buildup.
3. Solenoid valve inlet screen is clogged.
4. Solenoid valve is stuck closed.
Solenoid will not energize. 1. Humidity control is not set high enough.
2. Control transformer has failed
3. HVAC system is not in the heating mode.
4. Fan motor interlock is faulty or miswired.
5. Faulty or incorrect field wiring.
6. Solenoid coil is faulty.
No water flows out of the drain tube. 1. Drain tube is kinked or blocked with debris.
RH level in the home is low or will
not rise. 1. Humidity control is set to low. 2. Water supply has been turned off.
3. Media pad is clogged with mineral buildup.
4. Media panel is installed incorrectly.
5. Solenoid valve is not opening or is faulty.
6. Heating system is drying out the house faster than the humidifier
can replace it. A sign of extremely cold outside termperatures or
the unit is undersized for the space.
7. Obtain a reliable & accurate Hygrometer to determine the RH level
in the home.
TECHNICAL SUPPORT
Troubleshooting support for the BestAir PRO products when you are on the job site. Call 1-847-683-7990 Monday-Friday
8AM to 5PM CST or for information on any BestAir PRO products including model GH2500
281 Keyes Ave. Hampshire, IL 60140 • 847-683-7990 • Fax [phone] • www.bestairpro.com
®

7
SERVICE NOTES
Copyright 2007 © , All Rights Reserved
281 Keyes Ave. Hampshire, IL 60140 • 847-683-7990 • Fax [phone] • www.bestairpro.com
®
®

8
SERVICE NOTES
Copyright 2007 © , All Rights Reserved
281 Keyes Ave. Hampshire, IL 60140 • 847-683-7990 • Fax [phone] • www.bestairpro.com
®
®