Steffes 4140 Installers Manual

"Manufactured in North America"

OWNER'S AND

INSTALLER'S MANUAL

V18

for

COMFORT PLUS

Forced Air Heating Systems

Equipped with Variable Speed

3100

Series

4100

Series

This manual applies to heating

systems built after 01/01/2011.

Models: 3120, 4120,

4130, & 4140

Applicable to Software Version 2.00-2.19

U.S. Pat. #5201024, #5086493

Can. Pat. #2059158, #2060881

IMPORTANT

ww

w The equipment described herein is intended for installation by a qualified

ww

technician in compliance with applicable local, state, and national codes and
requirements.

ww

w To insure proper installation and operation of this product, completely read all

ww

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.

ww

w This manual should be retained by the owner upon completion of the installa-

ww

tion and made available to service personnel as required.

ww

w Disclaimer: In compiling this manual, Steffes Corporation has used its best

ww

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 in­stalled. 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.

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 instruc­tions 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 use or store materials that may produce
explosive or flammable gases near this heating system.

3. Maintain all placement and clearance requirements as
specified in this manual to ensure proper operation and
safety.

4. Keep the top of the heating system free of debris and
other objects.

5. Disconnect power to all circuits before servicing. This
heating system may be connected to more than one
branch circuit.

6. Installation of and/or service to this heating system
should be performed by a qualified technician in compli­ance with information contained herein and with national,
state, and local codes and requirements.

7. A repeated message of “CORE FAIL” indicates a need
for service by a qualified technician.

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. Installa­tion 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 clear­ance requirements can cause
improper operation of the
equipment. Maintain the place­ment and clearance require­ments specified.

BUILT-IN SAFETY DEVICES

The Comfort Plus heating system incorporates safety devices to ensure normal operating temperatures are main­tained. The chart below describes these safety devices.

DEVICE NAME FUNCTION

Core Charging High

Limit Switches

(Auto Reset)

Core Blower

Limit Switch

(Auto Reset)

Supply Air Blower

Limit Switch

Base Temperature

Limit Switch

(Auto Reset)

These limit switches monitor brick core charging and
interrupt power to the heating elements if the normal
operating temperature is exceeded.

This limit switch monitors the discharge air temperature
and interrupts power to the core blower(s) if the normal
operating temperature is exceeded:

3100 Series = 130oF (nominal)
4100 Series = 160oF (nominal)

This limit switch monitors the discharge air temperature
and interrupts power to both the supply air blower and the
core blower(s) if the normal operating temperature is
exceeded:

3100 Series = 160oF (nominal) Auto Reset
4100 Series = 190oF (nominal) Manual Reset

This limit switch monitors the temperature in the base of the
Comfort Plus and interrupts power to the core blower(s) if
the normal operating temperature is exceeded.

LOCATION

ON SYSTEM

In the limit bar panel
on the left side of the
brick storage cavity.

3100:In the discharge

air supply outlet.

4100: On the supply

air blower
assembly.

3100:In the discharge

air supply outlet.

4100: On the supply

air blower
assembly

In the base of the
system near the core
blower(s).

Comfort Plus Safety Information

Table of Contents

TC

Operation

General Operation ........................................................................................................................................................................ 1.01

System Use During Construction Phase...................................................................................................................................... 1.01

System Start-Up ........................................................................................................................................................................... 1.01

Turning System "OFF" and "ON" ............................................................................................................................................... 1.01

Control Panel ............................................................................................................................................................................... 1.02

Operating Status .......................................................................................................................................................................... 1.02

Room Temperature 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 Plus Stand - 4100 Series ................................................................................................................................................. 2.01

Down Flow Kit ............................................................................................................................................................................. 2.01

Return Air Plenum - 4100 Series ................................................................................................................................................... 2.01

Installation

Shipping and Packaging .............................................................................................................................................................. 3.01

Placement and Clearance Requirements................................................................................................................................3.02-3.03

Initial Set-up..........................................................................................................................................................................3.03-3.04

Brick Loading ............................................................................................................................................................................... 3.04

Heating Element and Air Channel Installation ............................................................................................................................. 3.05

Brick Core Temperature Sensor Installation - 4100 Series Only ................................................................................................... 3.06

Ducting .................................................................................................................................................................................3.06-3.07

Air Conditioner/Heat Pump Interface........................................................................................................................................... 3.08

Line Voltage Electrical Connections .....................................................................................................................................3.08-3.09

Low Voltage Electrical Connections

Peak Control .................................................................................................................................................................. 3.09-3.10

Outdoor Temperature Sensor ............................................................................................................................................... 3.10

Room Thermostat ..........................................................................................................................................................3.11-3.12

Auxiliary Load Control ................................................................................................................................................................. 3.12

Humidifier/Electronic Filter Installation........................................................................................................................................ 3.12

Configuration Menu .............................................................................................................................................................3.13-3.14

Installer's Final Check-Out Procedure .......................................................................................................................................... 3.15

Appendix

Specifications.............................................................................................................................................................................. A.01

Disassembling the 4100 Series Comfort Plus 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 Menu .................................................................................................................................................................................. A.14

Error Codes ........................................................................................................................................................................ A.14-A.15

Glossary ...................................................................................................................................................................................... A.16

Warranty

Table of Contents Comfort Plus

1

Operation

GENERAL OPERATION

The Steffes Comfort Plus heating system stores off-peak electricity in the form
of heat. Off-peak electricity is available during times of day or night when
electricity is plentiful and the power company can supply it at a lower cost.

Operation of the Comfort Plus heating system is automatic. When off-peak
hours are available, the system converts electricity to heat which is then stored
in its ceramic brick core. The amount of heat stored in the brick core varies in
relation to outdoor temperature, owner preference, utility peak conditions, and
the heating requirements.

A heat call from the room thermostat energizes the blowers in the Comfort Plus system. The variable speed core
blower(s) automatically adjust its speed to circulate room air through the brick core. The supply air blower then
delivers this heated air into the desired area through the duct system to maintain a constant, comfortable room
temperature.

The versatility of this system allows it to fit many applications. The Comfort Plus is designed for use as either the
sole heating source (“stand alone” furnace) or as a supplement to ducted heating systems such as heat pumps.

SYSTEM USE DURING CONSTRUCTION PHASE

Like most heating equipment manufacturers, Steffes strongly recommends that “Construction Heating Units” be
used instead of the permanent heating system during the construction phase of a new home. Use of the permanent
heating system during this phase may contaminate the duct system and/or internal areas of the heating system.
This may cause poor indoor air quality issues, systems reliability problems, and/or improper system operation once
the home is completed.

Operation

SYSTEM START-UP

On start-up of the Comfort Plus system, odors relating to first time operation of the heating components may be
experienced. Also, if not used for an extended period of time, dust may accumulate in the system. Allow the
Comfort Plus heating system to charge to its maximum 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 Plus and
oxidized. Odors can be amplified; thus, it is not recommended to operate the system if odors such as those
from paints, varnishes, or chemicals are present in the air. Air borne particles, which have been oxidized, are
expelled back into the room and may accumulate on air vents or other surfaces. Over time, these particles may
appear as a black residue, commonly referred to as soot. High concentrations of air borne particles from aerosols,
dust, candles, incense, pet hair, smoke, or cooking can contribute to poor indoor air quality and accelerate the
sooting process.

During operation, the Comfort Plus heating system may produce minor expansion noises. These noises are the
result of the internal components reacting to temperature changes.

TURNING SYSTEM "OFF" AND "ON"

The Comfort Plus element (charging) circuits may be turned “OFF” by switching ALL of the 60 AMP breakers
located on the front of the electrical panel to the DOWN position. To turn the element circuits “ON”, switch ALL
of the 60 AMP breakers to the UP position.

The 15 AMP breaker MUST remain “ON” to operate controls in the system if:

ww

w using the Comfort Plus in conjunction with a heat pump or air conditioner.

ww
ww

w using the Comfort Plus to control other loads.

ww
ww

w using the optional Steffes Time Clock Module.

ww

Comfort Plus Operation n 1.01

CONTROL PANEL

M

M

A

M

P

Operation of the Comfort Plus heating system is automatic. Operational function
settings are stored in a microprocessor on the processor control board. These settings
are modified, if necessary, through the Configuration Menu as described on Pages

3.13-3.14. In most applications, the system is configured upon installation and no
further changes are required.

Four-Digit LED Display

The four digit LED displays specific operating information. During the configuration
process, the configuration number and the values set in these configurations are
displayed for viewing and adjusting purposes.

AM and PM Indicator Lights

The AM and PM indicator lights are only utilized if the Steffes Time Clock Module is being installed and using 12

Operation

hour time display. With this module installed, the system displays time on AM/PM intervals. The light flashes next
to the active designator/symbol. The system can be configured to display military time, in which case, both the AM
and PM lights illuminate.

Mode (Edit) Button

M

Used to access menus on the system (i.e. Help Menu or Configuration Menu)
and to allow modifying of configuration settings.

Editing configuration
information may alter

Up and Down Arrow Buttons

ñ

ò

Used to scroll up or down when viewing or modifying.

the performance and
operation of the system.

operating functions.

CONTROL PANEL

FIGURE 1

IMPORT ANT

Interface Port

Allows technician external access for advanced operating modes, updating software, and troubleshooting.

OPERATING STATUS

The four digit LED will display various operating information as described below. Press and release the up arrow
to view this data.

Operating Mode - Indicates the current operating mode of the Comfort Plus system.

C = Off-Peak (Charge) Time
P = On-Peak (Control) Time
A = Anticipated Peak Time

Outdoor Temperature -“O”, followed by a number, indicates current outdoor temperature.

Heat Call Status - Indicates the current heat call status 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 number, indicates the
current percentage of heat stored in the brick core. “CL:_” represents a core temperature
lower than the minimum core temperature and “CL: F” represents a full core charge level.

A bar illuminates on the lower portion of
the display's second digit whenever the
heating elements are energized.

Targeted Brick Core Charge Level - “tL” (target level) followed by a number, indicates

the current percentage of brick core charge being targeted by the Comfort Plus. A display of
“tL:_” indicates that the system will not maintain any heat in the brick core and “tL: F”
indicates a full core charge target level.

Operation n 1.02 Comfort Plus

ROOM TEMPERATURE CONTROL

The room temperature set point is adjusted at the wall thermostat. If room temperature drops below the thermo­stat set point, the thermostat initiates a heat call and energizes the blowers in the Comfort Plus heating system. The
variable speed core blower(s) automatically adjust speed in relation to brick core temperature and duct temperature
to circulate room air through the brick core. The supply air blower then delivers the heated air into the living area
through the duct system to satisfy heating requirements. When the thermostat senses a demand greater than the
output, another stage of heating is initiated.

When used to supplement heat pump systems, the Comfort Plus replaces the resistance strip heat, which is typi­cally required as a supplement or back-up to the heat pump system. A duct sensor monitors the discharge air
temperature. If the demand for heat is at a point where the heat pump alone cannot maintain the desired duct
temperature, stored heat is used to supplement the heat pump and satisfy the heating requirements.

BRICK CORE CHARGE CONTROL

The amount of heat stored in the brick core of the Comfort Plus system is regulated automatically in relation to
outdoor temperature and the heating requirements. The outdoor sensor, supplied with the system, monitors
outdoor temperature and provides this information to the Comfort Plus. As the outdoor temperature decreases,
heating requirements increase and the system stores more heat accordingly.

CHARGE CONTROL OVERRIDE

The Comfort Plus is equipped with a charge control override feature that allows the user to force the system to
target a full core charge level. This override can be initiated or cancelled at any time. If an override is initiated,
the system targets a full core charge level during the next off-peak period. It continues to charge during off-peak
hours until the system achieves full (maximum) core charge or until the override is cancelled. Once full charge is
achieved or the override is cancelled, the system charges according to the standard configuration.

Operation

Initiating the Override Feature

Step 1 Press and hold the M, the up arrow, and the down arrow buttons at the same time.
Step 2 The faceplate will flash “FULL” and “ON”. Continue to hold all three buttons until “ON” displays

continuously.

Step 3 Release the buttons. The override is now enabled. The faceplate will return to displaying its standard

operating mode.

Manual Cancellation of the Override Feature

Step 1 Press and hold the M, the up arrow, and the down arrow buttons at the same time.
Step 2 The faceplate will flash “FULL” and “OFF”. Continue to hold all three buttons until “OFF” displays

continuously.

Step 3 Release the buttons. The override is now cancelled. The faceplate will return to displaying its standard

operating mode.

• This feature will not turn elements on during a peak period.

• This feature will cancel if power is interrupted.

MAINTENANCE AND CLEANING

The Comfort Plus heating system is easily maintained. The air filter in the return air duct of the system should be
replaced on a regular basis to ensure proper operation and to maintain overall efficiencies. No additional routine
maintenance is required.

If utilizing a heat pump or air conditioning system with the Comfort Plus, the indoor coil of the device should be
cleaned periodically as dirt accumulation may reduce system efficiency. It is important to follow the

manufacturer’s maintenance and cleaning recommendations for these devices.

Comfort Plus Operation n 1.03

2

Model Part #

3120 1301574
4120 1301572

4130/4140 1301570

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.

SINGLE ELECTRICAL FEED KIT

The Steffes Comfort Plus systems have built-in circuit
breakers. They are factory configured to be field con­nected to multiple line voltage circuits. If single feed to
the element and blowers/control circuits is desired, the
single feed kit is available to allow the system to be
powered with a one, larger line voltage circuit.

COMFORT PLUS STAND - 4100 SERIES

Some applications (such as garages) may require that the heating appliance be
elevated in order to meet building codes. The Steffes Comfort Plus stand elevates
the 4100 system 18". This stand is shipped as a kit and requires field assembly.

Stand

Accessories

Order Item #1301585

Order Item #1301578

RETURN AIR PLENUM - 4100 SERIESDOWN FLOW KIT

Order Item #1301550

Optional Accessories n 2.01 Comfort Plus

3

Installation

CAUTION

Risk of sharp edges. Can cause personal injury. Use caution
when installing and/or servicing equipment.

SHIPPING AND PACKAGING

The Comfort Plus system should always be transported in an upright position to avoid damage to internal compo­nents and insulation materials. The information below describes the items shipped with each system.

INFORMATION PACKAGE

1

(includes Owner's Manual and

Warranty Registration Card)

(adhered to outer side of shipping box)

ELEMENT SCREW KIT

2

(shipped
inside the
electrical

compartment)

HEATING ELEMENTS

4

MODEL ELEMENTS

3120 8
4120 8
4130 12
4140 16

(shipped inside the base of

the Comfort Plus)

OUTDOOR TEMPERATURE SENSOR

5

(shipped inside the

electrical compartment)

CERAMIC BRICK

3

Full Brick

(shipped separately

and packaged 4 brick

per box)

Half Brick

(shipped with brick and

packaged in a white box

consisting of 6 half brick

and 1 full brick)

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

Comfort Plus Installation n 3.01

SUPPLY AIR BLOWER ASSEMBLY

6

(4100 SERIES)

Packaging Dimensions 26 x 24.5 x 20.5

(shipped separately)

RETURN AIR PLENUM ASSEMBLY

7

(3100 SERIES)

Packaging Dimensions 27 x 40 x 4

(banded to the 3100 Series Comfort Plus for shipping)

16"

41

5

8

"

67

7

16

"

60"

10

1

8

"

53

5

8

"

5

3

8

"

1"

27"

22

7

16

"

22

5

16

"

1"

Top View

26

1

8

"

1

7

8

"

8

1

2

"

16

7

16

"

PLACEMENT AND CLEARANCE REQUIREMENTS

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)

The physical dimensions of the Comfort Plus, along with the
clearances required, MUST be taken into consideration when
choosing its location within a structure. (See Figures 2 and 3
for system dimensions and clearance requirements.)

The best installation location for this system is in a space
requiring heat so some amount of the heating requirements can
be satisfied through static dissipation from the warm outer
panels. In situations where the Comfort Plus is not installed in
an area it is intended to heat (i.e. storage closet), it is important
to account for the heat lost through static dissipation by making
proper adjustments when sizing the system. Standby heat
dissipation of up to 2.5kW can be experienced in normal opera­tion. Room air should 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 Plus is located. In
addition, a 6” x 6” non-closing type register can be cut into the
return air duct of the furnace to minimize heat build-up in the
room. This register must be installed in a manner that ensures
the air drawn into the Comfort Plus passes through the filter
first (see Figure 3A).

Risk of fire. Can cause injury or death.
w Violation of the clearance require-

ments and/or failure to provide proper
ventilation can cause improper opera­tion of the system. Maintain the
placement and clearance require­ments as specified and provide venti­lation as necessary.

ww

w Failure to maintain room temperature

ww

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.

ww

w Moving the system after install may

ww

result in equipment damage. Do NOT
move system from original installed
location.

W ARNING

In addition to the physical space requirements, the weight of the Comfort Plus must be taken into consideration
when selecting the installation surface. A level concrete floor is the best installation surface on which to place the
system, but most well supported surfaces are acceptable. If unsure of floor load capacity, consult a building
contractor or architect.

Installation

ww

w Back and Bottom = 0 clearance

ww
ww

w Left Side = 4 inches

ww
ww

w Right Side = 8 inches (from combustible material)

ww
ww

w Top = 8 inches (from combustible material)

ww
ww

w Front = 36 inches (for ease in servicing)

ww
ww

w Outer Sides of System Ducts (Return and Supply) = 0 clearance

ww
ww

w Between Ducting and System = 0 clearance (top and right side)

ww

Installation n 3.02 Comfort Plus

Special requirements must be considered if placing the system in a garage or other area where
combustible vapors may be present. Consult local, state, and national codes and regulations to
ensure proper installation. An 18" pedestal (Order Item #1301585) is available to elevate the
4100 Series.

3100 SERIES SYSTEM REQUIREMENTS

FIGURE 2

CLEARANCES

2A

Minimum clearance requirements may NOT account for
required working space for electrical connections.

2B

DIMENSIONS

2C

2D

Return

Plenum
(Factory
Supplied)

Air

4100 SERIES SYSTEM REQUIREMENTS

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

TOP VIEW

36" MIN CLEARANCE

3" MIN CLEARANCE

P
M

(4100 Series)

18" Standard

22

1
2

" if 1hp

Front View

29

3

16

13

3
4

± 1/4"

14±1/4

4100 Series

Top View

10

1

2

22

5

16

Electrical

Panel

26

3

16

"

28

3

16

"

20

1
4

49

7

16

" Standard

53

15
16

" if 1hp

24

3
4

" if 1hp

4140

68

5

8

"

4130

57

5

8

"

4120

46

5

8

"

25

1

16

"

24

1

4

"

Return Air Plenum

(Order Item
#1301550)

22

1
4

"

22 5/8"

Supply Air Plenum
(Factory Supplied)

44

11

16

"

8 3/8"

(± 1/4")

22 5/8"

M

A

M

STE

FFE

S

FIGURE 3

CLEARANCES

ww

w Back and Sides = 3 inches (from combus-

ww

tible material)

ww

w Bottom = 0 clearance

ww
ww

w Top = 6 inches (from combustible material)

ww
ww

w Front = 36 inches (for ease in servicing)

ww
ww

w Between Duct and Left Side of System =

3A

3B

ww

2 inches

ww

w Between Duct and Right Side of System =

ww

0 clearance

ww

w Outer Sides of System Ducts (Return and

ww

Supply) = 0 clearance

Minimum clearance requirements may NOT account for required working space for
electrical connections.

DIMENSIONS

3C

IMPORTANT:
Return air duct
MUST NOT enter
from the front or
back of the furnace.
Upflow, downflow, or
straight return

3D

ducting only.

INITIAL SET-UP

Step 1 Remove the Information Package from the

Comfort Plus heating system.

Step 2 Remove the heating elements from inside the

outside of the shipping box and unpackage the

base of the system.

Step 3 Move the system into its installation location.

Comfort Plus Installation n 3.03

The Comfort Plus is capable of fitting through
a 30" doorway (minimum) without disassem­bling. If necessary, the 4100 series can be
disassembled for ease in moving. To disas­semble the 4100 Series Comfort Plus, refer to
the disassembly instructions (Page A.02) for
more information.

The 3100 series can NOT be disassembled.

Risk of improper operation or equipment dam­age. Read and follow installation instructions
carefully.

ww

w Remove the Comfort Plus system from its

ww

shipping pallet before installing.

ww

w Leveling legs should be extended no more

ww

than one inch.

ww

w DO use and follow generally accepted safety

ww

practices when handling insulation material.

ww

w DO have equipment installed by a qualified

ww

technician in compliance with all applicable
codes and regulations.

IMPORTANT

Installation

Step 4 Once in place, adjust the leveling legs on the bottom of the system as necessary to prevent rocking. If not

i.e.: Rows 2, 4, 6, 8, 10 and 12 in 4140

Front

Indicator

i.e.: Rows 1, 3, 5, 7, 9, and 11 in 4140

Front

Indicator

4120 - Load in Row 5

4130 - Load in Row 4 and 8

4140 - Load in Row 6 and 12

Half Brick

Forward Facing Indicator

Rear Facing Indicator

Half Brick

Indicator in Brick

placed properly the system may bend or twist during the brick loading process, making element and brick
core temperature sensor installation difficult. Leveling legs should be extended no more than one (1) inch.

Step 5 Remove the painted front panel of the electrical compartment by removing the screws along the edges.

Locate the element screw kit and the outdoor sensor.

Step 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 pulling the bottom of the panel forward and down.

Step 7 Locate the element wiring harnesses behind the front painted panel. Carefully position them to avoid

damage during the brick loading and wiring processes.

Step 8 4100 SERIES ONLY. Locate the brick core temperature sensor(s) behind the front panel and discon-

nect them from their shipping position. Carefully position the sensor(s) to avoid damage during brick
loading and wiring.

Models 4130 and 4140 have two brick core temperature sensors.

Step 9 Remove the galvanized front panel and set it aside.
Step 10 Starting at the bottom, carefully lift the two insulation 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
compliance with generally accepted safety practices.

Step 11 Remove the front air channel by pulling out on the bottom of the air channel on a 3100 series or the top of

the air channel on a 4100 series.

BRICK LOADING

W ARNING

Load the brick, one row at a time, using a left side, right side, center pattern.
Start at the back of the brick core and work forward. Make sure the brick are
placed so the grooved side is facing up and the ridges are on the left and right.
(See Figure 6.)

BRICK INSTALLATION TIPS:

• Install bricks carefully to avoid damage to the insulation panels.

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.

• Remove loose brick debris to prevent uneven stacking of brick, as this can make installation of the elements

and the brick core temperature sensor(s) difficult.

• Brick rows MUST line up front to back and side to side.

• Half brick makes brick loading easier by evening out the stacks. Use HALF BRICK (white boxes) in the

proper rows and positions
as indicated in Figure 6.

• Alternate the direction of

FIGURE 4

FIGURE 6

the brick’s indicator in
every other brick row.
See Figures 4 and 5.

• All bricks in odd

numbered rows (1, 3, 5,
7, 9, and 11) must have
the indicator facing

FIGURE 5

forward as shown in
Figure 4.

• All bricks in even

numbered rows will have
indicator facing back.
See Figure 5.

Installation n 3.04 Comfort Plus

HEATING ELEMENT AND AIR CHANNEL INSTALLATION

3
4

"

Required Clearance Between

Element Termination and Metal

Panels is 1/2" (3/4" Nominal)

Element Connection

Electrical

Panel

Front Air

Channel

BRICK

CORE

SIDE VIEW

Outlet

Inlet

Step 1 After all brick are loaded, insert the heating elements be-

tween the brick layers, sliding them in until the element ends
embed into the side cutouts of the brick cavity.

W ARNING

3100 Series: The threaded screw tabs on the wire connec­tion terminals should 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 upward, element-to-wiring harness connections
(Figure 7) will be difficult. Be sure the elements are slid into
the brick core properly to ensure correct clearance between
the terminal connections and any surfaces within the system
as shown in Figure 7.

HAZARDOUS VOL T AGE: Risk of electric
shock. Can cause injury or death.

ww

w DO NOT remove the electrical panel

ww

cover while system is energized.

ww

w Position elements properly to avoid

ww

short circuiting them against metal
surfaces.

ww

w Protect element lead wires from front

ww

panel screws and any field installed
screws to avoid short circuit.

Step 2 Install the front air channel with the air deflectors (arrow shaped pieces) facing inward and with the

narrow ends of the deflectors pointing up.

3100 Series: Place top portion in first.
4100 Series: Place bottom portion in first (see Figure 7.)

Step 3 Lower the insulation blankets back into position, one at a time. Carefully tuck the sides of the insulation into

the edges, corners, and around the exposed portions of the heating elements to ensure maximum efficiency.

Step 4 Reinstall the galvanized front panel and secure it to the Comfort Plus system using the screws that were

originally removed.
3100 Series: Slide the top of this panel inside the upper lip of the top painted panel. The bottom should

rest on the outside of the cavity and secure 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

outside of the cavity.

Step 5 Carefully route wiring harnesses and connect them to the heating elements, using screws provided in the

hardware package. Make connections with screw heads up and threads pointing down. Element screws
should be tightened to 14 inch lbs. Refer to Element Connection (Figure 7) for proper positioning.

Step 6 The painted front panel can now be installed on 3100 systems. If installing a 4100 system, the brick core

temperature sensor(s) must be installed prior to putting the painted front panel in place.

ELEMENT INSTALLATION

FIGURE 7

AIR CHANNEL PLACEMENT

FIGURE 8

TOP

Comfort Plus Installation n 3.05

BRICK CORE TEMPERATURE SENSOR INSTALLATION -

Jumper

½ HP Variable

Speed CFM

A 1000

B 1200
C 1400
D 1600

4100 SERIES ONLY

Step 1 Remove the screw(s) by the brick core temperature sensor hole(s) in

the galvanized front panel.

Models 4130 and 4140 have an upper and a lower brick
core temperature sensor.

Step 2 Insert the brick core temperature sensor(s) through the hole(s) in the

galvanized front panel. If installing a system with two sensors, be sure
the one marked "upper" is installed in the upper opening and the one
marked "lower" is installed in the lower opening. The sensor(s) must

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.

pass through the blanket insulation and into the brick core. Holes have
not been predrilled through the insulation. Use the sensor(s) to aid in making a passageway by rotating
the sensor(s) side-to-side while gently pushing inward.

Step 3 Once the brick core sensor(s) is installed, put the screw(s) back into position in the galvanized front panel

to hold the sensor(s) in position and to provide the electrical ground.

Step 4 Check the non-insulated element terminations to make sure they do not come within 1/2" of any surface

area on the system.

Step 5 Re-install painted front panel, using previously removed screws.

CAUTION

DUCTING & AIR FLOW

For air delivery, the Comfort Plus is equipped with a
variable speed supply air blower. When interfacing
with a heat pump, the A-Coil MUST be placed on the
return air side.

To maintain a room temperature 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 cut
into the return air duct. Refer to Placement and
Clearance Requirements (Page 3.02-3.03) for more
information.

3100 SERIES

The 3100 series is factory configured for a right-to­left air flow.

Step 1 Assemble the factory supplied return air plenum

per the assembly instructions.

Step 2 Once assembled, set the plenum on the right side

of the system with the air filter and indoor coil
access covers facing forward. Line up the pre­drilled holes on the system with the holes in the
flanges of the plenum and attach using the screws
provided in the plenum's hardware package.

Step 3 Insert the air filter into the filter rack.
Step 4 Connect return air duct to top of return air plenum.

HAZARDOUS VOLTAGE:
Risk of electric shock. Can cause injury or death.

w Do install ducting before energizing the system.
w Do NOT operate the Comfort Plus without ducting

w Proper duct design and air flow are critical to

W ARNING

installed to both the air inlet and outlet.

achieve optimum system performance. A poorly
designed duct system and/or improper air flow can
cause system inefficiencies, air noise, and conden­sate drain problems. In applications where poor air
flow conditions exist along with high humidity, it
may be necessary to install a secondary conden­sate drain pan. (Order Item #1301576).

FIGURE 7

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.

Step 5 Connect the supply air duct in the structure directly to the system's air outlet located on the top of the

system.

Step 6 Adjust the CFM setting at the variable speed low voltage circuit board as shown in Figure 7.
Step 7 The W/E jumper (Figure 7) MUST be in the ON position or the blower will not operate with an "E" call

from the thermostat.

Installation n 3.06 Comfort Plus

4100 SERIES

Air

Holes

Plenum Support Bracket

Radiant Heat Shield

Jumper

½ HP Variable

Speed CFM

1 HP Variable

Speed CFM

A 1000

1200

B 1200

1400

C 1400

1600

D 1600

2000

The 4100 series is factory configured for a left-to-right or right­to-left airflow. In either airflow direction, the holes directly
above the air outlet on the right side of the 4100 Series MUST
be contained in the duct system. (See Figure 8 for reference
to these air holes.)

If a down flow configuration is desired with the 4100 series, a
down flow kit must be ordered from the factory (Order Item
#1301578) and the system MUST be raised a minimum of 10"
off the ground. An 18" pedestal is available (Order Item
#1301585) to elevate the Comfort Plus.

Step 1 Unbox the supply air blower plenum assembly.
Step 2 Remove and discard metal plate securing supply air

blower to plenum assembly.

Step 3 Locate the plenum support bracket shipped in the

plenum box. Attach the bracket to the supply air side
using the blunt tip screws supplied in the plenum
assembly hardware package. Refer to Figure 8 for
proper positioning of the plenum support bracket.

Step 4 Attach the supply blower wiring harness located in

the base of the system to the blower using the connections located
on the ends of the harness. Be sure to place any excess wiring in
the base of the system below the radiant heat shield (Figure 8).

4100 SERIES

SUPPLY AIR PLENUM ATTACHMENT

FIGURE 8

CAUTION

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.

FIGURE 9

Step 5 Verify that the blower is installed in the plenum with the motor

facing away from the system (Figure 9).

Step 6 Attach the supply air blower plenum to the Comfort Plus by drilling

two 1/8” holes per edge and using the self tapping screws supplied
in the hardware package.

Step 7 Connect both the return air and supply air ducting systems in the

structure to the Comfort Plus system. Be sure the air holes just
above the air outlet on the right side are contained in the duct
system. (See Figure 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" opening must be installed into the area where the sys­tem is located. In addition, a 6" x 6" non-closing type 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.

Step 8 Connect the supply air duct in the

structure directly to the system's air
outlet located on the top panel.

Step 9 Adjust the CFM setting at the vari-

able speed low voltage circuit board
as shown in Figure 10.

FIGURE 10

Step 10 The W/E jumper (Figure 10) MUST

be in the ON position or the blower
will not operate with an E call from
the thermostat.

Comfort Plus Installation n 3.07

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.

AIR CONDITIONER/HEAT PUMP INTERFACE

When interfacing the Comfort Plus system with a heat pump, the
indoor coil MUST be placed on the return side of the Comfort Plus
system in a position that will provide even air flow through the coil.

WARNING

If using a factory supplied return air plenum, the plenum is config­ured to be the housing for the indoor coil. Remove the screws to the
plenum’s access cover and slide the coil into place inside the ple­num. If not using a Steffes supplied return air plenum, the installer
will need to make provisions in the plenum to accommodate the coil
and air filter.

When interfacing a Comfort Plus system with an air conditioner, the
indoor coil can be placed on either the supply air or the return air
side of the system.

The condensate drain trap, in a heat pump or air conditioner installa-

Risk of fire. Any one ducting system
MUST NOT contain more than one
air handling (blower) system. If the
application requires multiple Com­fort 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.

tion, should be designed for the vacuum in which the system is
operating. Typically, taller traps are better suited for these types of applications.

Refer to the Room Thermostat Connections Diagrams (Figures 13, 14 and 15) for more information on interfacing
the Comfort Plus with a heat pump or air conditioner.

LINE VOLTAGE ELECTRICAL CONNECTIONS

In standard configuration, the Comfort Plus is wired for connec-

W ARNING

HAZARDOUS VOL TAGE: Risk of electric
shock. Can cause injury or death. Do not

Installation

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.

tion to 240V, however, the element circuits can also be con­nected to 208V. A 208V connection derates the charging input
of the system by 25%. If a system rated specifically for 208V
or 277V is required, contact the factory. The controls circuit in
the Comfort Plus system MUST be connected to 240V/208V.

The 60 amp breakers located in the electrical compartment on
the Comfort Plus feed the core charging (element) circuits. The
15 amp breaker feeds the controls and blowers circuit.

If single feed to the element and blowers/control circuits is desired, the single feed kit is available to allow the system
to be powered with a one, larger line voltage circuit.

All Comfort Plus systems are factory configured to be field connected to multiple line voltage
circuits. If a single feed line voltage circuit is desired, an optional single feed kit is available.

To determine the correct wire size required for
each circuit feeding the Comfort Plus, refer to
the Specifications (Page A.01) and the system's

SAMPLE SYSTEM IDENTIFICATION LABEL

FIGURE 11

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 Figure 11.)

Step 1 Remove the electrical panel cover.
Step 2 Route all line voltage wires through a

knockout and into the electrical panel
of the Comfort Plus.

Step 3 Make proper field wiring connections

to the Comfort Plus breakers. Refer
to the Line Voltage Wiring Diagrams
(Pages A.09 - A.12) for more informa­tion on these connections.

Installation n 3.08 Comfort Plus

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

W/

NONCCOM

Outdoor

Outdoor

CR

H/E

Speed

Blower

Y1-Y2 W-E

Y2Y1

AUX

OG RP

22

Y1 Y22O APP

Aux.

Relay

Dry Contact Peak

Control Switch

Mode l Control Cr ct Chrg Crct # 1 Chrg Crc t # 2 Chrg Crc t #3 Chr g Crc t #4

31 20 - 14 .0kW 6.0 0 29 .17 29 .17 N/A N/A
31 20 - 17 .0kW 6.0 0 36 .46 36 .46 N/A N/A
31 20 - 21 .6kW 6.0 0 45 .00 45 .00 N/A N/A
41 20 - 14 .0kW 7.0 0 21 .88 21 .88 14 .58 N/A
41 20 - 19 .2kW 7.0 0 30 .00 30 .00 20 .00 N/A
41 20 - 24 .8kW 7.0 0 38 .75 38 .75 25 .83 N/A
41 30 - 28 .8kW 7.0 0 30 .00 30 .00 30 .00 30 .00
41 30 - 37 .2kW 7.0 0 38 .75 38 .75 38 .75 38 .75
41 40 - 38 .4kW 7.0 0 40 .00 40 .00 40 .00 40 .00
41 40 - 45 .6kW 7.0 0 47 .50 47 .50 47 .50 47 .50

Fu ll L oa d Cu rre nt

(240V AC only - Circuit deration no t inc luded)

FIGURE12

IMPORTANT

ww

w To ensure proper operation and safety, all line

ww

voltage circuits must be segregated from low
voltage wiring in the Comfort Plus.

ww

w To reduce electro magnetic fields associated

ww

with electrical circuits and to avoid induced
voltage on sensors and electronic devices, the
circuit phases MUST be alternated as shown in
Figure 12.

The 60 AMP breakers on the Comfort Plus are for internal component protection only.
Sizing of the field wire and overcurrent protection MUST be in compliance with all appli­cable local, state, and national codes and regulations.

PEAK CONTROL CONNECTIONS

Steffes ETS heating equipment may be controlled by the Power Company
via a peak control signal. This signal
can be sent to the equipment using a
Steffes Power Line Carrier control
system, low voltage wiring, a Steffes
Time Clock Module, or line voltage
wiring. In applications utilizing
automatic charge control, outdoor
temperature information is required

Never install any wiring in
a line voltage compartment
of the Comfort Plus unless
it is rated for line voltage.

and can be received via an outdoor
sensor or power line carrier control system.

The Comfort Plus heating system is factory configured
for low voltage wire control and is set to charge when
the utility peak control switch closes. Refer to the
Configuration Menu (Pages 3.13-3.14) for information
on configuring the system for the application.

LOW VOLTAGE (DIRECT WIRED) PEAK CONTROL

If using the low voltage peak control option, the Comfort Plus 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 through a low
voltage knockout located on the left side of electrical panel.

Step 1 Route a low voltage circuit from the power company’s load control or peak signaling device to the termi-

Step 2 Connect the field wiring to positions "RP" and "P" on the terminal block as shown in Figure 13.

Comfort Plus Installation n 3.09

nal block inside the electrical compartment of the Comfort Plus.

To control other devices, refer to the Auxiliary Load Control on Page 3.12.

IMPORTANT

PEAK CONTROL

TERMINAL CONNECTIONS

FIGURE 13

Terminal Block Coding

RP = Peak Control Input Common

P = Peak Control Input

AP = Anticipated Peak (Pre-Peak) Control Input

COM = Peak Control Output Common

NC = Peak Control Output (Normally Closed)
NO = Peak Control Output (Normally Open)

Installation

POWER LINE CARRIER (PLC) PEAK CONTROL

The Steffes Power Line Carrier (PLC) control system has the ability to communicate with the system through the
existing electrical circuits in the structure. 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 Plus system, which receives
this information and responds accordingly.

In addition to providing peak control signals, the transmitter also provides outdoor temperature information for
automatic charge control, room temperature set back, and anticipated peak utility control signals (if applicable).

The PLC system is optional and must be ordered separately. If utilizing a PLC system, an Owner's and Installer's
manual will accompany the transmitting device. Refer to this manual for information on the installation and
operation of the power line carrier control system.

TIME CLOCK MODULE PEAK CONTROL

The Steffes Time Clock Module is another option for providing a peak control signal to the Comfort Plus. The
optional time clock module mounts 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 module is
installed to enable the time clock feature. Refer to the instructions provided with the time clock module for more
information on the installation and operation of this device.

LINE VOLTAGE PEAK CONTROL

Line voltage control is also an option, but is not the preferred method of control as it is usually more complex and
expensive. If line voltage control is utilized, the controls circuit must be powered with an uninterrupted circuit. An
external switching device, such as a relay panel, is necessary to directly control the heating element charging
circuits. If relying on this method of control, the display on the system must continuously display a brick core
operating mode of “C” (charge) regardless of whether it is an off-peak or on-peak period.

Installation

LOW VOLTAGE ELECTRICAL CONNECTIONS - OUTDOOR
TEMPERATURE SENSOR (RECOMMENDED)

Installation Methods: A) Hard wired to system to the two "outdoor"

terminals (default)

OR

B) Connected to Power Line Carrier (PLC)

Theory of Operation: The outdoor sensor monitors outdoor temperature

and provides this information to the system. The
system responds by automatically storing heat in
its brick core according to outdoor temperature
and the heating requirements.

Location of: The outdoor sensor must be placed in a location where it can accurately sense outdoor tempera-

ture and is not affected by direct sunlight or other sources of heat or cool.

Wiring: • Route low voltage wire from the outdoor sensor to the electrical compartment through one of the low

voltage wire knockouts.

• Connect to the two terminals labeled "outdoor".

• If the sensor wiring is routed through an external wall, the opening through which the wire is routed

MUST be sealed. Failure to do so may affect the accuracy of the outdoor temperature sensor.

• The outdoor sensor is supplied 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 supplied through this cable. It is for connection of the outdoor

••

sensor ONLY.

••

• This low voltage cable MUST not enter any line voltage enclosure.

••

• Unshielded Class II (thermostat) wire can be used as extension wire provided it is segregated from

any line voltage cabling.

If connecting to the Steffes
power line carrier (PLC)
system, follow the installa­tion instructions in the PLC
system's Owner's and
Installer's Guide.

IMPORTANT

Installation n 3.10 Comfort Plus

LOW VOLTAGE ELECTRICAL CONNECTIONS - ROOM

W/

NO

NC

COM

Outdoor

Outdoor

CR

H/E

O

W-EY1-Y2

Blower

Speed

AUX

G

Y2

Y1 O

22

Y1

Y2

RP2APP

TH5110D

R

G

W

C

Y

Honeywell

R

c

To Air

Aux.

Relay

Peak

Inputs

C

Y

The Y1-Y2 Jumper must be installed.

The W-E Jumper must be installed.

Conditioner

W/

NO

NC

COM

Outdoor

Outdoor

CR

H/E

The Y1-Y2 Jumper must be installed.

A

Speed

Blower

Y1-Y2 W-E

Y2Y1

AUX

OG RP

22

Y1 Y22O APP

RL E

Aux

G

O/B

C Y R

Honeywell TH5220D

To Heat Pump

O - Reversing Valve

R - Low Voltage Hot

C - Low Voltage Common

Y - Compressor

c

Inputs

Peak

Aux.

Relay

The W-E Jumper must be installed.

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

THERMOSTAT

A low voltage (24VAC) room thermostat is required for room temperature
control with the Comfort Plus Hydronic system. Steffes recommends using a
digital thermostat. If utilizing a mechanical thermostat, a load resistor may be
necessary due to the low current draw (.01 amps) on the heat call input circuit
of the Comfort Plus 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

Low voltage wires MUST
never enter any line
voltage enclosure.

IMPORTANT

IMPORTANT

èè

è

èè

If installing a mechanical thermostat or thermostat with anticipator, a resistor kit is required
(Order Item #1190015).

SINGLE STAGE HEAT PUMP APPLICATION WITH VARIABLE SPEED BLOWER

FIGURE 15

IMPORTANT

èè

è

èè

Installation

Comfort Plus Installation n 3.11

* If multiple inputs are active,

system will display highest
Heat Call values.

TWO STAGE HEAT PUMP APPLICATION WITH VARIABLE SPEED BLOWER

W/

NO

NC

COM

Outdoor

Outdoor

CR

H/E

Y2Y1

AUX

OG RP

22

Y1 Y22O APP

Inputs

Peak Aux.

Relay

Auxiliary Control Relay

Relay Contacts

Relay Coil

COM

NO/NC

COM

NO/NC

W/

NO

NC

COM

Outdoor

Outdoor

CR

H/E

The Y1-Y2 Jumper must be removed.

Speed

Blower

Y1-Y2 W-E

Y2

Y1AUX OG RP

22

Y1

Y2

2

O APP

RL Y2

Aux

G

O/B

C Y R

Honeywell TH5320U

Y1 - Compressor Stage 1

To Heat Pump

O - Reversing Valve

R - Low Voltage Hot

C - Low Voltage Common

Y2 - Compressor Stage 2

c

Inputs

Peak

Aux.

Relay

The W-E Jumper must be installed.

Thermostat

Stage

Thermostat

Output

Heat
Pump
Stage

% of

Selected

CFM

Heat Call
Status on

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

FIGURE 16

IMPORTANT

èè

è

èè

* 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.

AUXILIARY LOAD CONTROL

Installation

The Comfort Plus can be used 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 Plus system. (See
Figure 17.) These contacts are rated for 30 volts, 3 amps
maximum.

IMPORTANT

Maximum external load should not
exceed 60 VA on the system's class
II transformer.

HUMIDIFIER/ELECTRONIC FILTER INSTALLATION

The Comfort Plus is capable of being connected to a humidifier and/or an electronic air filter. If installing either
of these devices, connections to the Comfort Plus 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 humidifier, connect it to the "HEAT CALL" relay on the base I/O relay board. This relay closes
during 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 during a fan call. The maximum filter size if using a Steffes Return Air Plenum is 20" x 25" x 2.

Installation n 3.12 Comfort Plus

TYPICAL AUXILIARY LOAD CONTROL

FIGURE 17

NOTE: During off-peak (charge) periods, the con-

tact is closed between "COM" and "NC".

CONFIGURATION MENU

Configuration

Number

Power Line

Carrier (PLC)

Peak Control

Low Voltage Direct Wire Peak Control

Time Clock Module

Peak Control

Line Voltage Peak

Control

Peak Switch Closed

for Charging

Peak Switch Open

for Charging

Outdoor Sensor

(Factory Default)

No Outdoor

Sensor

Outdoor

Sensor

No Outdoor

Sensor

Outdoor

Sensor

No Outdoor

Sensor

Outdoor

Sensor

No Outdoor

Sensor

C000

5 5 6 5 6 5 6 5 6

C001

50°F 50°F 50°F 50°F 50°F 50°F 50°F 50°F 50°F

C002

10°F 10°F 10°F 10°F 10°F 10°F 10°F 10°F 10°F

C003

Match to the

Channel Selected

at PLC

0 0 0 0 0 0 0 0

C004

8 9 8 9 8 13 12 9 8

C005

0 1 1 0 0 0 0 1 1

The Steffes Comfort Plus heating system has a Configuration Menu, which
allows the system to be customized to the power company and consumer’s
needs. This menu can be accessed on start-up and allows configuration
settings to be easily adjusted.

To access the Configuration Menu:
Step 1 Energize the system. Access to the Configuration Menu is allowed

If access to Configura­tion Menu times out, the
15 amp circuit breaker
must be powered off and
back on to re-enter the
menu.

for the first two (2) minutes of operation. If the system has been
energized for more than two (2) minutes, the 15 amp circuit breaker must be powered off and back on to
gain access to this menu.

Step 2 Press and release the M button until faceplate displays “CONF”.
Step 3 Press the up arrow once and the faceplate will display “C000”. The faceplate will flash between “C000”

and the corresponding configuration value.

Step 4 If necessary, edit the configuration value by pressing and holding the M button while using the up or the

down arrow button to change the value.

Step 5 Once the value is correct, release the buttons and press the up arrow button to go to the next configura-

tion (C001,C002, etc.).

Step 6 Repeat steps 4 through 5 until all configuration settings have been adjusted to the desired values.

IMPORTANT

Step 7 Once configured, use the down arrow to leave the Configuration Menu.

In most applications only a few, if any, configuration changes will be necessary. Determine which method of
peak control is being utilized and configure as follows:

C000 Off-Peak Method of Charge Control - Sets the method of brick core charging to be used during off-

peak (charge) periods.

C001 Start Brick Core Charge Set Point - If utilizing automatic charge control as set in C000, this value

indicates the outdoor temperature at which the system starts charging.

C002 Full Brick Core Charge Set Point - If utilizing automatic charge control as set in C000, this value

indicates the outdoor temperature at which the system targets a full core charge.

C003 Power Line Carrier (PLC) Channel Selection – This value must match the channel selected at the

Steffes PLC transmitting device. A value of zero indicates PLC communication is disabled.

C004 Optional Controls Configuration - Tells the heater what controls are being used.
C005 Control Switch Configuration - If utilizing power line carrier control, the Steffes Time Clock Module, or

line voltage peak control this value MUST be zero.

Installation

Comfort Plus Installation n 3.13

* Power Company controls vary from one area to another. Check with the power provider for the

Configuration

Number

3100 Series 4100 Series

Heat Pump

No Heat

Pump

Heat Pump

No Heat

Pump

Reversing Valve

Energized for

Cooling

Reversing Valve

Energized for

Heating

Reversing Valve

Energized for

Cooling

Reversing Valve

Energized for

Heating

C006 2 130 2 3 131 3
C007 30 30 30 30 30 30
C008 5°F 5°F 5°F 5°F 5°F 5°F
C009 5°F 5°F 5°F 5°F 5°F 5°F
C010 90°F 90°F 115°F 90°F 90°F 115°F
C011 70°F 70°F 70°F 70°F 70°F 70°F
C012 60°F 60°F 60°F 60°F 60°F 60°F

C013 - C021 Refer to the Time Clock Installation Instructions

proper setting.

C006 Output Control Configuration - Configures the output controls of the Comfort Plus system. To deter-

mine the value, check the options desired from the list below. Then, add the numbers from the “Value”
column and enter the sum into this location.

Value Option Selected

2 All 3100 Series Systems.
3 All 4100 Series Systems.
8 Enables compressor control if there is a "COOL" call during a peak (control) time.

32 If it is a peak (control) period and the Comfort Plus receives a cooling call, the com-

Installation

pressor will turn off and on in 20 minute intervals (off 20 minutes, on 20 minutes, off 20
minutes, etc.).

128 Interfaces Comfort Plus with a heat pump that has a reversing valve which is energized

for heating.

C007 Charge Factor - This configuration should be set to a value of 30.

C008 through C010 configurations are only applicable if the Comfort Plus system is being used in
conjunction with a heat pump.

C008 Heat Pump Compressor Outdoor Lock-Out Temperature for Off-Peak or Anticipated Peak

Modes - Indicates the outdoor temperature at which the heat pump’s compressor is locked out and not

allowed to operate during an off-peak or anticipated peak period.

C009 Heat Pump Compressor Outdoor Lock-Out Temperature for On-Peak Mode - Indicates the

outdoor temperature at which the heat pump’s compressor is locked out and not allowed to operate during
an on-peak period.

C010 Minimum Discharge Air Temperature - Sets the minimum discharge air temperature the system

targets during a Stage 1 heat call.

C011 Currently not utilized in the 3100/4100 Comfort Plus systems.

Installation n 3.14 Comfort Plus

C012 Currently not utilized in the 3100/4100 Comfort Plus systems.
C013-C021 Time Clock Module Configuration - These configuration settings are used to configure the

peak control times when utilizing the optional Steffes Time Clock Module. Refer to the installation
and configuration instructions included with the module for more information.

INSTALLER'S FINAL CHECK-OUT PROCEDURE

Step 1 Verify that the operating mode displayed on the

W ARNING

HAZARDOUS VOLTAGE:
Risk of electric shock.
Can cause injury or
death. System may be
connected to more than
one branch circuit.
Disconnect power to all
circuits before servicing.
Equipment must be
serviced by a qualified
technician.

Step 4 Initiate a heat call from the room thermostat and verify that the Comfort Plus system recognizes the

heat call. Refer to the Operating Status section (Page 1.02) for more information on the various heat
call status displays. The supply air blower should operate. In an application interfacing the Comfort Plus
system with an air conditioner or heat pump, verify that this device is operating appropriately.

Step 2 Press the up arrow one time and verify that the

Step 3 Press the up arrow again and the current heat call

control panel corresponds with the power
company's peak control signal. Refer to the
Operating Status section (Page 1.02) for more
information on the proper operating mode.

outdoor temperature information displayed on the
control panel is approximately the same as the
current outdoor temperature. Refer to the Operat­ing Status section (Page 1.02) for more information
on the outdoor temperature display.

status will be displayed on the control panel. Refer
to the Operating Status section (Page 1.02) for
more information on the heat call status display.

Step 5 Initiate a cooling call from the room thermostat, if applicable, and verify that the Comfort Plus system

recognizes the “COOL” call. The supply air blower should operate. In an application interfacing the
Comfort Plus system with an air conditioner or heat pump, verify that this device is operating appro­priately.

Step 6 Press the up arrow until the targeted brick core charge level is displayed on the control panel. With the

system in an off-peak (charge) mode, initiate a charge control override (Page 1.03.) Once initiated, the
target level of the Comfort Plus should be 100 percent and the control panel should display “tL: F”. All
of the elements should be energized.

Step 7 With an amp meter, verify that the amperage of the system is correct for the installation. Refer to the

System Identification Label on the Comfort Plus heating system for information regarding the proper
amperage.

Step 8 Cancel the charge control override and verify that all elements in the system de-energize. Refer to the

Charge Control Override section (Page 1.03) for instructions on canceling the charge control override.

Step 9 Verify, once again, that the Operating Mode displayed on the control panel corresponds with the power

company's peak control signal.

Step 10 In applications utilizing the Steffes Power Line Carrier control system, complete the Installer’s Final

Check-out Procedure in the Owner’s and Installer’s Manual provided with that device.

Step 11 Instruct the homeowner on how to operate their new heating system from the thermostat.
Step 12 Complete the manufacturer's warranty card and return promptly.

Installation

Comfort Plus Installation n 3.15

A

Model

3120 4120 4130 4140

Charging Input (kW)

14.0 17.5 21.6 14.0 19.2 24.8 28.8 37.2 38.4 45.6

Single Feed: Minimum Circuit Ampacity

(240V Systems)

(Includes 25% Derate for Continuous Load)

81 99 120 81 109 138 159 203 209 247

Charging Circuits Required

(240V Systems – Multiple Feed)

2 -

40AMP

2 -

50AMP

2 -

60AMP

2 -

30AMP

& 1 –

20AMP

1 -

30AMP

& 2 –

40AMP

2 -

60AMP

& 1 –

40AMP

4 -

40AMP

4 -

50AMP

4 -

50AMP

4 -

60AMP

Maximum Core and Supply Blower Load

(240V Systems)

6 AMPS 7 AMPS

Element Voltage

240V Standard (208V and 277V optional as special factory order)

Note: The 240V element circuits can be connected to 208V in standard configurations;

however, the charging input of the system will be derated by 25%.

Blowers/System

Controls Voltage

240V/208V

Storage Capacity

kWh
BTU

86

293,432

120

426,500

180

614,160

240

818,880

Dimensions without ducting

(W x D X H in inches)

41.6 x 27 x 60 29.2 x 44.7 x 46.6 29.2 x 44.7 x 57.6 29.2 x 44.7 x 68.6

Duct

Openings (inches)

Supply Air Outlet
Return Air Inlet

10.1 x 16

16.5 x 22.5***

18 x 22.6

10.5 x 22.6***

18 x 22.6

10.5 x 22.6***

18 x 22.6

10.5 x 22.6***

Approximate System Weight 440 lbs 485 lbs 565 lbs 625 lbs

Approximate Brick Weight

1,118 lbs 1,782 lbs 2,574 lbs 3,366 lbs

Approximate Installed Weight

1,628 lbs 2,267 lbs 3,139 lbs 3,991 lbs

Number of Elements

8 8 12 16

Number of Brick

Whole Brick
Half Brick

Number

of Boxes

72

0

18

105

6

27

150

12

39

198

12

51

*1/2 HP Maximum Coil Size

Capacity
Front Access Dimensions
Inner Dimensions

(W x D x H in inches)

Up to 3½ TON**

25.5 x 22 x 30
26 x 22 x 31

1½ to 5 TON**

25.5 x 22 x 30
26 x 22 x 31

1½ to 5 TON**

25.5 x 22 x 30
26 x 22 x 31

1½ to 5 TON**

25.5 x 22 x 30
26 x 22 x 31

Appendix

SPECIFICATIONS

* The return air plenum is factory supplied only with the 3100 series system. It can be ordered as an optional piece with

the 4100 series systems. The dimensions listed are those that the factory supplied return air plenum can accommodate.
For larger coils, the return air plenum must be installer supplied. If using an air conditioning or heat pump system with
the Comfort Plus, the Comfort Plus does not include the indoor coil or the outdoor compressor system as standard
equipment.

** The Comfort Plus system can accommodate most heat pump or air conditioner indoor coils provided the heat pump or air

conditioner is sized in accordance to supply air delivery rates of the Comfort Plus system. Equipment modifications are
required to fit larger coils.

• 3120 - 1/2 HP variable speed accomodates up to 3½ ton heating/cooling systems

• 4100 Series - 1/2 HP variable speed accommodates most 1½ to 4 ton heating/cooling systems

• 4100 Series - 1 HP variable speed accommodates most 3 to 5 ton heating/cooling systems

*** Dimension does not include the return air plenum.

Appendix

nn

n A.01 Comfort Plus

nn

P

l

u

s

f

r

o

n

t

s

a

d

d

l

e

s

a

n

d

b

a

c

k

Z

-

B

r

a

c

k

e

t

L

i

m

i

t

s

a

n

d

R

i

g

h

t

S

i

d

e

S

a

d

d

l

e

i

n

c

l

u

d

e

d

Saddles and Z-brackets

can be removed if needed.

42 5/16"

Can be broken down into
individual panels.

29 3/16"

Do not remove

core limits.

28 7/8"

4140/5140

54 3/4"

4130/5130

43 3/4"

4120/5120

32 3/4"

4140/5140

56"

4130/5130

45"

4120/5120

34 1/2"

38 1/8"

29 3/16"

Including
Breakers

ALL 4100'S

45 3/4"

ALL 5100'S

48 1/4"

17 1/4"

DISASSEMBLING THE 4100 SERIES COMFORT PLUS SYSTEM

Step 1 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 pulling the bottom of the panel forward and down.

Step 2 Remove the limit zone cover.
Step 3 Remove the screws around the perimeter of the limit zone and around the bottom of the left side, right

side, and back upper panels.

Step 4 There are two white/blue wires which route from the limit zone through a knockout. These wires route

into the electrical compartment through a romex connector. Loosen the romex connector.

Step 5 Remove the electrical panel cover and locate the point where the white/blue wires connect to the black/

yellow wires. Disconnect the white/blue wires and route them up through the romex connector.

Step 6 Remove the one to two screws in the center of the upper right side panel. From the back of the system,

lift and remove the painted panels (Figure A).

Step 7 Locate the brick core temperature sensor(s) behind the front panel and disconnect them from their

shipping position. Carefully lay the sensor(s) aside to avoid damaging them.

Step 8 Rock the brick core (Figure B) to one side and lift top portion up and off the base (Figure C).
Step 9 Move the Comfort Plus heating system into the desired location, reassemble, and continue with the

installation instructions in this manual.

FIGURE A

FIGURE B

FIGURE C

(5100 Base Shown)

Comfort Plus Appendix n A.02

PARTS DIAGRAM - 3100 SERIES

25

13

15

14

19

42

17

16

8

18

19

26

43

22

3

2

1

10

7

9

6

21

37

39

20

38

40

23

5

B

r

i

c

k

S

i

d

e

V

i

e

w

4

11

28

34

27

12

29

36

33

31

35

32

24

41

30

13

VARIABLE SPEED MOTOR

PSC MOTOR

16

48

47

46

44

45

17

Appendix

Appendix n A.03 Comfort Plus

PARTS LIST - 3100 SERIES

DWG.

REF.

NO.

DESCRIPTION

3120

ITEM NO.

1 Front Painted Panel, Right Side 5940728
2 Electrical Panel Cover 5940794
3 Front Galvanized Panel 5940770
4 Standoffs, Front 5940774
5 Core Blower 1021001R
6 Heating Elements *
7 Blower Access Cover 5940796
8 Supply Air Blower Support Bracket 5940702

9 Base Temperature Limit Switch 1012008R
10 Base Temperature Limit Mounting Bracket 5940711
11 Front Air Channel 5940779
12 Brick 5903015
13 Low Voltage Panel 5940748
14 Terminal Block 12 Position 1016040
15 Terminal Block 6 Position 1016041
16 Supply Air Blower Assembly (PSC) 1041630

" Supply Air Blower Assembly (Variable Speed)

1041631

17 Supply Air Blower 1/2 HP 1075 RPM (PSC) 1040086

" Supply Air Blower 1/3 HP 850 RPM (PSC) 1040090

" Supply Air Blower 1/2 HP (Variable Speed) 1020007R
18 Supply Air Blower Capacitor 1018006R
19 Supply Air Blower Mounting Bracket 5940704
20 Breaker Standoff 5940766
21 Processor Control Board Mounting Bracket 5940746
22 PCB Processor Control Board 1023065R
23 PCB Base I/O Relay Board 1023078R
24 PCB Relay Expansion 1023067R
25 Right Front Base Painted Panel 5940764
26 Back & Left Side Base Painted Panel 5940762
27 Upper Left Side Painted Panel 5940780
28 Top Painted Panel 5940768
29 Insulation Blanket Inner 1054110

" Insulation Blanket Outer 1054115
30 Core Limit Switch 320D 1012011R

When ordering parts, please include the system model and serial numbers.

* Optional voltages are available. Contact factory with model number and serial

number of the system for information.

Comfort Plus Appendix n A.04

Appendix

PARTS LIST - 3100 SERIES CONTINUED

DWG.

REF.

NO.

DESCRIPTIO N

3120

ITEM NO.

31 Core Blower Limit Switch 130D 1012006R
32 Discharge Air High Limit Switch 160D 1012008R
33 Discharge Air Sensor 1041536R
34 Core Temperature Sensor 1041625R
35 Bottom Micropore Insulation Panel 1050124
36 Transformer 75VA 1017039
37 Breaker 15 Amp 1024000R
38 Breaker 60 Amp 1024002R
39 Interface Cable, 36" 1010016
40 Interface Cable, 12" 1010012
41 Outdoor Sensor - Knockout Style - 40' 1302044R

" Outdoor Sensor - Knockout Style - 8' 1302033
42 Faceplate Label 1159029
43 Time Clock Module (optional) 1301014
44 Harness Motor ECM Low Voltage 1011703
45 Harness Line Voltage Variable Speed 1011702
46 Harness Process Output Variable Speed 9 Pin 1011705
47 Harness Process Input Variable Speed 15 Pin 1011704
48 PCB ECM Motor Interface Variable Speed 1023082

When ordering parts, please include the system model and serial numbers.

Appendix

Appendix n A.05 Comfort Plus

PARTS DIAGRAM - 4100 SERIES

1

2

10

3

4

5

6

11

12

9

7

18

19

13

16

14

15

30

31

29

28

27

26

25

33

53

52

51

50

49

48

47

45

34

35

32

46

44

43

36

37

38

42

24

23

40

39

57

60

59

58

20

21

22

41

62

64

63

65

66

17

67

B

r

i

c

k

S

i

d

e

V

i

e

w

68

57

54

56

55

8

PSC MOTORS

VARIABLE SPEED MOTORS

22

21

70

71

72
73

69

61

1A

58

61

Comfort Plus Appendix n A.06

Appendix

PARTS LIST - 4100 SERIES

DWG.

REF.

NO.

DESCRIPTION

4120

ITEM NO.

4130

ITEM NO.

4140

ITEM NO.

1 Electrical Panel Cover 5940845 5940845 5940845

1A Breaker Filler 5940846 N/A N/A

2 Front Painted Panel 5940589 5940526 5940588
3 PCB Relay Expansion Board 1023067R 1023067R 1023067R
4 PCB Base I/O Relay Board 1023078R 1023078R 1023078R
5 Terminal Block 12 Position 1016040 1016040 1016040
6 Transformer 75VA 1017039 1017039 1017039
7 PCB Processor Control Board 1023065R 1023065R 1023065R
8 Processor Control Board Mounting Bracket

5940550 5940550 5940550

9 Breaker 15 Amp 1024000R 1024000R 1024000R
10 Breaker 60 Amp 1024002R 1024002R 1024002R
11 Breaker Standoff 5940034 5940034 5940034
12 Electrical Panel Insert Center 5940505 5940505 5940505
13 Electrical Panel Insert Left 5940504 5940504 5940504
14 Electrical Panel Insert Right 5940506 5940506 5940506
15 Harness, Breaker to Element Black 1041503 1041515 1041502
16 Harness, Relay to Element Red 1041501 1041513 1041500
17 Front Air Channel 5940515 5940521 5940514
18 Front Standoff 5940513 5940513 5940513
19 Front Galvanized Panel 5940579 5940524 5940578
20 Upper Brick Core Temperature Sensor N/A 1041525 1041525

" Lower Brick Core Temperature Sensor 1041525 1041525 1041525
21 Core Blower Spring 1159006 1159006 1159006
22 Core Blower 1021001R 1021001R 1021001R
23 Base Temperature Limit Switch 1012008R 1012008R 1012008R
24 Brick Tray 5940548 5940548 5940548
25 Insulation Block TR19 1054144 1054144 1054144
26 Heating Elements * * *
27 Brick 5903015 5903015 5903015
28 Right Side Core 5940559 5940557 5940558
29 Outdoor Sensor - Knockout Style - 40' 1302044R 1302044R 1302044R

" Outdoor Sensor - Knockout Style - 8' 1302033 1302033 1302033
30 Right Side Painted Panel 5940587 5940525 5940586
31 Right Side Standoff 5940570 5940570 5940570
32 Micropore Insulation Panel 1050122 1050121 1050120
33 Top Painted Panel 5940590 5940590 5940590
34 Core Limit Jumper 1041510 1041510 1041510
35 Left Side Front Painted Panel 5940597 5940529 5940596
36 Limit Harness Top 1041506 1041505 1041505
37 Limit Harness Bottom 1041504 1041504 1041504

When ordering parts, please include the system model and serial numbers.

Appendix

* Optional voltages are available. Contact factory with model number and serial number

of the system for information.

Appendix n A.07 Comfort Plus

PARTS LIST - 4100 SERIES CONTINUED

DWG.

REF.

NO.

DESCRIPTIO N

4120

ITEM NO.

4130

ITEM NO.

4140

ITEM NO.

38 Left Side Front Base Panel 5940580 5940580 5940580
39 Bottom Panel 5940568 5940568 5940568
40 Base Top Panel 5940566 5940566 5940566
41 Base Deflector Panel 5940502 5940502 5940502
42 Back Bottom Base Painted Panel 5940582 5940582 5940582
43 Left Side Bottom Painted Panel 5940594 5940594 5940594
44 Left Side Back Painted Panel 5940599 5940530 5940598
45 Core Limit Switch 290D 1012019R 1012019R 1012019R
46 Limit Zone Painted Cover 5940585 5940527 5940591
47 Left Side Top Painted Panel 5940584 5940584 5940584
48 Left Side Core Panel 5940561 5940565 5940560
49 Insulation Blanket Inner 1054130 1054134 1054140
50 Insulation Blanket Outer 1054132 1054136 1054142
51 Back Painted Panel 5940593 5940528 5940592
52 Galvanized Core Panel Back 5940563 5940567 5940562
53 Galvanized Core Panel Top 5940564 5940564 5940564
54 Core Blower Limit Switch 160D 1012008R 1012008R 1012008R
55 Discharge Air Sensor 1041536R 1041536R 1041536R
56 Supply Air Blower Limit Switch 190D 1012026R 1012026R 1012026R
57 Supply Air Blower Wiring Harness 1011701 1011701 1011701
58 PSC Motors with capacitor

" Supply Air Blower 1/2 HP 1075 RPM 1040086 1040086 1040086

" Supply Air Blower 3/4 HP 1075 RPM 1040091 1040091 1040091

" Variable Speed Motors

" Supply Air Blower 1/2 HP (Variable Speed) 1020007R 1020007R 1020007R

" Supply Air Blower 1 HP (Variable Speed) 1020008R 1020008R 1020008R
59 Supply Air Blower Capacitor 1018006R 1018006R 1018006R
60 Plenum Assembly 1022009 1022009 1022009
61 Blower Wheel 1021000 1021000 1021000
62 Terminal Block 6 Position 1016041 1016041 1016041
63 Electrical Panel, Main Body 5940556 5940556 5940556
64 Electrical Panel, Bottom 5940554 5940554 5940554
65 Interface Cable, 18" 1010014R 1010014R 1010014R
66 Interface Cable, 12" 1010012R 1010012R 1010012R
67 Faceplate Label 1159029 1159029 1159029
68 Time Clock Module (optional) 1301014 1301014 1301014
69 PCB ECM Motor Interface Variable Speed 1023082 1023082 1023082
70 Harness Motor ECM Low Voltage 1011703 1011703 1011703
71 Harness Line Voltage Variable Speed 1011702 1011702 1011702
72 Harness Process Output Variable Speed 9 Pin 1011705 1011705 1011705
73 Harness Process Input Variable Speed 15 Pin 1011704 1011704 1011704

When ordering parts, please include the system model and serial numbers.

Comfort Plus Appendix n A.08

Appendix

INTERNAL SYSTEM WIRING DIAGRAMS - LINE VOLTAGE

RELAY

RELAY

COM

LIMIT

75VA

TRANSFORMER

240v 24v

ELEMENT 7

EXPANSION

BOARD

#1

COM

NO

L2 240

L2 120

ELEMENT 5

RED

LIMIT

LIMIT

CORE

CORE

COMCOMCOM

NO

L1

1/4 Amp

NO

NONO

ELEMENT 1 ELEMENT 3ELEMENT 2

CORE

DAMPER

BASE IO BOARD

BLACK/YELLOW

RESISTER

RESISTOR

Element 4

Element 2
Element 1

Element 3

COM

CIRCUIT #2

CONTROLS

BLOWERS/

CIRCUIT #1

HEAT CALL

NO

COM

COM

NO

15A 60A 60A

CHARGE

CIRCUIT

CHARGE

GROUND

LUGS

BLACK

SEE NOTE

Element 7

Element 5

Element 6

HEATING ELEMENTS

Element 8

ELEMENT 8

Element

NO

COM

Relays

1, 3, 5, 7

ELEMENT 6

To

Element

2, 4, 6, 8

Relays

To

COM

BLACK

NO

NO

ELEMENT 4

RED

N.C.

N.C.

160 °

N.C.

BLACK/YELLOW

BLOWER

L2 240

FAN ON

NO

COM

5 Amp

L2 120

L1

COM

NO

1/4 Amp

BLOWER

130 °

CORE

BLUE/WHITE

160 °

BLUE

BLACK

BLACK

VARIABLE SPEED BLOWER

Line Voltage Wiring Diagram - Model 3120

240V OR 208V SYSTEMS ONLY

Use copper or aluminum conductors rated for 75oC or higher for field connection of this device.

Appendix

NOTE: Line Voltage Field Wiring Connections - See Figure 10 for information on circuit phasing

connections.

Appendix n A.09 Comfort Plus

Line Voltage Wiring Diagram - Model 4120

160 °

BLOWER

HEAT CALLFAN ON

ELEMENT 2

COM

BASE IO BOARD

#1

EXPANSION

BOARD

L2 120

L2 240

RED

COMCOM

CORE

LIMIT

WHITE/BLACK

NO

L1

1/4 Amp

LIMIT

CORE

WHITE/BLACK

ELEMENT 1

BLOWER

BLACK

CORE

DAMPER

N.C.

WHITE

RESISTOR
RESISTER

Element 2
Element 1

Element 3

Element 4

COM

COM

Element 7
Element 6
Element 5

HEATING ELEMENTS

Element 8

ELEMENT 7 ELEMENT 8

TRANSFORMER

NONO

COM COM

240v / 24v

ELEMENT 5 ELEMENT 6

75 VA

RED

Element

2,4,6

COM COM

NONONO

NO

NO

ELEMENT 3 ELEMENT 4

To

Relays

1,83,5,7

To

ElementToElement

Relays Relays

BLACK

BLACK/YELLOW

BLUE

BLUE/WHITE

RELAY RELAY

RED

BLUE

in the base of the

Heater & Plenum

Connectors located

L2 120

BLACK

CORE

L2 240
BLOWER

5 Amp

L1

BLACK

VARIABLE SPEED BLOWER

BLACK

CIRCUIT #1

CIRCUIT #3

CIRCUIT #2

CONTROLS

60A

NONO

COM

NO

NO

COM

1/4 Amp

COMCOM

15A 60A60A

CHARGE

BLOWERS/

CIRCUIT

CHARGE

CHARGE

N.C.

9 Pin Header

LUGS

GROUND

N.C.

160 °

BLUE/WHITE

MANUAL RESET

BLUE

190 °

BLUE/BLACK

BLUE/BLACK

SEE NOTE

Use copper or aluminum conductors rated for 75oC or higher for field connection of this device.

240V OR 208V SYSTEMS ONLY

NOTE: Line Voltage Field Wiring Connections - See Figure 10 for information on circuit phasing

connections.

Comfort Plus Appendix n A.10

Appendix

Line Voltage Wiring Diagram - Model 4130

DAMPER

BLOWER

LIMIT

CORE

BLACK/YELLOW

RED

75 VA

240v 24v

TRANSFORMER

WHITE/BLACK

RED

CORE

LIMIT

LIMIT

CORE

RED

BLACK/YELLOW

BASE IO BOARD

BLACK

BLACK

WHITE

160 °

CORE

N.C.

CORE

BLOWER

CIRCUIT #3

CHARGE

CIRCUIT #4

CHARGE

CIRCUIT #1

CHARGE

CIRCUIT #2

CHARGE

CIRCUIT

CONTROLS

BLOWERS/

L2 120

NO

FAN ON

RELAY

RESISTOR
RESISTER

L2 240
BLOWER

RELAY

BLUE/WHITE

NO

HEAT CALL

COM

COM

COM

L1

1/4 Amp5 Amp

NO

COM

NO

15A 60A 60A 60A 60A

BROWN

BLACK

RED

BLUE

#2

Element 2
Element 1

Element 3

Element 4

EXPANSION

ELEMENT 5

L1

L2 240

BOARD

L2 120

NO

1/4 Amp

COM

COM COM

BOARD

HEATING ELEMENTS

NO

COM COM

NO

ELEMENT 11

COM

NO

ELEMENT 12

NO

COM

Element 7

Element 5

Element 6

Element 8

Element 9

#1

ELEMENT 6

NONO

COM COMNOCOM

Element 12

Element 10

Element 11

NO NO

L2 120

L2 240

EXPANSION

L1

1/4 Amp

ELEMENT 7 ELEMENT 8

ELEMENT 9 ELEMENT 10

NO

COM

NO

COM

COM

ELEMENT 1

COM

ELEMENT 3

NO

COM

NO

ELEMENT 2

NO

COM

NO

ELEMENT 4

ToTo To

Element

2,6,10

Relays

Element

1,5,9

Relays

Element

3,7,11

Relays

To

Element

4,8,12

Relays

GROUND

LUGS

in the base of the

BLUE

9 Pin Header

Connectors located

VARIABLE SPEED BLOWER

BLACK

BLACK

BLUE/BLACK

N.C.

BLUE/WHITE

N.C.

160 °

MANUAL RESET

BLUE

190 °

BLUE/BLACK

Heater & Plenum

SEE NOTE

240V OR 208V SYSTEMS ONLY

Use copper or aluminum conductors rated for 75oC or higher for field connection of this device.

Appendix

Appendix n A.11 Comfort Plus

NOTE: Line Voltage Field Wiring Connections - See Figure 10 for information on circuit phasing

connections.

Line Voltage Wiring Diagram - Model 4140

75 VA

TRANSFORMER

240v 24v

REDRED

RED

BLACK/YELLOW

CORE

LIMIT LIMIT

CORE

WHITE/BLACK

LIMIT

CORE

LIMIT

CORE

BLOWER

CORE

BLOWER

CORE

RESISTOR

BLUE/WHITE

RESISTER
DAMPER

RED

BLACK/YELLOWBLACK/YELLOW

BLACK

BASE IO BOARD

L2 120

BLOWER

L2 240

BLACK

N.C.

160 °

WHITE

L1

RELAY

FAN ON

NO

COM

NO

RELAY

COM

HEAT CALL

1/4 Amp

COM

5 Amp

NO

COM

NO

15A 60A 60A 60A60A

CIRCUIT #3

CIRCUIT #4

BLOWERS/

CONTROLS

CIRCUIT #1

CIRCUIT #2

CIRCUIT

CHARGE

CHARGE

CHARGE

CHARGE

SEE NOTE

RelaysRelays

Relays

Relays

ELEMENT 4ELEMENT 3ELEMENT 2ELEMENT 1

Element 5

Element 2

Element 1

Element 3

Element 4

Element 15

COM

NONO

COMNOCOMCOM

NO

EXPANSION

#2

BOARD

COMCOM

NO NO

ELEMENT 14

ELEMENT 16ELEMENT 15

ELEMENT 13

NO

NO

COM

COM

Element 10

Element 7

Element 6

Element 8

Element 9

Element 11

Element 12

Element 14

Element 13

NO

ELEMENT 9

COM

NO

ELEMENT 11

HEATING ELEMENTS

ELEMENT 8ELEMENT 6ELEMENT 5 ELEMENT 7

#1

BOARD

EXPANSION

COM

NO

COM COM

NONO

COM

Element 16

COM

NO

ELEMENT 12

ELEMENT 10

NO

COM

1,5,9,13

COM

NO

2,6,10,14 4,8,12,163,7,11,15

BLACK

RED

Element

To To

Element

BLUE

BROWN

Element

To

Element

To

GROUND

LUGS

BLACK

VARIABLE SPEED BLOWER

BLACK

Connectors located

in the base of the

9 Pin Header

BLUE/BLACK

BLUE/WHITE

160 °

N.C.

190 °

BLUE

MANUAL RESET

N.C.

BLUE

BLUE/BLACK

Heater & Plenum

240V OR 208V SYSTEMS ONLY

Use copper or aluminum conductors rated for 75oC or higher for field connection of this device.

Comfort Plus Appendix n A.12

NOTE: Line Voltage Field Wiring Connections - See Figure 10 for information on circuit phasing

connections.

Appendix

INTERNAL SYSTEM WIRING DIAGRAM - LOW VOLTAGE

Relay

Inputs

Outdoor

Outdoor

Pump

VAC

24

2

Water

P3P2P1

Air

P11

W/

Y1AUX Y2

J5

Y1 Y2

RLY1

J2

D1

Blower

B
C
D

P4

P5

D2

J4

J3

P6

H/E

Speed

Blower

A

OG

J6

W/E

Y1

CR

J1

P

To Control Board

P7

2Y22

O

RP

RP8C

P9

NC

AP COM NO

Thermostat

Peak

Heat

Aux.

M

P
M

A
M

BLUE

YELLOW

TRANSFORMER

75 VA

R

C

PROCESSOR BOARD

TO LOW VOLTAGE

TO PROCESSOR
CONTROL BOARD

CIRCUIT BOARD

+

-

+

-

LOWER BRICK CORE SENSOR

UPPER BRICK CORE SENSOR

RED

YELLOW

YELLOW

RED

3120/4120/4130/4140

3120/4130/4140

"Y2"

2

YELLOW

WHITE/BLACK

RED/BLACK

WHITE/RED

ORANGE

ORANGE

BLUE/BLACK

WHITE/BLACK

YELLOW/BLACK

ORANGE

YELLOW

BLUE

WHITE

BROWN
GRAY

BLACK

GREEN

RED

WHITE

"SC"

19

"RS"

20

"W"

10

"P"
"DS"

"OS"

"C"

"O"
"G"
"AP"

"Y"

15
17

18

16

13
14

11
12

"COM"
"RP"

"E"

"NO"
"NC"

"O2"

"R"

7
8

9

5
6

3
4

YELLOW

"R"

1

SENSOR

DISCHARGE

AIR

YELLOW

1

17BROWN

BLUE/BLACK

BLUE

GRAY

19
20

18

RED

9

YELLOW/BLACK

GREEN

WHITE/BLACK
BLACK

YELLOW

ORANGE

WHITE

13
15

16

14

11
12

10

ORANGE/BLACK

YELLOW/BLACK

WHITE/BLACK

RED/BLACK

WHITE/RED

WHITE

ORANGE

5
7
8

6

3
4

2

The outdoor temperature sensor, room thermostat, and peak control device are connected via low voltage wiring.

System Low Voltage Wiring Diagram

The "R" and "C" positions in the low voltage terminal
strip may be used as a source of 24 VAC for powering
external low voltage devices (60 VA maximum).

W ARNING

HAZARDOUS VOLTAGE: Risk
of electric shock. Can cause
injury or death. All low volt­age wiring must be segre­gated from line voltage
circuits in the system.

Appendix

Appendix n A.13 Comfort Plus

HELP MENU

The Comfort Plus contains a Help Menu which may be accessed through the control panel. To access the
Help Menu, press and release the M button until the faceplate displays “HELP”. Scroll through the menu by
pressing either the up or the down arrow button.

Display
Reading Description

Fxxx Firmware Version Number - Indicates the version of software installed.
O xx Outdoor Temperature - Indicates current outdoor temperature as recognized by the system.
tL:xx Target Level - Indicates the percentage of brick core charge level the system is targeting.

During peak periods the value displays as "tL_".
CL:xx Charge Level - Indicates the percentage of heat storage currently in the brick core.
HE x Heating Elements Active - Indicates the total number of heating elements currently energized.
PC x Power Line Carrier Channel - Indicates the channel on which the system is set to receive PLC

communication signal.
P x Power Line Carrier Net Hit Rate Percentage - Indicates the percentage of "GOOD" communi-

cation packets received by the system from the PLC transmitter system.
PS x Indicates which Specialty Timer the system is currently using. The value displayed will be zero if

the Specialty Timer is not being utilized.
CC_x Charge Mode Operation - Indicates the charge control method being utilized during off-peak

periods.
CA_x A-Peak Mode Operation - Indicates the charge control method being utilized during anticipated

peak periods.
C1_x Specialty Timer #1 Charge Mode - Specialty Applications Only.
C2_x Specialty Timer #2 Charge Mode - Specialty Applications Only.
HUxx Heat Usage - Indicates the amount of input being dissipated by the system.
A_xx Target Discharge Air Temperature - Indicates the discharge air temperature that the system is

targeting.
cxxx Compressor Output Relay Delay Timer - Indicates time remaining before heat pump compressor

is energized. "c ON" indicates the heat pump is energized.

ERROR CODES

The Comfort Plus has an on-board diagnostic system to monitor various
operating conditions. If operating conditions move outside the normal operating
range, an error code is displayed on the faceplate. If there are multiple errors
simultaneously, only the highest priority error code appears. Once corrected,
the next highest priority code will be displayed on the faceplate as “Er—” (i.e.,
Er05).

Error Code Description

01 The lower core (Core A) thermocouple temperature is

out of normal range. An open, shorted, or otherwise
defective thermocouple or a circuit board which is out of
calibration can cause this.

02 The upper core (Core B) thermocouple temperature is out of normal range. This can be

caused by an open, shorted, or otherwise defective thermocouple or a circuit board which is
out of calibration.

03 Room sensor temperature is out of normal range. This can indicate an open thermistor, a

short in the wiring, or a circuit board which is out of calibration.

04 Discharge air sensor temperature is out of normal range. This can indicate an open ther-

mistor, a short in the wiring, or a circuit board which is out of calibration.

W ARNING

HAZARDOUS VOLTAGE:
Risk of electric shock. Can
cause injury or death.
System may be connected
to more than one branch
circuit. Disconnect power to
all circuits before servicing.
Equipment must be serviced
by a qualified technician.

Appendix

Comfort Plus Appendix n A.14

Error Code Description

05 Outdoor sensor (direct wired) temperature reading is out of normal range. The thermistor

circuit may be open or shorted, the processor control board may be out of calibration, or there
may be an incorrect value in L035.

06 Outdoor sensor temperature from the transmitting device (PLC system) is out of normal

range. Check the outdoor sensor attached to the transmitting device and the transmitter for
proper operation.

07 Main processor control board temperature sensor is out of normal operating range. Verify

that none of the clearances have been violated and inspect the condition of the processor
control board.

08-09 Currently not utilized.

10 Discharge air temperature has exceeded maximum standard operating temperatures.

11-19 Contact a qualified service technician.

20 There is no communication occurring between the Base I/O board and the processor control

board. This can be caused by a defective board interface cable or an unresponsive Base I/O
board.

21 There is no communication occurring with the first relay expansion board. The interface

cable may be defective or the first expansion board may be unresponsive.

22 There is no communication occurring with the second relay expansion board. The interface

cable may be defective or the second expansion board may be unresponsive.
23 There is no communication occurring with the Steffes Time Clock Module.
24 Temperature sensor offset/reference is out of range and indicates that one of the sensors or

25 Power line carrier system is active; however, no good data has been received.
26 Insufficient main control board memory. Contact a qualified service technician.
27 Insufficient permanent memory. Contact a qualified service technician.
28 Permanent memory change has been made. Press the M button to accept. This error

29 On-board communication system is not fully operable. Contact a qualified service technician.
30 Base I/O control board is in test mode. Check the jumper configuration on the circuit board.
31 Relay expansion board(s) are in test mode. Check the jumper configuration.

Appendix

39 Indicates the value in Configuration 2 (C002) has been set to a value greater than the value in

40 Press and release the M button to clear the error. If the error code reappears, contact a

41-44 Contact a qualified service technician.

the core thermocouple may be shorted to ground or the processor control board may be out of

calibration.

message indicates a change has been made to the software program; therefore, it is important

to verify that all location settings are correct for the application.

Configuration 1 (C001). The system will not charge until the value in C002 is set lower than

C001.

qualified service technician.

Cold Core The brick core temperature is below 40 degrees or the core sensing thermocouple may be

open.

Core Fail Core high limit switch may be open.

PLC Fail The system is configured for power line carrier control; however, is not receiving a valid

power line carrier communication signal.

Appendix n A.15 Comfort Plus

GLGL

OSSAROSSAR

GL

OSSAR

GLGL

OSSAROSSAR

YY

Y

YY

Anticipated Peak ~ Used only by certain power

companies as an alternative method of storing heat in
the brick core.

Automatic Charge Control ~ Method of brick core

charge regulation where a sensor monitors outdoor
temperature to automatically adjust the brick core
temperature. Indicated by an "A" on the system display.

Manual Charge Control ~ Method of brick core

charge regulation where the owner must periodically
adjust the brick core temperature setting in relation to
the outdoor temperature.

Microprocessor ~ Device on the circuit board of

the system which stores and processes the informa­tion for controlling the operation of the system.

Brick Core Charge Level ~ The amount of heat that

is stored in the brick core.

Charge Period ~ Off-peak time in which the system

is allowed to store heat in its brick core. Indicated by an
"C" on the system display.

Control Panel ~ Contains the buttons to adjust and

the display to indicate system functions.

Control Period ~ On-peak time in which the system

is not allowed to store heat in its brick core. Indicated
by an "P" on the system display.

Edit Mode ~ Process of changing or viewing the

values in a microprocessor location. This is accom­plished with the use of the M (mode) button, the ñ
(up arrow) button, and the ò (down arrow) button.

Location (Function) ~ Where the specific operating

information of the system is stored. These locations
are part of the system microprocessor and are accessed
through the control panel. Displayed as an "L" on the
faceplate when in the edit mode.

Off-peak ~ The time during the day or night when

the power company can supply electricity more
economically and may offer a special incentive such
as a reduced electric rate or billing credits for the
electricity consumed during this time. Typically,
electrical usage is not controlled during an off-peak
time. (The system will provide heat to satisfy
comfort requirements during this time as well as
charge or store heat in its brick core.)

On-peak ~ The time during the day or night when

the power company experiences a high demand for
electricity. To limit demand, certain appliances are
controlled to avoid usage by them and/or a premium
for the electricity consumed during this time may be
charged to discourage electrical usage. (The system
is not allowed to charge or store heat in its brick core
during peak periods. Heating requirements are
satisfied by only the heat it has stored in its brick
core.)

Outdoor Sensor ~ Device that senses outdoor air

temperatures and communicates this information to
the Comfort Plus for automatic charge control.

Location Value ~ The specific information set and

stored in a location on the microprocessor which
defines system operation. A value for a specific
location is accessed through the control panel.

Comfort Plus Appendix n A.16

Room Temperature Set Point ~ The targeted

room temperature the system is to maintain. If the
room thermostat senses a temperature below this
point, the heater's blower will come on and extract
heat from the brick core.

Appendix

W

Registering your purchase is an essential step to ensure warranty coverage. A Warranty Registration card
is included with the Owner's Manual. Simply complete, detach the bottom portion, and return the card
today. Retain the top portion of the card for your files.

WARRANTY STATEMENT

Steffes Corporation (“Steffes”) warrants that the Steffes ETS Electric Thermal Storage Heating Appliance is free from
defects in materials and workmanship under normal use and service. Steffes’ obligation under this Warranty is limited
to the repair or replacement of the appliance or parts only which prove to be defective under normal use within five
(5) years of the date of purchase, limited to seven (7) years from the date of manufacture, and which Steffes’
examination of the returned appliance or part(s) shall verify to Steffes’ satisfaction that it is defective. The user shall
be responsible for any labor costs associated with the repair or replacement of the appliance or part(s), including the
cost of returning the defective appliance or part(s) to Steffes Corporation.

This Warranty is void if the heating appliance is moved from the premises in which it was originally installed. This
Warranty shall not apply to an appliance or part which has been altered in any respect, or improperly installed, serviced
or used, or has been subject to accident, negligence, abuse or misuse.

Warranty

THE ABOVE WARRANTY BY STEFFES IS EXCLUSIVE AND IN LIEU OF ALL OTHER WARRAN­TIES, WHETHER WRITTEN OR ORAL, EXPRESS OR IMPLIED, INCLUDING ANY IMPLIED
WARRANTY OF MERCHANTABILITY OR OF FITNESS FOR A PARTICULAR PURPOSE.

The buyer assumes all risk and liability whatsoever resulting from the use of this heating appliance. In no event shall
Steffes be liable to purchaser for any indirect, special or consequential damages or lost profits.

This Limited Warranty contains the complete and exclusive statement of Steffes’ obligations with respect to the heating
appliance and any parts thereof. The provisions hereof may not be modified in any respect except in writing signed
by a duly authorized officer of Steffes.

Thank you for purchasing Steffes ETS heating equipment. We welcome your comments

relating to the Comfort Plus and this manual. Enjoy your new purchase!

3050 Hwy 22 North • Dickinson, ND 58601-9413• www.steffes.com

DOCUMENT #1200051