Wiring
Testing the System
1. Re-assemble system and check all connections.
2. Restore power to the HVAC system.
3. Start HVAC System by raising thermostat setting.
4. Check to see that GFX4 display is on.
5. Set to TEST MODE by pressing “Drop” and
“thermo” together for 5 seconds. The relay will
close and the “+” will flash for 2 minutes or press
a key to set to OFF MODE.
6. Set to OFF mode to verify humidifier operation
ceases.
7. The GFX4 will stay in OFF Mode unless set to
Manual or Automatic mode. See “Operation”.
PUSH
5 SEC.
BLINK !
Operating Modes
Press any button to light the display. Press the “DROP”
button to select the Operating Mode, Off, Manual or Auto.
OFF Mode
The Humidifier is turned off.
MANUAL Mode
The GFX4 will work to maintain the single
humidity selected. You can set your desired
humidity level by pressing “UP” or “DOWN”.
The humidifier will turn ON or OFF according
to your manual setting. The humidifier will
operate when the measured relative
humidity falls more than 1% below the set point until
the measured relative humidity is 1% above the set
point. When the humidifier is operating, the “+” will
display. Humidity may have to be lowered when
weather is colder or if condensation is suspected. The
settings table to the right or a similar table may be used
to compensate for cold outside temperatures.
Outdoor Suggested
Temperature Setting
15%
20%
25%
30%
35%
40%
-29°C
-23°C
-18°C
-12°C
- 7°C
- 1°C
-20°F
-10°F
0°F
+10°F
+20°F
+30°F
Display a Temperature
Press the “THERMOMETER” button to move between displaying indoor and
outdoor temperature. “Tree” will be displayed when showing outdoor
temperature. “House” will be displayed when showing indoor temperature. To
change between °F and °C units, press the “ °F/°C ” button.
Limited Warranty
This humidistat is warranted to the consumer against defects in materials and workmanship
for a period of one year from the date of installation. 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 to the
manufacturer.
There are no express warranties covering this humidistat other than set forth above. The
implied warranties of merchantability and fitness for a particular purpose are limited in
duration to one year. The manufacturer assumes no liability in connection with the
installation or use of this product, except as stated in this limited warranty. The manufac-
turer will in no event be liable for incidental or consequential damages.
Any questions pertaining to this limited warranty should be addressed to the manufacturer.
USA: The manufacturer has elected not to make available the informal dispute settlement
mechanism which is specified in the Magnuson-Moss Warranty Act.
Technical Support
Canadian General Filters, Ltd.
400 Midwest Road Toronto,
ON M1P3A9 Canada
www.
GeneralAireIAQ.ca
Tel 416-757-3691
FORM GFX4-11 Rev. A 9805-100-001
Trouble Shooting
“HOUSE” Flashing
The indoor temperature sensor has failed.
“TREE” Flashing
The outdoor temperature sensor has failed.
Humidifier Turns On and Off Repeatedly
Check that input voltage is between 18 and 30 volts, AC and not intermittent.
Check that humidistat is NOT mounted: 1. on supply duct. 2. downstream of
humidifier. 3. closer to humidifier than 12 inches.
Make sure that Outdoor Sensor wiring is not close to line voltage wires.
Humidifier Runs Continuously
If humidifier operates while HVAC system is off, check that power to humidifier
is switched with HVAC operation.
If humidifier operates every time HVAC System runs, compare humidity to set
point. If humidity is lower than set point, humidistat will call for operation.
Humidifier Does Not Run
Check wiring to/from GFX4 control. Verify 18-30 volts. Use “TEST MODE” .
Humidifier Runs When Air Conditioning Is On
If this is undesirable, change wiring to be powered only in heating periods.
Humidity not high enough
Fault with Humidifier. Check humidifier, water supply, electrical connections.
HVAC operating time too short. Check humidifier trouble shooting.
Humidifier undersized. Review humidity load and humidifier capacity.
Humidity Too High
Wiring fault. Set GFX4 to “OFF” mode and check that operation ceases.
Outdoor sensor is being kept warm. Check that sensor is not buried in snow,
on south side of house being warmed by sun or is too far inside of air intake.
AUTO Mode
The GFX4 will automatically raise the humidity as the outdoor temperature increases.
This provides the highest possible humidity. The GFX4 will automatically lower the
humidity as temperatures drop. This minimizes the risk of condensation on cold
surfaces like windows.
The Auto Humidity Index Set Point may be changed from 0 (low) to 10 (high) by
pressing “UP” or “DOWN”. The Humidity Index is based on the outdoor temperature
and indoor humidity. The humidifier will switch ON/OFF according to the calculated
auto humidity index set point. When the humidifier is operating, the “+” will display.
Lower Index settings are for older homes with less insulation and poor vapor barriers.
Higher Index settings are for newer homes with complete vapor barriers, triple pane
windows and high R value insulation.
1-2
Older than 1950, no vapor barrier, little insulation.
3-4
Built 1950-1965, no vapor barrier, R6 insulation.
5-6
Built 1965-1975, craft vapor barrier, R11 insulation.
7-8
Built 1980-1990, craft vapor barrier, R19, double pane windows.
9-10
Built after 1990, poly vapor barrier, R38 insulation, foam exterior cladding,
triple pane windows.
If condensation is seen or suspected, reduce index by 2 until condensation stops. The
level bars indicate the humidity index; one bar for two index points.
“DROP”
“UP”
“DOWN”
OFFSET Mode
To change the calibration of the GFX4, an offset may be entered to the Humidity,
Indoor Temperature or Outdoor Temperature displays. Press both “UP” and
“DOWN” buttons together to enter OFFSET mode. The word “OFFSET” and “RH”
will display. Press “UP” or “DOWN” to change the humidistat’s Humidity
calibration. Press both “UP” and “DOWN” buttons together again to change the
Indoor Temperature offset. Press both “UP” and “DOWN” buttons together again
to change the Outdoor Temperature offset.
Humidity
Outdoor Temperature °F
Index
-20
-10
0
10
20
30
40
50
1
0
5
10
15
20
25
30
35
2
3
8
13
18
23
28
33
38
3
6
11
16
21
26
31
36
41
4
9
14
19
24
29
34
39
44
5
12
17
22
27
32
37
42
47
6
15
20
25
30
35
40
45
50
7
18
23
28
33
38
43
48
53
8
21
26
31
36
41
46
51
56
9
24
29
34
39
44
49
54
59
10
27
32
37
42
47
52
57
62
AUTO Mode Target Humidity
WIRING OUTDOOR SENSOR
SPLICES: NO
MORE
THAN ONE
PER LEAD
200 FEET MAX.
NOTE: Separate sensor leads from
line voltage wires by at least 4 inches.
FIELD
SUPPLIED
SNSR 2
SNSR 1
FAN 2 (GF)
FAN 1 (GT)
HUM 2
HUM 1
AC C
AC L
(R)
SNSR 2
SNSR 1
FAN 2 (GF)
FAN 1 (GT)
HUM 2
HUM 1
AC C
AC L
(R)
SNSR 2
SNSR 1
FAN 2 (GF)
FAN 1 (GT)
HUM 2
HUM 1
AC C
AC L
(R)
SNSR 2
SNSR 1
FAN 2 (GF)
FAN 1 (GT)
HUM 2
HUM 1
AC C
AC L
(R)
WIRING TO FAN POWER HUMIDIFIER
CONSTANT
24 VOLTS
YELLOW
YELLOW
120 VOLTS
SWITCHED
W/ FURNACE
OPERATION
TO FURNACE
BLOWER
WIRING TO 24V. HUMIDIFIER
CONSTANT
24 VOLTS
24 VOLTS
SWITCHED
W/ FURNACE
OPERATION
24 VOLT HUMIDIFIER
SOLENOID VALVE OR
DRUM MOTOR
WIRING TO STEAM HUMIDIFIER
N2
GND
N1
AB
AB
GND
IN
NO
C
NC
C
NO
GND
24V
EXT FAN
ALARM
JUMPER
JUMPER
JUMPER
JUMPER