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Automatic Mode
Immediately after installation, the universal humidistat
must be set to match your home’s condition. Follow these
steps to adjust the automatic humidifier control. See
figure 2.
FIGURE 2
CONTROL
KNOB
UNIVERSAL HUMIDISTAT
PAD
REPLACEMENT
TIMER RESET
BUTTON
7
6
5
4
3
2
1
NORMAL
OFF
HUMIDIFIER
CONTROL
TEST
1 − Turn the knob to setting 5, which is within the normal
range. During the next 24 to 48 hours, it may be
necessary to adjust the dial for more or less humidity,
depending on your personal comfort and the home’s
requirements. See table 2.
TABLE 2
Operation Guide
Condition
Solution
Condensation on windows.
Reduce the setting on the control
dial by one increment at a time.
Lack of humidity.
Increase the setting on the control
dial by one increment at a time.
Humidifier does not operate.
(solenoid does not click" when
control is moved to
TEST
position.)
Make sure power is available to the
solenoid valve. Turn dial to
TEST
.
Make certain furnace blower is
operating and furnace is calling for
heat. If unit still does not operate,
consult a heating contractor.
Humidifier won’t shut off
Turn dial to
OFF
. If unit continues to
operate, consult a heating
contractor.
Test Mode
System operation is checked by
setting the knob to
TEST
. Make
certain that the furnace blower is
operating and furnace is calling for
heat. Humidifier will operate for one
minute.
2 − During the coldest portion of the first heating season,
minor adjustments may be necessary, depending on
the home’s construction. See table 2.
The RH in your home will be accurately controlled to meet
your needs and should not need further adjustment
during future heating seasons. Make note of the dial
setting in the event the knob gets moved.
Your humidifier is part of a system that will accurately
maintain the RH in your home. For every 1
°
F change in
outdoor temperature, the universal humidistat will
automatically adjust the indoor relative humidity by 0.5%
RH. If you would like to determine the RH in your home,
follow these steps:
1 − Determine the outdoor temperature.
2
− Activate the furnace blower by setting your
thermostat fan switch to the
ON
position, or by setting
your thermostat to a higher temperature.
3 − Turn the control dial setting to the
OFF
position.
Then, slowly turn the dial clockwise until you hear the
solenoid valve click on. Slowly turn the dial
counterclockwise until you hear the solenoid valve
click off. At this point, make note of the dial setting.
4 − Locate your dial setting on table 3. Follow the dial
setting to the right until it intersects with the current
outdoor temperature. This is the RH in your home
under existing conditions.
5 − Return the thermostat and control to their original
settings.
TABLE 3
Percentage Relative Humidity (RH)
Outdoor Temperature (
°
F)
Dial
Setting
−10
0
10
20
30
40
1
10
10
10
15
20
25
2
10
10
15
20
25
30
3
10
15
20
25
30
35
4
15
20
25
30
35
40
5
20
25
30
35
40
45
6
25
30
35
40
45
45
7
30
35
40
45
45
45
As an example, if the outdoor temperature is 20
°
F and,
following step 3, the humidifier turns off at 5"on the dial
range, then the RH in your home is 35%.
The universal humidistat will accurately control the
humidity in your home to a maximum of 45% RH and a
minimum of 10% RH. The values of outdoor temperature
and dial settings may fall in between or outside of the
listed values in table 3. In these cases, you will be able to
approximate your home’s actual indoor RH.
Manual Mode
If an outdoor temperature sensor has not been installed
with your universal humidistat, the control is installed in
the cold air return and is set for manual mode operation.
In this case, it is important to keep the humidistat setting
at the recommended level in order to avoid excessive
indoor RH. This will prevent the formation of
condensation on inside windows (fogging or frost on
windows). For example, with an outside temperature of
20ºF the correct setting will be 35% RH. If the temperature
is expected to fall to 0ºF that evening, then adjust the
setting to provide 25% RH several hours prior to the
temperature change.
FIGURE 3
UNIVERSAL HUMIDISTAT IN MANUAL MODE
CONTROL
KNOB
PAD
REPLACEMENT
TIMER RESET
BUTTON
