Steffes 3100 Series User manual

V17
"Manufactured in North America"
U.S. Pat. #5201024, #5086493
Can. Pat. #2059158, #2060881
Models: 3120, 4120,
4130, & 4140
Applicable to Software Version 2.00-2.19
OW ER'S A D
I STALLER'S MA UAL
for
COMFORT PLUS
Forced Air Heating Systems
Equipped with Variable Speed
4100
Series
3100
Series
This manual applies to heating
systems built after 01 01 2011.

wThe equipment described herein is intended for installation by a qualified
technician in compliance with applicable local, state, and national codes and
requirements.
wTo insure proper installation and operation of this product, completely read all
instructions prior to attempting to assemble, install, operate, maintain or repair
this product. Upon unpacking of the system, inspect all parts for damage prior
to installation and start-up.
wThis manual should be retained by the owner upon completion of the installa-
tion and made available to service personnel as required.
wDisclaimer In compiling this manual, Steffes Corporation has used its best
judgement based upon information available, but disclaims any responsibility
or liability for any errors or miscalculations contained herein, or any revisions
hereof, or which result, in whole or in part, from the use of this manual or any
revisions hereof.
Steffes disclaims any responsibility or liability for mold/mildew growth and/or
any damages caused by either which occur after the heating system is in-
stalled. We strongly recommend that the user follow the moisture, mold and
mildew prevention guidelines of the Environmental Protection Agency (EPA),
available at http //www.epa.gov. If you are unable to find information and have
concerns, contact Steffes Corporation.
IMPORTANT
For Customer Use
Please record your model and serial number below. This number is found on the identification label
located on the lower front of the 3100 series base and on the lower left side of the 4100 series base.
Retain this information for future reference.
Model No. ________________________________________________________________________
Serial No. ________________________________________________________________________
RECOGNIZE THESE SYMBOLS AS SAFETY PRECAUTIONS
It is important, both for your personal safety and to avoid possible damage
to the equipment and your property, that you observe the safety instruc-
tions given following these symbols.

SAFETY PRECAUTIONS
1. Install all ceramic brick and completely assemble the
heating system before energizing the system to avoid
damage to the heating system.
2. DO NOT se or store materials that may prod ce
explosive or flammable gases near this heating system.
3. Maintain all placement and clearance req irements as
specified in this man al to ens re proper operation and
safety.
4. Keep the top of the heating system free of debris and
other objects.
5. Disconnect power to all circ its before servicing. This
heating system may be connected to more than one
branch circ it.
6. Installation of and/or service to this heating system
sho ld be performed by a q alified technician in compli-
ance with information contained herein and with national,
state, and local codes and req irements.
7. A repeated message of CORE FAIL indicates a need
for service by a q alified technician.
BUILT-IN SAFETY DEVICES
The Comfort Pl s heating system incorporates safety devices to ens re normal operating temperat res are main-
tained. The chart below describes these safety devices.
DEVICE NAME FUNCTION LOCATION
ON SYSTEM
Core Charging High
Limit Switches
(A to Reset)
These limit switches monitor brick core charging and
interr pt power to the heating elements if the normal
operating temperat re is exceeded.
This limit switch monitors the discharge air temperat re
and interr pts power to the core blower(s) if the normal
operating temperat re is exceeded:
3100 Series = 130oF (nominal)
4100 Series = 170oF (nominal)
Core Blower
Limit Switch
(A to Reset)
This limit switch monitors the discharge air temperat re
and interr pts power to both the s pply air blower and the
core blower(s) if the normal operating temperat re is
exceeded:
3100 Series = 160oF (nominal) A to Reset
4100 Series = 190oF (nominal) Man al Reset
S pply Air Blower
Limit Switch
Base Temperat re
Limit Switch
(A to Reset)
This limit switch monitors the temperat re in the base of the
Comfort Pl s and interr pts power to the core blower(s) if
the normal operating temperat re is exceeded.
In the base of the
system near the core
blower(s).
In the limit bar panel
on the left side of the
brick storage cavity.
3100: In the discharge
air s pply o tlet.
4100: On the dis-
charge air
s pply blower.
3100: In the discharge
air s pply o tlet.
4100: On the dis-
charge air
s pply blower.
Comfort Plus Safety Information
WARNING
Hazardous Voltage Risk of
electric shock. Can cause injury
or death. This heater may be
connected to more than one
branch circuit. Disconnect
power to all circuits before
installing or servicing. Installa-
tion of and/or service to this
equipment MUST be performed
by a qualified technician.
Risk of fire. Can cause injury or
death. Violation of the clear-
ance requirements can cause
improper operation of the
equipment. Maintain the place-
ment and clearance require-
ments specified.

Operation
General Operation ........................................................................................................................................................................ 1.01
System Use D ring Constr ction Phase ...................................................................................................................................... 1.01
System Start-Up ........................................................................................................................................................................... 1.01
T rning System "OFF" and "ON" ............................................................................................................................................... 1.01
Control Panel ............................................................................................................................................................................... 1.02
Operating Stat s .......................................................................................................................................................................... 1.02
Room Temperat re Control .......................................................................................................................................................... 1.03
Brick Core Charge Control ........................................................................................................................................................... 1.03
Charge Control Override .............................................................................................................................................................. 1.03
Maintenance and Cleaning .......................................................................................................................................................... 1.03
Optional Accessories
Single Electrical Feed Kit ............................................................................................................................................................. 2.01
Comfort Pl s Stand - 4100 Series ................................................................................................................................................. 2.01
Down Flow Kit ............................................................................................................................................................................. 2.01
Ret rn Air Plen m - 4100 Series ................................................................................................................................................... 2.01
Installation
Shipping and Packaging .............................................................................................................................................................. 3.01
Placement and Clearance Req irements ................................................................................................................................3.02-3.03
Initial Set- p ..........................................................................................................................................................................3.03-3.04
Brick Loading ............................................................................................................................................................................... 3.04
Heating Element and Air Channel Installation ............................................................................................................................. 3.05
Brick Core Temperat re Sensor Installation - 4100 Series Only ................................................................................................... 3.06
D cting ................................................................................................................................................................................. 3.06-3.07
Air Conditioner/Heat P mp Interface ........................................................................................................................................... 3.08
Line Voltage Electrical Connections .....................................................................................................................................3.08-3.09
Low Voltage Electrical Connections
Peak Control .................................................................................................................................................................. 3.09-3.10
O tdoor Temperat re Sensor ............................................................................................................................................... 3.10
Room Thermostat .......................................................................................................................................................... 3.11-3.12
A xiliary Load Control ................................................................................................................................................................. 3.12
H midifier/Electronic Filter Installation ........................................................................................................................................ 3.12
Config ration Men .............................................................................................................................................................3.13-3.14
Installer's Final Check-O t Proced re .......................................................................................................................................... 3.15
Appen ix
Specifications .............................................................................................................................................................................. A.01
Disassembling the 4100 Series Comfort Pl s System .................................................................................................................. A.02
Parts Diagram - 3100 Series ......................................................................................................................................................... A.03
Parts List - 3100 Series ....................................................................................................................................................... A.04-A.05
Parts Diagram - 4100 Series ......................................................................................................................................................... A.06
Parts List - 4100 Series ....................................................................................................................................................... A.07-A.08
Internal System Wiring Diagrams - Line Voltage ............................................................................................................... A.09-A.12
Internal System Wiring Diagram - Low Voltage .......................................................................................................................... A.13
Help Men .................................................................................................................................................................................. A.14
Error Codes ........................................................................................................................................................................ A.14-A.15
Glossary ...................................................................................................................................................................................... A.16
Warranty
Table of Contents
TC
Table of Contents Comfort Plus

GENERAL OPERATION
The Steffes Comfort Pl s heating system stores off-peak electricity in the form
of heat. Off-peak electricity is available d ring times of day or night when
electricity is plentif l and the power company can s pply it at a lower cost.
Operation of the Comfort Pl s heating system is a tomatic. When off-peak
ho rs are available, the system converts electricity to heat which is then stored
in its ceramic brick core. The amo nt of heat stored in the brick core varies in
relation to o tdoor temperat re, owner preference, tility peak conditions, and
the heating req irements.
A heat call from the room thermostat energizes the blowers in the Comfort Pl s system. The variable speed core
blower(s) a tomatically adj st its speed to circ late room air thro gh the brick core. The s pply air blower then
delivers this heated air into the desired area thro gh the d ct system to maintain a constant, comfortable room
temperat re.
The versatility of this system allows it to fit many applications. The Comfort Pl s is designed for se as either the
sole heating so rce (stand alone f rnace) or as a s pplement to d cted heating systems s ch as heat p mps.
SYSTEM USE DURING CONSTRUCTION PHASE
Like most heating eq ipment man fact rers, Steffes strongly recommends that Constr ction Heating Units be
sed instead of the permanent heating system d ring the constr ction phase of a new home. Use of the permanent
heating system d ring this phase may contaminate the d ct system and/or internal areas of the heating system.
This may ca se poor indoor air q ality iss es, systems reliability problems, and/or improper system operation once
the home is completed.
SYSTEM START-UP
On start- p of the Comfort Pl s system, odors relating to first time operation of the heating components may be
experienced. Also, if not sed for an extended period of time, d st may acc m late in the system. Allow the
Comfort Pl s heating system to charge to its maxim m brick core charge level to expel odors in a timely manner.
As with most heating systems, air borne particles and odors in the room may be drawn into the Comfort Pl s and
oxidized. Odors can be am lified; thus, it is not recommended to o erate the system if odors such as those
from aints, varnishes, or chemicals are resent in the air. Air borne particles, which have been oxidized, are
expelled back into the room and may acc m late on air vents or other s rfaces. Over time, these particles may
appear as a black resid e, commonly referred to as soot. High concentrations of air borne particles from aerosols,
d st, candles, incense, pet hair, smoke, or cooking can contrib te to poor indoor air q ality and accelerate the
sooting process.
D ring operation, the Comfort Pl s heating system may prod ce minor expansion noises. These noises are the
res lt of the internal components reacting to temperat re changes.
TURNING SYSTEM "OFF" AND "ON"
The Comfort Pl s element (charging) circ its may be t rned OFF by switching ALL of the 60 AMP breakers
located on the front of the electrical panel to the DOWN position. To t rn the element circ its ON, switch ALL
of the 60 AMP breakers to the UP position.
The 15 AMP breaker MUST remain ON to o erate controls in the system if:
wusing the Comfort Plus in conjunction with a heat um or air conditioner.
wusing the Comfort Plus to control other loads.
wusing the o tional Steffes Time Clock Module.
Comfort Plus Operation n 1.01
Operation
Operation
1

CONTROL PANEL
Operation of the Comfort Pl s heating system is a tomatic. Operational f nction
settings are stored in a microprocessor on the processor control board. These settings
are modified, if necessary, thro gh the Config ration Men as described on Pages
3.13-3.14. In most applications, the system is configured u on installation and no
f rther changes are req ired.
Four-Digit LED Dis lay
The fo r digit LED displays specific operating information. D ring the config ration
process, the config ration n mber and the val es set in these config rations are
displayed for viewing and adj sting p rposes.
AM and PM Indicator Lights
The AM and PM indicator lights are only tilized if the Steffes Time Clock Mod le is being installed and sing 12
ho r time display. With this mod le installed, the system displays time on AM/PM intervals. The light flashes next
to the active designator/symbol. The system can be config red to display military time, in which case, both the AM
and PM lights ill minate.
Mode (Edit) Button
Used to access men s on the system (i.e. Help Men or Config ration Men )
and to allow modifying of config ration settings.
U and Down Arrow Buttons
Used to scroll p or down when viewing or modifying.
operating f nctions.
Interface Port
Allows technician external access for advanced operating modes, pdating software, and tro bleshooting.
OPERATING STATUS
The fo r digit LED will display vario s operating information as described below. Press and release the p arrow
to view this data.
O erating Mode - Indicates the c rrent operating mode of the Comfort Pl s system.
C = Off-Peak (Charge) Time
P = On-Peak (Control) Time
A = Anticipated Peak Time
Outdoor Tem erature -O, followed by a n mber, indicates c rrent o tdoor temperat re.
Heat Call Status - Indicates the c rrent heat call stat s being received from the room
thermostat. Refer to Low Voltage Electrical Connections - Room Thermostat for more
information.
Brick Core Charge Level - CL (charge level) followed by a n mber, indicates the
c rrent percentage of heat stored in the brick core. CL:_ represents a core temperat re
lower than the minim m core temperat re and CL: F represents a f ll core charge level.
Targeted Brick Core Charge Level - tL (target level) followed by a n mber, indicates
the c rrent percentage of brick core charge being targeted by the Comfort Pl s. A display of
tL:_ indicates that the system will not maintain any heat in the brick core and tL: F
indicates a f ll core charge target level.
Operation n 1.02 Comfort Plus
M
ñò
Operation
A bar illuminates on the lower ortion of
the dis lay's second digit whenever the
heating elements are energized.
CONTROL PANEL
FIGURE 1
M
M
A
M
P
IMPORTANT
Editing configuration
information may alter
the performance and
operation of the system.

Comfort Plus Operation n 1.03
Operation
ROOM TEMPERATURE CONTROL
The room temperat re set point is adj sted at the wall thermostat. If room temperat re drops below the thermo-
stat set point, the thermostat initiates a heat call and energizes the blowers in the Comfort Pl s heating system. The
variable speed core blower(s) a tomatically adj st speed in relation to brick core temperat re and d ct temperat re
to circ late room air thro gh the brick core. The s pply air blower then delivers the heated air into the living area
thro gh the d ct system to satisfy heating req irements. When the thermostat senses a demand greater than the
o tp t, another stage of heating is initiated.
When sed to s pplement heat p mp systems, the Comfort Pl s replaces the resistance strip heat, which is typi-
cally req ired as a s pplement or back- p to the heat p mp system. A d ct sensor monitors the discharge air
temperat re. If the demand for heat is at a point where the heat p mp alone cannot maintain the desired d ct
temperat re, stored heat is sed to s pplement the heat p mp and satisfy the heating req irements.
BRICK CORE CHARGE CONTROL
The amo nt of heat stored in the brick core of the Comfort Pl s system is reg lated a tomatically in relation to
o tdoor temperat re and the heating req irements. The o tdoor sensor, s pplied with the system, monitors
o tdoor temperat re and provides this information to the Comfort Pl s. As the o tdoor temperat re decreases,
heating req irements increase and the system stores more heat accordingly.
CHARGE CONTROL OVERRIDE
The Comfort Pl s is eq ipped with a charge control override feat re that allows the ser to force the system to
target a f ll core charge level. This override can be initiated or cancelled at any time. If an override is initiated,
the system targets a f ll core charge level d ring the next off-peak period. It contin es to charge d ring off-peak
ho rs ntil the system achieves f ll (maxim m) core charge or ntil the override is cancelled. Once f ll charge is
achieved or the override is cancelled, the system charges according to the standard config ration.
Initiating the Override Feature
Ste 1 Press and hold the M, the p arrow, and the down arrow b ttons at the same time.
Ste 2 The faceplate will flash FULL and ON. Contin e to hold all three b ttons ntil ON displays
contin o sly.
Ste 3 Release the b ttons. The override is now enabled. The faceplate will ret rn to displaying its standard
operating mode.
Manual Cancellation of the Override Feature
Ste 1 Press and hold the M, the p arrow, and the down arrow b ttons at the same time.
Ste 2 The faceplate will flash FULL and OFF. Contin e to hold all three b ttons ntil OFF displays
contin o sly.
Ste 3 Release the b ttons. The override is now cancelled. The faceplate will ret rn to displaying its standard
operating mode.
This feature will not turn elements on during a eak eriod.
This feature will cancel if ower is interru ted.
MAINTENANCE AND CLEANING
The Comfort Pl s heating system is easily maintained. The air filter in the ret rn air d ct of the system sho ld be
replaced on a reg lar basis to ens re proper operation and to maintain overall efficiencies. No additional ro tine
maintenance is req ired.
If tilizing a heat p mp or air conditioning system with the Comfort Pl s, the indoor coil of the device sho ld be
cleaned periodically as dirt acc m lation may red ce system efficiency. It is important to follow the
man fact rers maintenance and cleaning recommendations for these devices.

Optional Accessories n 2.01 Comfort Plus
Optional Accessories
2
Accessories
SINGLE ELECTRICAL FEED KIT
The Steffes Comfort Pl s systems have b ilt-in circ it
breakers. They are factory config red to be field con-
nected to m ltiple line voltage circ its. If single feed to
the element and blowers/control circ its is desired, the
single feed kit is available to allow the system to be
powered with a one, larger line voltage circ it.
COMFORT PLUS STAND - 4100 SERIES
Some applications (s ch as garages) may req ire that the heating appliance be
elevated in order to meet b ilding codes. The Steffes Comfort Pl s stand elevates
the 4100 system 18". This stand is shipped as a kit and req ires field assembly.
Model Part #
3120 1301574
4120 1301572
4130/4140 1301570
RETURN AIR PLENUM - 4100 SERIESDOWN FLOW KIT
Order Item #1301578 Order Item #1301550
Order Item #1301585
Stand

Duct
Opening
(connects
to unit)
Filter Tray
(Fits 20" x 25" x 2" filters, one included)
Heating/Cooling A-Coil Tray
Inner Dimensions: 26"W x 22"D x 31" H
Front Access: 25
1
2
"W x 22"D x 30"H
52 5/16”
28 3/16”
22 3/16”
26 1/16”
9.263
+ Set Height
of Leveling Legs.

Comfort Plus Installation n 3.01
Installation
3
SHIPPING AND PACKAGING
The Comfort Pl s system sho ld always be transported in an pright position to avoid damage to internal compo-
nents and ins lation materials. The information below describes the items shipped with each system.
CERAMIC BRICK
ELEMENT SCREW KIT
(shipped
inside the
electrical
compartment)
5
(shipped inside the
electrical compartment)
OUTDOOR TEMPERATURE SENSOR
2
3
1INFORMATION PACKAGE
(includes Owner's Manual and
Warranty Registration Card)
(adhered to outer side of shippin box)
MODEL ELEMENTS
3120 8
4120 8
4130 12
4140 16
(shipped inside the base of
the Comfort Plus)
HEATING ELEMENTS
4
SUPPLY AIR BLOWER ASSEMBLY
(4100 SERIES)
Packaging Dimensions 26 x 24.5 x 20.5
(shipped separately)
6
MODEL FULL BRICK 1/2 BRICK
3120 18 Boxes 0 Boxes
4120 26 Boxes 1 Box
4130 37 Boxes 2 Boxes
4140 49 Boxes 2 Boxes
RETURN AIR PLENUM ASSEMBLY
(3100 SERIES)
Packaging Dimensions 27 x 40 x 4
(banded to the 3100 Series Comfort Plus for shippin )
7
Full Brick
(shipped separately
and packa ed 4 brick
per box)
Half Brick
(shipped with brick and
packa ed in a white box
consistin of 6 half brick
and 1 full brick)
CAUTION Risk of sharp edges. Can cause personal injury. Use caution
when installing and/or servicing equipment.

16"
41 58"
67 716"
60"
10 18"
53 58"
5 38"
1"
27"
22716"
22516"
1" Top View
2618"
178"
812"16716"
Installation n 3.02 Comfort Plus
Installation
PLACEMENT AND CLEARANCE REQUIREMENTS
The physical dimensions of the Comfort Pl s, along with the
clearances req ired, MUST be taken into consideration when
choosing its location within a str ct re. (See Fig res 2 and 3
for system dimensions and clearance req irements.)
The best installation location for this system is in a space
req iring heat so some amo nt of the heating req irements can
be satisfied thro gh static dissipation from the warm o ter
panels. In sit ations where the Comfort Pl s is not installed in
an area it is intended to heat (i.e. storage closet), it is important
to acco nt for the heat lost thro gh static dissipation by making
proper adj stments when sizing the system. Standby heat
dissipation of p to 2.5kW can be experienced in normal opera-
tion. Room air sho ld be maintained at less than 85° Fahrenheit.
If ventilation is needed, it can be provided by installing a 24 x
24 opening into the area where the Comfort Pl s is located. In
addition, a 6 x 6 non-closing type register can be c t into the
ret rn air d ct of the f rnace to minimize heat b ild- p in the
room. This register m st be installed in a manner that ens res
the air drawn into the Comfort Pl s passes thro gh the filter
first (see Fig re 3A).
In addition to the physical space req irements, the weight of the Comfort Pl s m st be taken into consideration
when selecting the installation s rface. A level concrete floor is the best installation s rface on which to place the
system, b t most well s pported s rfaces are acceptable. If ns re of floor load capacity, cons lt a b ilding
contractor or architect.
S ecial requirements must be considered if lacing the system in a garage or other area where
combustible va ors may be resent. Consult local, state, and national codes and regulations to
ensure ro er installation. An 18" edestal (Order Item #1301585) is available to elevate the
4100 Series.
3100 SERIES SYSTEM REQUIREMENTS
FIGURE 2
wBack and Bottom = 0 clearance
wLeft Side = 4 inches
wRight Side = 8 inches (from comb stible material)
wTop = 8 inches (from comb stible material)
wFront = 36 inches (for ease in servicing)
wO ter Sides of System D cts (Ret rn and S pply) = 0 clearance
wBetween D cting and System = 0 clearance (top and right side)
2A 2B
CLEARANCES
2D Return
Air
Plenum
(Factory
Su lied)
2C
DIMENSIONS
Minimum clearance requirements may NOT account for
required working s ace for electrical connections.
FRONT VIEW
8" MIN CLEARANCE TO COMBUSTIBLES,
0" MIN CLEARANCE TO DUCTING
15 6060
4" MIN
CLEARANCE
M
STEFFES
A
M
M
P
36" MIN CLEARANCE (FRONT)
0" MIN
CLEARANCE
TO RETURN
AIR DUCT
TOP VIEW
O" MIN
CLEARANCE
(BACK)
Risk of fire. Can cause injury or death.
wViolation of the clearance require-
ments and/or failure to provide proper
ventilation can cause improper opera-
tion of the system. Maintain the
placement and clearance require-
ments as specified and provide venti-
lation as necessary.
wFailure to maintain room temperature
in the mechanical room of 85oF or less
may result in equipment damage.
Thermostatically controlled ventilation
should be provided if the temperature
in this area exceeds 85oF.
wMoving the system after install may
result in equipment damage. Do NOT
move system from original installed
location.
WARNING

Comfort Plus Installation n 3.03
Installation
4100 SERIES SYSTEM REQUIREMENTS
FIGURE 3
CLEARANCES
INITIAL SET-UP
Ste 1 Remove the Information Package from the
o tside of the shipping box and npackage the
Comfort Pl s heating system.
Ste 2 Remove the heating elements from inside the
base of the system.
Ste 3 Move the system into its installation location.
The Comfort Pl s is capable of fitting thro gh
a 30" doorway (minim m) witho t disassem-
bling. If necessary, the 4100 series can be
disassembled for ease in moving. To disas-
semble the 4100 Series Comfort Pl s, refer to
the disassembly instr ctions (Page A.02) for
more information.
The 3100 series can NOT be disassembled.
IMPORTANT
Risk of improper operation or equipment dam-
age. Read and follow installation instructions
carefully.
wRemove the Comfort Plus system from its
shipping pallet before installing.
wLeveling legs should be extended no more
than one inch.
wDO use and follow generally accepted safety
practices when handling insulation material.
wDO have equipment installed by a qualified
technician in compliance with all applicable
codes and regulations.
3A
FRONT VIEW
48"
2" MIN
CLEARANCE
(IN COLD AIR RETURN)
6" X 6" REGISTER
FILTER TRAY
0" REQUIRED
CLEARANCE
M
STEFFES
P
M
M
A
0" REQUIRED
CLEARANCE
6" MIN CLEARANCE
3B
TOP VIEW
36" MIN CLEARANCE
3" MIN CLEARANCE
DIMENSIONS
P
M
(4100 Series)
18" Standard
22 1
2" if 1hp
Front View
293
16
133
4± 1/4"
14±1/4 4100 Series
Top View
101
2
225
16
Electrical
Panel
263
16"
283
16"
201
4
497
16" Standard
5315
16" if 1hp
24 3
4" if 1hp
4140
68 58"
4130
57 58"
4120
46 58"
25 1
16"241
4"
Return Air Plenum
(Order Item
#1301550)
221
4"22 5/8"
Supply Air Plenum
(Factory Supplied)
4411
16"
8 3/8"
(± 1/4")
22 5/8"
M
A
M
STEFFES
wBack and Sides = 3 inches (from comb s-
tible material)
wBottom = 0 clearance
wTop = 6 inches (from comb stible material)
wFront = 36 inches (for ease in servicing)
wBetween D ct and Left Side of System =
2 inches
wBetween D ct and Right Side of System =
0 clearance
wO ter Sides of System D cts (Ret rn and
S pply) = 0 clearance
IMPORTANT:
Return air duct
MUST NOT enter
from the front or
back of the furnace.
U flow, downflow, or
straight return
ducting only.
3D
3C
Minimum clearance requirements may NOT account for required working s ace for
electrical connections.

Installation n 3.04 Comfort Plus
Installation
Ste 4 Once in place, adj st the leveling legs on the bottom of the system as necessary to prevent rocking. If
not placed properly the system may bend or twist d ring the brick loading process, making element and
brick core temperat re sensor installation diffic lt. Leveling legs sho ld be extended no more than one
(1) inch.
Ste 5 Remove the painted front panel of the electrical compartment by removing the screws along the edges.
Locate the element screw kit and the o tdoor sensor.
Ste 6 Remove the painted front panel of the brick storage cabinet by removing the sheet metal screws along
the top, bottom, and sides of the panel. Detach by p lling the bottom of the panel forward and down.
Ste 7 Locate the element wiring harnesses behind the front painted panel. Caref lly position them to avoid
damage d ring the brick loading and wiring processes.
Ste 8 4100 SERIES ONLY. Locate the brick core temperat re sensor(s) behind the front panel and discon-
nect them from their shipping position. Caref lly position the sensor(s) to avoid damage d ring brick
loading and wiring.
Models 4130 and 4140 have two brick core tem erature sensors.
Ste 9 Remove the galvanized front panel and set it aside.
Ste 10 Starting at the bottom, caref lly lift the two ins lation blankets, one at a time, and drape them over the
top of the system.
Use face mask, gloves, and long sleeved garments when handling insulation materials
in com liance with generally acce ted safety ractices.
Ste 11 Remove the front air channel by p lling o t on the bottom of the air
channel on a 3100 series or the top of the air channel on a 4100
series.
BRICK LOADING
Load the brick, one row at a time, sing a left side, right side, center pattern.
Start at the back of the brick core and work forward. Make s re the brick
are placed so the grooved side is facing p, the notch is facing forward, and
the ridges are on the left and right (see Fig re 4).
BRICK INSTALLATION TI S:
Install bricks caref lly to avoid damage to
the ins lation panels.
Remove loose brick debris to prevent
neven stacking of brick as this can red ce
heating element life and/or make installation
of the elements and the brick core tempera-
t re sensor(s) diffic lt.
Brick rows MUST line p front to back and
side to side.
Half brick makes brick loading easier by
evening o t the stacks. Use the HALF
BRICK (boxes marked) in the proper rows
and in the correct positions as indicated in
Fig re 4. The back half of the brick MUST
be installed in the back rows and the front
half (the notched brick piece) MUST be
installed in the front rows.
FRONTOFUNIT
HALF BRICK
NOTCH IN BRICK
3120: Does not contain half brick
4120: Load in row 5
4130: Load in row 4 and 8
4140: Load in row 6 and 12
BRICK LOADING
FIGURE 4
Risk of fire. Can cause
personal injury or death. DO
NOT operate the system if
damage to the insulation
panels on the inner sides of
the brick core occurs.
WARNING

Ste 1 After all brick are loaded, insert the heating elements
between the brick layers, sliding them in ntil the element
ends embed into the side c to ts of the brick cavity.
3100 Series: The threaded screw tabs on the wire
connection terminals sho ld point forward.
4100 Series: The elements MUST be installed so their
threaded screw tabs on the wire connection terminals point
forward and down. If they are installed with the screw
tabs pointing pward, element-to-wiring harness connec-
tions (Fig re 6) will be diffic lt. Be s re the elements are
slid into the brick core properly to ens re correct clearance
between the terminal connections and any s rfaces within
the system as shown in Fig re 6.
Ste 2 Install the front air channel with the air
deflectors (arrow shaped pieces) facing
inward and with the narrow ends of the
deflectors pointing p.
3100 Series: Place top portion in first.
4100 Series: Place bottom portion in
first (see Fig re 6.)
Ste 3 Lower the ins lation blankets back into
position, one at a time. Caref lly t ck
the sides of the ins lation into the edges,
corners, and aro nd the exposed por-
tions of the heating elements to ens re
maxim m efficiency.
Ste 4 Reinstall the galvanized front panel and
sec re it to the Comfort Pl s system
sing the screws that were originally removed.
3100 Series: Slide the top of this panel inside the
pper lip of the top painted panel. The bottom
sho ld rest on the o tside of the cavity and sec re
to the base with screws.
4100 Series: Slide the bottom of this panel inside
the lower lip of the brick cavity. The top rests on
the o tside of the cavity.
Ste 5 Caref lly ro te wiring harnesses and connect
them to the heating elements, sing screws
provided in the hardware package. Make connec-
tions with screw heads p and threads pointing
down. Element screws sho ld be tightened to 14
inch lbs. Refer to Element Connection (Fig re 6)
for proper positioning.
Ste 6 The painted front panel can now be installed on
3100 systems. If installing a 4100 system, the
brick core temperat re sensor(s) m st be installed
prior to p tting the painted front panel in place.
HEATING ELEMENT AND AIR CHANNEL INSTALLATION
Comfort Plus Installation n 3.0
Installation
ELEMENT INSTALLATION
FIGURE 6
3
4"
Required Clearance Between
Element Termination and Metal
Panels is 1/2" (3/4" Nominal)
Element Connection
TOP VIEW
HAZARDOUS VOLTAGE Risk of electric
shock. Can cause injury or death.
wDO NOT remove the electrical panel
cover while system is energized.
wPosition elements properly to avoid
short circuiting them against metal
surfaces.
wProtect element lead wires from front
panel screws and any field installed
screws to avoid short circuit.
WARNING
4100 SERIES AIR CHANNEL PLACEMENT
FIGURE 5
20.3"
10.4"
BRICK
CORE
SIDE VIEW
Front Air Channel
Electrical
Panel
BrickSideBottom
BackView
FrontView

Installation n 3.06 Comfort Plus
Installation
BRICK CORE TEMPERATURE SENSOR INSTALLATION -
4100 SERIES ONLY
Ste 1 Remove the screw(s) by the brick core temperat re sensor hole(s) in
the galvanized front panel.
Models 4130 and 4140 have an u er and a lower brick
core tem erature sensor.
Ste 2 Insert the brick core temperat re sensor(s) thro gh the hole(s) in the
galvanized front panel. If installing a system with two sensors, be s re
the one marked " pper" is installed in the pper opening and the one
marked "lower" is installed in the lower opening. The sensor(s) m st
pass thro gh the blanket ins lation and into the brick core. Holes have
not been predrilled thro gh the ins lation. Use the sensor(s) to aid in making a passageway by rotating
the sensor(s) side-to-side while gently p shing inward.
Ste 3 Once the brick core sensor(s) is installed, p t the screw(s) back into position in the galvanized front panel
to hold the sensor(s) in position and to provide the electrical gro nd.
Ste 4 Check the non-ins lated element terminations to make s re they do not come within 1/2" of any s rface
area on the system.
Ste 5 Re-install painted front panel, sing previo sly removed screws.
DUCTING & AIR FLOW
For air delivery, the Comfort Pl s is eq ipped with a
variable speed s pply air blower. When interfacing
with a heat p mp, the A-Coil MUST be placed on the
ret rn air side.
To maintain a room temperat re of 85oF or less in the
mechanical room, a 24" x 24" opening can be installed
in the area or a 6" x 6" non-closing register can be c t
into the ret rn air d ct. Refer to Placement and
Clearance Req irements (Page 3.02-3.03) for more
information.
3100 SERIES
The 3100 series is factory config red for a right-to-
left air flow.
Ste 1 Assemble the factory s pplied ret rn air plen m
per the assembly instr ctions.
Ste 2 Once assembled, set the plen m on the right side
of the system with the air filter and indoor coil
access covers facing forward. Line p the pre-
drilled holes on the system with the holes in the
flanges of the plen m and attach sing the screws
provided in the plen m's hardware package.
Ste 3 Insert the air filter into the filter rack.
Ste 4 Connect ret rn air d ct to top of ret rn air plen m.
Ste 5 Connect the s pply air d ct in the str ct re directly to the system's air o tlet located on the top of the
system.
Ste 6 Adj st the CFM setting at the variable speed low voltage circ it board as shown in Fig re 7.
Ste 7 The W/E j mper (Fig re 7) MUST be in the ON position or the blower will not operate with an "E" call
from the thermostat.
Risk of improper operation.
Proper installation of the
brick core temperature
sensor(s) is critical to the
operation of the Comfort
Plus heating system. Read
and follow installation
instructions carefully.
CAUTION
HAZARDOUS VOLTAGE
Risk of electric shock. Can cause injury or death.
wDo install ducting before energizing the system.
wDo NOT operate the Comfort Plus without ducting
installed to both the air inlet and outlet.
wProper duct design and air flow are critical to
achieve optimum system performance. A poorly
designed duct system and/or improper air flow can
cause system inefficiencies, air noise, and conden-
sate drain problems. In applications where poor air
flow conditions exist along with high humidity, it
may be necessary to install a secondary conden-
sate drain pan. (Order Item #1301576).
WARNING
FIGURE 7
Jumper
½ HP Variable
Speed CFM
A 1000
B 1200
C 1400
D 1600
External static pressure should not exceed .75 inches
water column.
NOTE With 2 stage Heat Pump, a Stage 1 heat call
results in 70% of selected CFM.

Comfort Plus Installation n 3.07
Installation
4100 SERIES
The 4100 series is factory config red for a left-to-right or right-
to-left airflow. In either airflow direction, the holes directly
above the air o tlet on the right side of the 4100 Series MUST
be contained in the d ct system. (See Fig re 8 for reference
to these air holes.)
If a down flow config ration is desired with the 4100 series, a
down flow kit m st be ordered from the factory (Order Item
#1301578) and the system MUST be raised a minim m of 10"
off the gro nd. An 18" pedestal is available (Order Item
#1301585) to elevate the Comfort Pl s.
Ste 1 Unbox the s pply air blower plen m assembly.
Ste 2 Remove and discard metal plate sec ring s pply air
blower to plen m assembly.
Ste 3 Locate the plen m s pport bracket shipped in the
plen m box. Attach the bracket to the s pply air side
sing the bl nt tip screws s pplied in the plen m
assembly hardware package. Refer to Fig re 8 for
proper positioning of the plen m s pport bracket.
Ste 4 Attach the s pply blower wiring harness located in
the base of the system to the blower sing the connections located
on the ends of the harness. Be s re to place any excess wiring in
the base of the system below the radiant heat shield (Fig re 8).
Ste 5 Verify that the blower is installed in the plen m with the motor
facing away from the system (Fig re 9).
Ste 6 Attach the s pply air blower plen m to the Comfort Pl s by drilling
two 1/8 holes per edge and sing the self tapping screws s pplied
in the hardware package.
Ste 7 Connect both the ret rn air and s pply air d cting systems in the
str ct re to the Comfort Pl s system. Be s re the air holes j st
above the air o tlet on the right side are contained in the d ct
system. (See Fig re 8 for reference to the location of these holes.)
If the Comfort Plus system is installed in a small enclosed area (less than 400 square
feet), a minimum of a 24"x 24" o ening must be installed into the area where the sys-
tem is located. In addition, a 6" x 6" non-closing ty e register can be cut into the
return air duct. Refer to the Placement and Clearance Requirements section (Pages
3.02-3.03) for more information.
Ste 8 Connect the s pply air d ct in the
str ct re directly to the system's air
o tlet located on the top panel.
Ste 9 Adj st the CFM setting at the vari-
able speed low voltage circ it board
as shown in Fig re 10.
Ste 10 The W/E j mper (Fig re 10) MUST
be in the ON position or the blower
will not operate with an E call from
the thermostat.
4100 SERIES
SUPPLY AIR PLENUM ATTACHMENT
FIGURE 8
When routing the harness to the supply
air blower, the harness must route to the
side of the air deflector in the bottom of
the supply air blower housing.
CAUTION
Air
Holes
Plenum Support Bracket
Radiant Heat Shield
FIGURE 10
External static pressure should not exceed .75 inches water column.
NOTE With 2 stage Heat Pump, a Stage 1 heat call results in 70% of
selected CFM.
Jumper
½ HP Variable
Speed CFM
1 HP Variable
Speed CFM
A 1000 1200
B 1200 1400
C 1400 1600
D 1600 2000
FIGURE 9

LINE VOLTAGE ELECTRICAL CONNECTIONS
In standard config ration, the Comfort Pl s is wired for connec-
tion to 240V, however, the element circ its can also be con-
nected to 208V. A 208V connection derates the charging inp t
of the system by 25%. If a system rated specifically for 208V
or 277V is req ired, contact the factory. The controls circ it in
the Comfort Pl s system MUST be connected to 240V/208V.
The 60 amp breakers located in the electrical compartment on
the Comfort Pl s feed the core charging (element) circ its. The
15 amp breaker feeds the controls and blowers circ it.
Installation
HAZARDOUS VOLTAGE Risk of electric
shock. Can cause injury or death. Do not
energize the system until installation is
complete. Equipment MUST be installed
by a qualified technician in compliance
with all applicable local, state, and
national codes and regulations.
WARNING
AIR CONDITIONER/HEAT PUMP INTERFACE
When interfacing the Comfort Pl s system with a heat p mp, the
indoor coil MUST be placed on the ret rn side of the Comfort Pl s
system in a position that will provide even air flow thro gh the coil.
If sing a factory s pplied ret rn air plen m, the plen m is config-
red to be the ho sing for the indoor coil. Remove the screws to the
plen ms access cover and slide the coil into place inside the ple-
n m. If not sing a Steffes s pplied ret rn air plen m, the installer
will need to make provisions in the plen m to accommodate the coil
and air filter.
When interfacing a Comfort Pl s system with an air conditioner, the
indoor coil can be placed on either the s pply air or the ret rn air
side of the system.
The condensate drain trap, in a heat p mp or air conditioner installa-
tion, sho ld be designed for the vac m in which the system is
operating. Typically, taller traps are better s ited for these types of applications.
Refer to the Room Thermostat Connections Diagrams (Fig res 13, 14 and 15) for more information on interfacing
the Comfort Pl s with a heat p mp or air conditioner.
Installation n 3.08 Comfort Plus
WARNING
Risk of fire. Any one ducting system
MUST NOT contain more than one
air handling (blower) system. If the
application requires multiple Com-
fort Plus systems or it is necessary to
have multiple air handlers share the
same ductwork, you MUST contact
Steffes Corporation. There are
special installation requirements
that MUST be performed in an
application such as this.
All Comfort Plus systems are factory configured to be field connected to multi le line voltage
circuits. If a single feed line voltage circuit is desired, an o tional single feed kit is available.
SAMPLE SYSTEM IDENTIFICATION LABEL
FIGURE 11
To determine the correct wire size req ired for
each circ it feeding the Comfort Pl s, refer to
the Specifications (Page A.01) and the system's
identification label located on the lower front of
a 3100 series system and on the lower left side
of a 4100 series system. (Reference Sample
Label Fig re 11.)
Ste 1 Remove the electrical panel cover.
Ste 2 Ro te all line voltage wires thro gh a
knocko t and into the electrical panel
of the Comfort Pl s.
Ste 3 Make proper field wiring connections
to the Comfort Pl s breakers. Refer
to the Line Voltage Wiring Diagrams
(Pages A.09 - A.12) for more informa-
tion on these connections.

Circuit Breakers
LINE 2 LINE 1 LINE 2 LINE 1
CHARGE CIRCUIT #3
CHARGE CIRCUIT #2
CHARGE CIRCUIT #1
BLOWERS/CONTROLS CIRCUIT
CHARGE CIRCUIT #4
(MODEL 4130 and 4140 ONLY)
LINE 2 LINE 1 LINE 1 LINE 2 LINE 1 LINE 2
To Service (Breaker) Panel
(4100 SERIES ONLY)
CIRCUIT PHASING CONNECTIONS
FIGURE12
Installation
Comfort Plus Installation n 3.09
The 60 AMP breakers on the Comfort Plus are for internal com onent rotection only.
Sizing of the field wire and overcurrent rotection MUST be in com liance with all a li-
cable local, state, and national codes and regulations.
wTo ensure proper operation and safety, all line
voltage circuits must be segregated from low
voltage wiring in the Comfort Plus.
wTo reduce electro magnetic fields associated
with electrical circuits and to avoid induced
voltage on sensors and electronic devices, the
circuit phases MUST be alternated as shown in
Figure 12.
IMPORTANT
PEAK CONTROL CONNECTIONS
Steffes ETS heating eq ipment may be controlled by the Power Company
via a peak control signal. This signal
can be sent to the eq ipment sing a
Steffes Power Line Carrier control
system, low voltage wiring, a Steffes
Time Clock Mod le, or line voltage
wiring. In applications tilizing
a tomatic charge control, o tdoor
temperat re information is req ired
and can be received via an o tdoor
sensor or power line carrier control system.
The Comfort Pl s heating system is factory config red
for low voltage wire control and is set to charge when
the tility peak control switch closes. Refer to the
Config ration Men (Pages 3.13-3.14) for information
on config ring the system for the application.
Never install any wiring in
a line voltage compartment
of the Comfort Plus unless
it is rated for line voltage.
IMPORTANT
Terminal Block Coding
RP = Peak Control Inp t Common
P = Peak Control Inp t
AP = Anticipated Peak (Pre-Peak) Control Inp t
COM = Peak Control O tp t Common
NC = Peak Control O tp t (Normally Closed)
NO = Peak Control O tp t (Normally Open)
LOW VOLTAGE (DIRECT WIRED) EAK CONTROL
If sing the low voltage peak control option, the Comfort Pl s is direct wired to the power company's peak control
switch. Field connections from the peak control switch are made to the low voltage terminal block thro gh a low
voltage knocko t located on the left side of electrical panel.
Ste 1 Ro te a low voltage circ it from the power companys load control or peak signaling device to the termi-
nal block inside the electrical compartment of the Comfort Pl s.
Ste 2 Connect the field wiring to positions "RP" and "P" on the terminal block as shown in Fig re 13.
To control other devices, refer to the Auxiliary Load Control on Page 3.12.
PEAK CONTROL
TERMINAL CONNECTIONS
FIGURE 13
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
Model Control Crct Chrg Crct #1 Chrg Crct #2 Chrg Crct #3 Chrg Crct #4
3120 - 14.0kW 6.00 29.17 29.17 N/A N/A
3120 - 17.0kW 6.00 36.46 36.46 N/A N/A
3120 - 21.6kW 6.00 45.00 45.00 N/A N/A
4120 - 14.0kW 7.00 21.88 21.88 14.58 N/A
4120 - 19.2kW 7.00 30.00 30.00 20.00 N/A
4120 - 24.8kW 7.00 38.75 38.75 25.83 N/A
4130 - 28.8kW 7.00 30.00 30.00 30.00 30.00
4130 - 37.2kW 7.00 38.75 38.75 38.75 38.75
4140 - 38.4kW 7.00 40.00 40.00 40.00 40.00
4140 - 45.6kW 7.00 47.50 47.50 47.50 47.50
Full Load Current
(240VAC only - Circuit deration not included)

Installation n 3.10 Comfort Plus
OWER LINE CARRIER ( LC) EAK CONTROL
The Steffes Power Line Carrier (PLC) control system has the ability to comm nicate with the system thro gh the
existing electrical circ its in the str ct re. With the power line carrier option, direct wired low voltage connections
from the power company's peak signaling switch connect directly to the transmitting device. The switch signals
peak control times to the transmitter, the transmitter sends the signals to the Comfort Pl s system, which receives
this information and responds accordingly.
In addition to providing peak control signals, the transmitter also provides o tdoor temperat re information for
a tomatic charge control, room temperat re set back, and anticipated peak tility control signals (if applicable).
The PLC system is optional and m st be ordered separately. If tilizing a PLC system, an Owner's and Installer's
man al will accompany the transmitting device. Refer to this man al for information on the installation and
operation of the power line carrier control system.
TIME CLOCK MODULE EAK CONTROL
The Steffes Time Clock Mod le is another option for providing a peak control signal to the Comfort Pl s. The
optional time clock mod le mo nts inside the line voltage electrical compartment and interfaces with the relay
board via an interface cable. Peak control times MUST be programmed into the system once the mod le is
installed to enable the time clock feat re. Refer to the instr ctions provided with the time clock mod le for more
information on the installation and operation of this device.
LINE VOLTAGE EAK CONTROL
Line voltage control is also an option, b t is not the preferred method of control as it is s ally more complex and
expensive. If line voltage control is tilized, the controls circ it m st be powered with an ninterr pted circ it. An
external switching device, s ch as a relay panel, is necessary to directly control the heating element charging
circ its. If relying on this method of control, the display on the system m st contin o sly display a brick core
operating mode of C (charge) regardless of whether it is an off-peak or on-peak period.
LOW VOLTAGE ELECTRICAL CONNECTIONS - OUTDOOR
TEMPERATURE SENSOR (RECOMMENDED)
Installation Methods: A) Hard wired to system to the two "o tdoor"
terminals (defa lt)
OR
B) Connected to Power Line Carrier (PLC)
Theory of O eration: The o tdoor sensor monitors o tdoor temperat re
and provides this information to the system. The
system responds by a tomatically storing heat in
its brick core according to o tdoor temperat re
and the heating req irements.
Location of: The o tdoor sensor m st be placed in a location where it can acc rately sense o tdoor tempera-
t re and is not affected by direct s nlight or other so rces of heat or cool.
Wiring: ·Ro te low voltage wire from the o tdoor sensor to the electrical compartment thro gh one of the low
voltage wire knocko ts.
·Connect to the two terminals labeled "o tdoor".
·If the sensor wiring is ro ted thro gh an external wall, the opening thro gh which the wire is ro ted
MUST be sealed. Fail re to do so may affect the acc racy of the o tdoor temperat re sensor.
·The o tdoor sensor is s pplied with a lead length of 40 ft. If a greater wire length is needed, it can be
extended to a total of 250 ft.
·No other loads can be controlled or s pplied thro gh this cable. It is for connection of the o tdoor
sensor ONLY.
·This low voltage cable MUST not enter any line voltage enclos re.
·Unshielded Class II (thermostat) wire can be sed as extension wire provided it is segregated from
any line voltage cabling.
Installation
If connecting to the Steffes
power line carrier (PLC)
system, follow the installa-
tion instructions in the PLC
system's Owner's and
Installer's Guide.
IMPORTANT

Comfort Plus Installation n 3.11
Installation
Low voltage wires MUST
never enter any line
voltage enclosure.
IMPORTANT
LOW VOLTAGE ELECTRICAL CONNECTIONS - ROOM
THERMOSTAT
A low voltage (24VAC) room thermostat is req ired for room temperat re
control with the Comfort Pl s Hydronic system. Steffes recommends sing a
digital thermostat. If tilizing a mechanical thermostat, a load resistor may be
necessary d e to the low c rrent draw (.01 amps) on the heat call inp t circ it
of the Comfort Pl s system. Contact the factory for information on thermostats
available from Steffes.
STAND ALONE FURNACE APPLICATION WITH VARIABLE SPEED BLOWER
CONNECTIONS SHOWN FOR SINGLE STAGE HEATING / SINGLE STAGE COOLING
(UNCONTROLLED AIR CONDITIONING)
FIGURE 14
SINGLE STAGE HEAT PUMP APPLICATION WITH VARIABLE SPEED BLOWER
FIGURE 15
IMPORTANT
è
If installing a mechanical thermostat or thermostat with antici ator, a resistor kit is required
(Order Item #1190015).
IMPORTANT
è
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Thermostat
Stage Thermostat Output
Heat
Pump
Stage
% of
Selected
CFM
Heat Call Status
on Digital
Display*
Discharge Air
Temperature
Target
1 Y1/G 1 100% HC1 L048
2 Aux/Y1/G 1 100% HC2 L049
Fan G 0 400 cfm HCF N/A
Cool Y1/G/O 1 100% COOL N/A
Emergency
H/E 0 100% HC3 L049
SINGLE STAGE HEAT PUMP
Contractor Use Only
* If multiple inputs are active,
system will display highest
Heat Call values.

Installation n 3.12 Comfort Plus
AUXILIARY LOAD CONTROL
The Comfort Pl s can be sed to provide control signals to
other loads in the application. To do so, connect low voltage
control wires to the "COM" and "NC" or the "COM" and
"NO" positions of the low voltage terminal block in the
electrical compartment of the Comfort Pl s system. (See
Fig re 17.) These contacts are rated for 30 volts, 3 amps
maxim m.
Installation
HUMIDIFIER/ELECTRONIC FILTER INSTALLATION
The Comfort Pl s is capable of being connected to a h midifier and/or an electronic air filter. If installing either
of these devices, connections to the Comfort Pl s system are made to the bottom two relays on the base I/O
relay board inside the system's electrical panel. Refer to the Line Voltage Wiring Diagrams (Page A.09-A.12)
for the location of these relays.
If installing a h midifier, connect it to the "HEAT CALL" relay on the base I/O relay board. This relay closes
d ring a heat call.
If installing an electronic air filter, connect it to the "FAN ON" relay on the base I/O relay board. This relay
closes d ring a fan call. The maxim m filter size if sing a Steffes Ret rn Air Plen m is 20" x 25" x 2.
Maximum external load should not
exceed 60 VA on the system's class
II transformer.
IMPORTANT
TWO STAGE HEAT PUMP APPLICATION WITH VARIABLE SPEED BLOWER
FIGURE 16
TYPICAL AUXILIARY LOAD CONTROL
FIGURE 17
NOTE: During off- eak (charge) eriods, the con-
tact is closed between "COM" and "NC".
W/
NO NC COM Outdoor Outdoor
CR
H/EY2Y1
AUX OG RP
22
Y1 Y2 2 OAPP
Inputs
Peak Aux.
Relay
Auxiliary Control Relay
Relay Contacts
Relay Coil
COM
NO/NC
COM
NO/NC
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IMPORTANT
è
Thermostat
Stage Thermostat Output
Heat
Pump
Stage
% of
Selected
CFM
Heat Call
Statuson
Digital Display*
Discharge Air
Temperature
Target
1 Y1/G 1 50% or 70%** HC1 L048
2 Y1/Y2/G 2 100% HC1 L048
3 Aux/Y1/Y2/G 2 100% HC2 L049
Fan G 0 400 cfm HCF N/A
Cool 1 Y1/G/O 1 50% or 70%** COOL N/A
Cool 2 Y1/Y2/G/O 2 100% COOL N/A
Emergency
H/E 0 100% HC3 L049
Contractor Use Only
TWO STAGE HEAT PUMP
* If multiple inputs are active, system
will display highest Heat Call values.
** Systems built before 1 1 2011 are
configured for 50% airflow in Stage 1.
For more information, refer to
Instruction #1200601-High Speed
Stage 1 Relay Installation.