Aprilaire 800 Series User manual

Includes Safety & Operating
Instructions and
Warranty Information
Series 800
Steam Humidifier
Owner’s Manual
READ AND SAVE THESE INSTRUCTIONS
10016602 B2210090A 09.22

TABLE OF CONTENTS
Safety Cautions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Principles of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Installation Options and Effect of Water Characteristics. . . . . . . . . . . . . . . . . . . . . . 6
Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Display Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Operating Instructions –
Model 62 Automatic Digital Humidifier Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Operating Instructions –
Model 65 Manual Digital Humidistat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Operating Instructions –
Model 63 Automatic Digital Modulating Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Additional Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Limited Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
SAFETY CAUTIONS
CAUTION
READ ALL CAUTIONS AND INSTRUCTIONS
Read this manual before performing service or maintenance procedures on
any part of the system. Failure to follow all cautions and instructions could
produce the hazardous situations described, resulting in property damage,
personal injury, or death.
Failure to follow the instructions in this manual can cause moisture to
accumulate, which can cause damage to structures and furnishings.
CAUTION
HOT SURFACES AND HOT WATER
This steam humidification system has extremely hot surfaces. Water in
steam canister, steam pipes, and dispersion tube can be as hot as 212°F
(100°C). Discharged steam is not visible. Contact with hot surfaces,
discharged hot water, or air into which steam has been discharged can
cause severe personal injury. To avoid burns, follow procedures in this
manual when performing service or maintenance procedures on any part
of the system.
ELECTRICAL SHOCK HAZARD
Follow the shutdown procedure in this manual before performing service
or maintenance procedures on any part of the system. If the humidifier
starts up responding to a call for humidity during maintenance, severe
bodily injury or death from electrical shock could occur. Follow the
procedures in this manual before performing service or maintenance
procedures on this humidifier.
EXCESS HUMIDITY
Do not set humidity higher than recommended. Condensation may cause
damage.
English 32 English

INTRODUCTION
Thank you for your recent Aprilaire® humidifier purchase. We appreciate your
business and are pleased to add your name to our growing list of customers.
You have invested in the highest quality equipment available. Aprilaire
manufactures whole-house indoor air quality products and is a recognized
leader in the heating and air conditioning industry.
Your humidifier will require periodic maintenance to assure continued consistent
performance. See page 20.
Please take a few minutes and read this booklet. This will familiarize you with
the benefits you will receive from the humidifier and help you understand the
routine maintenance that will be required.
Be sure to register your humidifier warranty online at:
www.aprilaire.com/warranty.
Genuine Aprilaire Replacement Steam Canisters are available from your
installing contractor or from most other heating and air conditioning
contractors in your area. Use the dealer locator on our web site
(www.aprilaire.com).
PRINCIPLES OF OPERATION
The Aprilaire® Steam Humidifier delivers humidity in the form of steam to
the conditioned space via the HVAC system duct or Aprilaire Fan Pack. The
humidifier generates steam by energizing 2 electrodes that extend into a
canister of water. Current flowing between the electrodes causes the water to
boil, creating steam. Water is introduced to the humidifier through a fill valve
to a fill cup located in the top of the cabinet. The fill cup serves as an overflow
reservoir and provides an air gap between the humidifier and water source. The
steam canister is filled from the bottom. The canister is seated in a drain cup
assembly which includes a drain valve. The drain and fill valves work together to
maintain water level in the canister to deliver the rated steam capacity based on
the electrical conductivity of the water and to temper drain water. See FIGURE 1
for representation of fill and drain system and canister.
Steam is delivered into the airstream through a dispersion tube mounted
in the HVAC system ductwork. Openings in the dispersion tube are fitted
with “tubelets™” which extend into the center of the tube. The design of the
dispersion tube and tubelets distribute steam over a wide area in the duct and
direct any condensed moisture back into the steam hose.
STEAM
OUTLET
DRAIN
SUPPLY
WATER
DRAIN CUP
DRAIN VALVE
CANISTER
ELECTRODES
HIGH WATER
LEVEL SENSOR
FLOW CONTROL
ORIFICE
INLET
FILL VALVE
OVERFLOW
FILL
FILL CUP
90-1522
FIGURE 1 – FILL AND DRAIN SYSTEM AND CANISTER
SEQUENCE OF OPERATION
When the humidifier control detects the need for humidity, and provided the
humidifier is turned on and the HVAC system blower is operating, the internal
controller in the humidifier energizes the electrodes and measures the current
flowing through the water between them. The controller adjusts water level
in the canister via a fill valve and a drain valve to maintain a constant current.
The operating water level in the canister depends on the mineral content of the
water which determines conductivity.
English 54 English

INSTALLATION OPTIONS AND EFFECT OF
WATER CHARACTERISTICS
Your steam humidifier can be powered with a 120, 208 or 240 volt circuit and
operated at either 11.5 or 16.0 amps. The higher the voltage and amperage the
higher the potential output. The operating voltage and amperage are set by
your installing contractor to meet the humidification needs of your home.
Amperage Voltage Maximum steam capacity (gal/day)
11.5
120V 11.5
208V 20.5
240V 23.3
16.0
120V 16.0
208V 30.0
240V 34.6
It may take several days for the humidifier to reach rated capacity depending
on the input voltage and the electrical conductivity of the water. 120
volt systems take longer to reach rated capacity than 240 volt systems. The
humidifier should always be plumbed to cold water but the water can be
softened or unsoftened. “Hard” water, which has a high mineral content, and
softened water generally have higher conductivity than naturally soft water.
Systems plumbed to higher conductivity water will reach capacity sooner
than systems plumbed to low conductivity water. As the humidifier operates,
minerals build up in the canister, which increases the conductivity of the water.
With a new canister, allowing the humidifier to operate continuously (along
with the HVAC system blower) will allow it to reach rated capacity in the
shortest amount of time.
Canister life is highly dependent on water quality. Canisters in systems plumbed
to water with high concentrations of suspended and dissolved solids will not
last as long as canisters operating on water with less minerals.
Two canisters are available, the Model 80 and Model 80LC, optimized for
different water types. Contact your HVAC dealer for canister selection.
NOTE: Amperage, voltage and plumbing changes should be made by a heating
and air conditioning contractor.
OPERATING MODES
When the humidifier is powered and turned on, the “On/Off” light is illuminated
green.
When the canister is being filled or replenished with water, the “Fill” light
illuminates green.
When the canister is being drained, the “Drain” light illuminates green.
During initial start up with a new canister, the humidifier may run through a
series of fill/drain cycles until the conductivity of the water is in a range that
allows normal operation. During this time, the “Steam” light illuminates green.
If the humidifier cannot produce steam at the rated level after 168 hours of
operation, the “Steam” light illuminates yellow. The humidifier continues to
operate in this state until the rated output is reached.
The conductivity of naturally soft water, hard water, and softened water
changes as the water heats up, and the internal controller adjusts the water
level to maintain a nominal current between the electrodes. Over the life of
the canister, minerals that build up on the electrodes will reduce their effective
surface area and affect the resistance between them. The operating water level
will increase with use until it reaches the high water level probe. At that point,
the “Service” light will flash red indicating that the canister should be replaced.
The humidifier will continue to operate but with reduced output.
When the humidifier begins a drain cycle, the fill valve opens to introduce cold
water into the canister. This is done to prevent hot water from entering the
drain. The drain valve remains open for 4 minutes to allow all water to drain
from the canister.
Any time power is disconnected or the humidifier is turned off, the internal
timer for start-up and drain cycles is reset.
If the humidifier has operated 168 hours without a drain cycle, the drain valve
will open and drain the canister. Normal operation will continue.
If the humidifier is operating and a power failure occurs, once power is restored,
the “On/Off” light will flash green for one minute, then the humidifier will turn on.
If the humidifier has excessive drain cycles or cannot reach desired humidity,
contact your heating and air conditioning dealer for service.
END OF SEASON/PERIOD OF INACTIVITY SHUT-DOWN
If the humidifier does not receive a call to operate in 72 hours, the humidifier
controller drains the canister, and the drain valve will remain open for 30
minutes. The drain light will remain on until there is a humidity call or 24 hours
have elapsed. The humidifier will resume normal operation when a call for
humidity is made.
English 76 English

DISPLAY PANEL
TABLE 1 – DISPLAY PANEL
Indicator Light Function
Off Humidifier is turned OFF or not receiving power.
Solid
Green Humidifier is turned ON.
Flashing
Green
Humidifier is preparing to turn ON. Occurs if power is disconnected,
then restored with switch ON. Flashes for 1 minute.
Solid
Green
Normal operation. Fill valve is energized allowing water to flow into
canister via fill cup. (Does not illuminate when tempering water
during drain cycle.)
Flashing
Green
Fill and drain valves are pulsing to dislodge mineral build-up in
canister. Flashes 10 times in 4 seconds.
Solid Red
Fault mode. Indicates canister needs water but cannot fill. Humidifier
shuts down. Occurs if high water probe does not detect water
after fill valve is energized for 40 minutes. Call your heating and air
conditioning dealer for service.
Solid
Green
Normal operation. Humidistat is calling for steam and humidifier is
operating.
Solid
Yellow
Normal operation. Humidifier is operating but is not delivering
steam at rated capacity. Occurs if humidifier has operated for 168
hours at less than rated capacity due to low water conductivity. Light
will turn green once water conductivity increases and humidifier is
delivering rated capacity. If yellow light persists, consult your heating
and air conditioning dealer for canister options.
Flashing
Green
Humidifier is preparing to drain. (Fill valve is open tempering water
in canister.) Occurs when humidifier is turned OFF, at end of season
drain (72 hours with no operation) and during forced drain down
(168 hours of operation with no drain activity.)
Fill and drain valves are pulsing to dislodge mineral build-up in
canister. Flashes 10 times in 4 seconds.
Solid
Green
Drain valve is energized and open, draining canister. Valve remains
energized for 4 minutes.
Indicates end of season shut-down. Occurs if humidifier does not
receive call for humidity in 72 hours. Light remains on for 24 hours.
Humidifier will turn on with the next call for humidity.
Flashing
Red
Canister has reached the end of its life and needs to be replaced.
Occurs after humidifier has operated for at least 168 hours and for
an additional 24 hours at a current level below 75% of the maximum
operating current. Humidifier continues to operate, but at reduced
capacity.
Solid Red
Operational problem with humidifier. Humidifier shuts down. Occurs
when unit detects over-current which can be caused by failure to
drain or other system failures. Call your heating and air conditioning
dealer for service.
OPERATING INSTRUCTIONS – MODEL 62 AUTOMATIC
DIGITAL HUMIDIFIER CONTROL
The Model 62 Automatic Digital Humidifier Control (ADHC) offers 2 modes
of operation, Automatic or Manual. An explanation of both modes follows.
(SeeFIGURE 2 on page 10 for Automatic Mode. See FIGURE 3 on page 12 for
Manual Mode.)
When in the Automatic Mode, this system offers the following benefits:
• You will receive the optimum amount of humidity so that your home
and its furnishings are protected from the damaging effects of excess
condensation or low humidity during the heating season. The ADHC
automatically adjusts your home’s humidity based on the outdoor
temperature, increasing the time maximum comfort is maintained.
• Simple operation with few adjustments. In the Automatic Mode, the ADHC
eliminates the need to manually adjust the control when outdoor temperature
changes. It also eliminates the need to turn the dial setting to “OFF” during
the summer season.
MODEL 62 AUTOMATIC DIGITAL HUMIDIFIER CONTROL INDICATOR LIGHTS
Call Dealer for Service: The red light indicates that the control is not operating
normally and that service is required.
Humidifier ON: The green light indicates that the control is operating normally
and sending a call for humidity to the humidifier.
BLOWER ACTIVATION
The Blower Activation switch is set to the “ON” position to allow the humidifier
control to activate the HVAC fan for maximum humidification.
If the HVAC system has been idle for 1 hour, the humidifier control will activate
the HVAC system fan to sample the air for 3 minutes. If the RH is lower than
the set point, the humidifier control will activate the humidifier and keep the
fan running. The humidifier will continue to operate for 2 hours or until the
humidification set point is reached.
If the RH set point has not been reached by the end of a call for heat, the
control will continue to operate the humidifier and the HVAC fan until the
humidification set point is reached or 2 hours have elapsed.
When the Blower Activation switch is in the “OFF“ position, the humidifier
control will only operate the humidifier if humidity is required and the HVAC
system fan is operating or the HVAC system is producing heat.
NOTE: If used in conjunction with an Aprilaire 8570 Communicating
Thermostat, and the Blower Activation feature is desired, DO NOT wire the A B
communication terminals.
English 98 English

AUTOMATIC MODE
Your Aprilaire ADHC must be installed in the cold air return duct. During the
first heating season, your humidifier control needs to be set initially to match
your home’s condition. Please follow these steps when adjusting your control
(refer to FIGURE 2).
1. Turn the dial setting knob to “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 home’s
requirements. Refer to TABLE 2 – ADHC OPERATION GUIDE.
2. During the coldest portion of the first heating season, minor adjustments
may be necessary. This is dependent upon your home’s construction. Refer
to TABLE 2 – ADHC OPERATION GUIDE.
The humidity in your home will now 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 you temporarily move the knob to
“OFF” when performing annual maintenance of your Aprilaire humidifier.
Your humidifier is a precision system that will accurately maintain the humidity
in your home. For every 2°F change in outdoor temperature, the Model 62
Automatic Digital Humidifier Control will automatically adjust the indoor
humidity by 1%.
The Model 62 Automatic Digital Humidifier Control will accurately control the
humidity in your home to a maximum of 45%.
The humidity values in TABLE 3 are targets based on outdoor temperature and
the Digital Humidifier Control setting. The actual humidity may vary due to
conditions in the home (cooking, showering, etc.).
TABLE 2 – ADHC OPERATION GUIDE
Condition Solution
Condensation on windows. Reduce the setting on the control dial by 1 increment.
Lack of humidity. Increase the setting on the control dial by 1 increment.
Humidifier does not turn on.
Make certain HVAC blower is operating. Turn dial to
“Test/Reset.” If unit still does not operate, consult
a heating contractor. Display will flash software
revision level e.g. “r1,” if the control knob is left in
test/reset for longer than 1 minute.
Humidifier will not shut off.
Turn control dial to “Off.” If unit continues to produce
steam (steam light ON), disconnect main power
to turn off the humidifier and consult a heating
contractor.
Test mode.
Make certain HVAC blower is operating. System
operation is checked by setting the knob to “Test/
Reset.” Humidifier will operate for 1 minute.
Red “Call Dealer for Service”
light flashes (FIGURE 2).
Note the error code on the display (E1, E2, E3 or E4)
and call your heating and air conditioning dealer for
service.
TABLE 3 – % RELATIVE HUMIDITY GUIDE
Outdoor Temperature (°F)
-10°F 0°F 10°F 20°F 30°F 40°F
Dial Setting
110% 10% 10% 15% 20% 25%
Relative Humidity (%)
210% 10% 15% 20% 25% 30%
310% 15% 20% 25% 30% 35%
415% 20% 25% 30% 35% 40%
520% 25% 30% 35% 40% 45%
625% 30% 35% 40% 45% 45%
730% 35% 40% 45% 45% 45%
90-1235B
FIGURE 2 – AUTOMATIC MODE
English 1110 English

MANUAL MODE
When the humidistat is in Manual Mode (see FIGURE 3 – internal switch in
the “MAN” position and “M” in the display), it is important to anticipate a
drop in outdoor temperature and reduce the setting accordingly to avoid
excess condensation. For example, with an outdoor temperature of 20°F, the
recommended setting will be 35%. If the temperature is expected to fall to 0°F
that evening, reduce the setting to 25% several hours prior to the temperature
change.
See TABLE 4 for the recommended settings. These settings represent a
compromise between humidity levels within the range of comfort and
protection from window condensation. For example, a 50% indoor humidity
in wintertime may be ideal for comfort, but would result in damaging
condensation. Thus, observing recommended humidity levels on the humidifier
control is important. Condensation on the inside surface of windows in the form
of fogging or frost is indicative of over-humidification. This same condensation
can occur in other areas of the home, resulting in damage.
TABLE 4 – OUTDOOR TEMPERATURE AND RECOMMENDED INDOOR RH SETTING
Outdoor Temperature Recommended Indoor RH Setting
+40°F 45%
+30°F 40%
+20°F 35%
+10°F 30%
0°F 25%
-10°F 20%
-20°F 15%
TEST/RESET
The “Test/Reset” setting allows the humidifier operation to be checked even if
there is no call for humidity. See “Check the Humidifier Operation.”
CHECK THE HUMIDIFIER OPERATION
DIGITAL HUMIDIFIER CONTROL
Set the knob to “Test/Reset,” make sure that the water saddle valve is open and
that the humidifier is on. The HVAC fan must be running for the humidifier to
function. The humidifier will only operate for 1 minute in test mode. Reduce the
humidifier control setting to the recommended inside humidity, depending on
the outside temperature. DO NOT LEAVE IN TEST MODE AS HUMIDIFIER WILL
NOT OPERATE.
90-1236B
FIGURE 3 – MANUAL MODE
English 1312 English

FIGURE 5 – LCD DISPLAY
BLINKING ON + *:TEMP LIMITS EXCEEDED.
SEE OPERATING LIMITS, PAGE 16.
SOLID ON:
CONTROL ON
BLINKING ON:
HUMIDIFYING
NUMBERS SHOW
CURRENT ROOM
HUMIDITY OR
HUMIDITY SETTING SET IS DISPLAYED
WHEN OR
IS PRESSED. THE
VALUE DISPLAYED
IS THE RELATIVE
HUMIDITY SETTING.
OFF: CONTROL OFF
OPERATING INSTRUCTIONS –
MODEL 65 MANUAL DIGITAL HUMIDISTAT
Apply the RH setting label to the front cover if you want a guideline for setting
the control according to outdoor temperature. Since all houses are different, you
will need to determine exactly where to set the control so that you have enough
humidity to meet your needs, but not so much as to cause excess condensation
on windows or other cold surfaces.
CAUTION
Do not adjust humidity set-point above recommended level or to
recommended level if condensation occurs on inside surface of windows
or on other surfaces. Excess condensation can cause damage to structure
or furnishings. Excess moisture can allow the possibility for mold growth
to occur.
When the control is first powered up, it will display “30%,” which is the default
setting.
FIGURE 4 – CONTROL DISPLAY AND USER BUTTONS
LCD
DISPLAY
MODE BUTTONS – USE TO
TURN CONTROL ON/OFF.
BUTTONS –
USE TO VIEW AND
ADJUST RELATIVE
HUMIDITY SETTING.
RH SETTING LABEL
90-1670
TURNING CONTROL ON & OFF
Begin by pressing the “ON” button. “ON” will appear on the display. This means
the control is on, but it does not necessarily mean the humidifier is running. In
order for the control to turn on your humidifier, several conditions must be met:
1. The control and humidifier must be powered,
2. The RH level in the conditioned space must be below the set point, and
3. Your furnace or furnace blower must be running.
When these conditions are met and the humidifier is operating, “ON” will blink
in the control display.
NOTE: If you have an Aprilaire Model 800 Steam Humidifier and a Model 850
Fan Pack, they will operate independently of any HVAC (Heating, Ventilating
and Air Conditioning) equipment.
To disable the humidifier, press the “OFF” button. The control will remain on and
display “OFF” plus the actual RH but will not allow the humidifier to operate.
The control must be ON in order to adjust the RH setting.
SETTING THE DESIRED RH LEVEL
Use the and buttons to display and raise or lower the RH setting. When
pressing the and buttons, “SET” and the RH setting will be displayed.
Each press of the buttons will change the setting by 1% RH. If a button is
pressed and held, the setting will change 1% RH every 1/2 second. “SET” will
disappear and the display will once again show the actual RH 5 seconds after
the buttons are pressed.
English 1514 English

TABLE 5 – OUTDOOR TEMPERATURE AND RECOMMENDED INDOOR RH SETTING
Outdoor Temperature Recommended Indoor RH Setting
+40°F 45%
+30°F 40%
+20°F 35%
+10°F 30%
0°F 25%
-10°F 20%
-20°F 15%
OPERATING LIMITS
If the temperature in the space to be conditioned drops below 40°F or rises
above 99°F, the control will not allow the humidifier to operate. Under these
conditions, the display will blink “ON” and “*.” Once the temperature is in the
normal operating range, the control will once again allow the humidifier to
operate and the blinking “ON” and “*” will no longer be displayed.
ADJUSTING THE RH DISPLAY OFFSET
If you have another device that displays RH in your home, it may not match the
Model 65 control display due to placement or a difference in calibration. If you
want the devices to match, the RH displayed by the Model 65 control can be
adjusted higher or lower by up to five percentage points. Allow the control to
acclimate to the space for 48 hours before adjusting the offset.
The control must be on in order to adjust the offset. Press and hold the “OFF”
button for 5 seconds or until the display shows a value between -5% and +5%.
Use the and buttons to adjust the offset. The control will revert back to
the normal display mode after 5 seconds.
OPERATING INSTRUCTIONS – MODEL 63 AUTOMATIC
DIGITAL MODULATING CONTROL
The Aprilaire® Model 63 Automatic Digital Modulating
Control (ADMC) offers precise control of the humidity in
your home by providing a variable output based on the
difference between the set point and the sensed humidity.
The Automatic Digital Modulating Control offers 2 modes
of operation, Automatic or Manual. An explanation of both
modes follows. When in Automatic Mode, this system
offers the following benefits:
• You will receive the optimum amount of humidity
so that your home and its furnishings are protected from the damaging
effects of excess condensation or low humidity during the heating season.
The ADMC automatically adjusts your home’s humidity based on the outdoor
temperature, increasing the time maximum comfort is maintained.
• Simple operation with few adjustments. In the Automatic Mode, the ADMC
eliminates the need to manually adjust the control when outdoor temperature
changes.
AUTOMATIC DIGITAL MODULATING CONTROL INTERFACE
Symbols on Display
Humidification ON
Low, Medium, High demand.
Percentage of humidity
or °C: Celsius scale
°F: Fahrenheit scale
Menu setup Lock
Programming mode
(Technician setting)
Alarm status
English 1716 English

BLOWER ACTIVATION
The Blower Activation feature provided with the Model 63 ADMC turns the
HVAC system fan on when there is a call for humidity.
AUTOMATIC MODE
During the first heating season, your ADMC needs to be set to match your
home’s condition. The ADMC default set point is 40% RH. Follow these steps
when adjusting your control.
1. For the first 24 to 48 hours of operation, it may be necessary to adjust the
set point for more or less humidity, depending on your personal comfort
and home’s requirements. Refer to TABLE 6 – ADMC OPERATION GUIDE.
2. During the coldest portion of the first heating season, minor adjustments
may be necessary. This is dependent on your home’s construction. Refer to
TABLE 6 – ADMC OPERATION GUIDE.
TABLE 6 – ADMC OPERATION GUIDE
Condensation on
windows. Reduce the setting on the control by 5%.
Lack of humidity. Increase the setting on the control by 5%.
Humidifier does not
turn on.
Check that set point is higher than sensed humidity.
Make certain HVAC blower is operating and humidifier is
ON. If humidifier still does not operate consult a heating
contractor.
Humidifier won’t
shut off.
Turn ADMC OFF. If humidifier continues to produce steam
(humidifier steam light ON), disconnect main power to turn
off the humidifier and consult a heating contractor.
“OFF,” “– – –“ and
alarm symbol are
displayed.
The humidity sensor is not connected or is short circuited.
Consult a heating contractor.
“– – –“ is displayed. The temperature sensor is not connected or is short
circuited. Consult a heating contractor.
The humidity in your home will
now be accurately controlled
to meet your needs and should
not need further adjustment
during future heating seasons.
The Aprilaire ADMC measures
outdoor temperature and
automatically adjusts the set
point to prevent condensation
and damage. TABLE 7 shows
the maximum humidistat set
point the ADMC will allow for
various outdoor temperatures.
MANUAL MODE
If an outdoor temperature
sensor cannot be installed or the
application requires a specific
RH set point, the ADMC can be
configured to Manual Mode. In
Manual Mode, the humidifier
and control will maintain a
constant RH, regardless of
outdoor temperature.
It is important to anticipate a
drop in outdoor temperature
and reduce the setting
accordingly to avoid excess
condensation. See TABLE 8
for the recommended settings.
These settings represent a compromise between humidity levels within the
range of comfort and protection from window condensation. For example, a
50% indoor humidity in wintertime may be ideal for comfort, but would result
in damaging condensation. Thus, observing recommended humidity levels
on the humidifier control is important. Condensation on the inside surface of
windows in the form of fogging or frost is indicative of over-humidification. This
same condensation can occur in other areas of the home, resulting in damage.
TABLE 7 – ADMC MAXIMUM SET POINT FOR
OUTDOOR TEMPERATURE
Outdoor Temperature
°F (°C)
Maximum Setpoint
(%RH)
20 (-7) 35%
10 (-12) 30%
0 (-18) 25%
-10 (-23) 20%
-20 (-29) 15%
TABLE 8 – OUTDOOR TEMPERATURE AND
RECOMMENDED INDOOR RH SETTING
Outdoor
Temperature
Recommended Indoor
RH Setting
+40°F 45%
+30°F 40%
+20°F 35%
+10°F 30%
0°F 25%
-10°F 20%
-20°F 15%
English 1918 English