Electro Industries EM-WE1025H User manual

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WarmFlo Equipped
Electric Duct Heater
Size
H=8Wx10D
L=8Wx16D
EM-WE ** *5 * C = starter plenum
kW Stages
10 = 9.6 kW 2 = 2
15 = 14.4 kW 3 = 3
20 = 19.2 kW 4 = 4
Application – total electric systems.
-Air or water source heat pumps
-Air handler includes refrigerant coil, blower inlet
-No standby or gas furnace provisions
Utility load control – as a total electric application, we assume no utility control or switchover to
automatic standby. However, if this is not the case the electrical hookup section suggests wiring for load
control receiver connection. If installation also requires switchover to automatic standby furnace, call
factory for necessary furnace interface module (WF-EM3, WF-LGR3, or WF-EZ3).
To meet the above application, this WarmFlo system comes with a multi-coded chip. If factory default
does not match your application, reference HD320 for other setup parameters.

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TABLE OF CONTENTS
Page
Introduction 1
Specification 2
Mechanical Installation 3
Electrical Hookup 4
Controller Setup or Programming 6
Operation Indicators 8
Installation Checkout 9
Handheld Analyzer/Laptop Software 9
Troubleshooting 10
Operational Information 11
Drawings EI503-F1
EI503-F2
EI503-F3
HH310
HH332
ES502
HD320
XX017

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INTRODUCTION
Prior to installation we recommend that the installer verify the product intended application is
applicable to your current installation needs.
This product provides generic forced air electric resistance heater designed for air handler, heat pump, or
blower cabinet outlet duct installation. The relationship of the blower outlet to this insert heater must be
according to the specific mechanical installation or instruction in detail of this manual.
First-time or non-routine user – before attempting installation or setup, suggest studying the last section
of this manual, operational information and terminology definitions.
Basically the minimum airflow through the element rack is 100 CFM per KW (assumes 100°F inlet from
heat pump). Any air volume which passes around or outside of the element rack insert must be
discounted or added to the minimum 100 CFM per KW requirement. This manual provides the necessary
details for duct/plenum deflectors and/or duct heater element rack position in relationship to the blower
wheel to assure correct airflow through the elements.
NOTE: The maximum inlet air temperature is 100°F. For inlet temperatures greater than 100°,
contact the factory for special assistance.
This product is assembled complete with the WarmFlo II controller configured for a total electric
application as defined on the cover page. Various field or installation settings and decisions are required,
see the “Controller Setup” section.
For information, all units are rated at 240 volts AC. When operating at lower source voltage, the output
may be reduced.
Example: 9.6KW unit, assuming normal element tolerances
220 volt source – 8 kW
208 volt source - 7.3 kW
**Installation Notice** – the WarmFlo controller is designed to operate in conjunction with the
complete heating system – heat pump, strip heat, roomstat, WarmFlo sensors, etc. If one of these
components is missing or not initially installed, improper performance of the WarmFlo and the heating
system may be experienced. Suggest electrically this unit and the WarmFlo controller not be installed or
used until all the components of the heating system are in place and functional.
Warranty/Checkout – Attached to this manual is a warranty certification and checkout procedure. This
must be completed and returned for warranty coverage.
Failure to follow the mechanical installation details of this manual may shorten element life and may void
limited warranty provisions.

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INSTALLATION REQUIREMENTS
1. All installation work must be performed by trained, qualified contractors or technicians. Electro
Industries, Inc., sponsors installation and service schools to assist the installer. Visit our web site at
electromn.com for upcoming service schools.
2. All electrical wiring must be in accordance with national electric codes and local electric codes,
ordinances, and regulations.
3. Observe electric polarity and wiring colors. Failure to observe could cause electric shock and/or
damage to the equipment.
4. This unit can only be used for its intended design as described in this manual. Any internal wiring
changes, modifications to the circuit board, modifications or bypass of any controls, or installation
practices not according to the details of this manual will void the product warranty, the ARL
certification label, and manufacturer product liability. Electro Industries, Inc., cannot be held
responsible for field modifications, incorrect installation, and conditions which may bypass or
compromise the built-in safety features and controls.
SPECIFICATIONS - TABLE 1
Model Nominal
kW Current+ Min. CFM Element Cross Section Source CB Internal Fuse Shipping Weight
EM-WE1025H 9.6 40 1000 8 W x 10 D 50 N/A 12
EM-WE1535H 14.4 60 1500 8 W x 10 D 75 30 & 50 16
EM-WE2035H 19.2 80 2000 8 W x 10 D 100 50 & 50 19
EM-WE1025L 9.6 40 1000 8 W x 16 D 50 N/A 15
EM-WE1535L 14.4 60 1500 8 W x 16 D 75 30 & 50 19
EM-WE2035L 19.2 80 2000 8 W x 16 D 100 50 & 50 21
NOTE: Model series EM-WE****C is the same element and control box assembly as model EM-WE****L except
prepackaged in a 16”w x 16”d plenum.
* Assumes 100F inlet and all air passes through element rack. If duct/plenum is larger than element rack (without
factory deflector kit), the air volume external (passing around) to the element rack must be added to this CFM
requirement.
+ At 240 volt, single phase.

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MECHANICAL INSTALLATION
NOTE: When installing or mounting this duct heater within four feet of the blower outlet, the following steps
must be followed as detailed and shown in the appropriate drawing. This is necessary because the
airflow from the blower outlet, A-coil, T-Duct, elbows, etc., is very non-uniform. The elements
themselves must be centered over the blower opening width (wheel width) and the element rack must
be in line with the blower outlet outer edge, see Figure 2.
MODELS: EM-WE****H&L
Depending upon access and blower size, there are three possible insert locations. All reference is viewing the
blower wheel end as shown on Figure 3.
These blower arrangements are detailed and shown for UPFLOW and horizontal installations.
1. Blower End, Reference Figure 3 – only use model number last digit "H". As shown on the drawing, the
element rack right edge must line up with the blower outlet right edge. There shall be no opportunity for
air to pass by the element rack on the right. Basically the blower opening or plenum width (area to the
left of the element rack) is of little or no concern. All of the air coming off of the blower wheel is in the
first 4 to 6 inches on the outer scroll of the blower.
The control box back edge must line up with the blower opening edge. This is shown on Figure 3 with
the reference "in line". If the plenum section in which the Electro-Duct is inserted is larger than the
blower opening so that this "in line" cannot take place, do not use this method of installation.
If the plenum depth (area behind the elements) is larger than about 11 inches, a V deflector will be
required in the back of the plenum. See Figure 1 for examples of field constructed V deflector.
2. Insertion Over Blower, Reference Figure 2 – this is the preferred installation method if the blower width
(wheel width) is 8 to 10 inches for the "H" model or 14 to 16 inches for the "L" model. Of greater
concern is the opening depth (element rack length). The element rack must touch the back of the plenum
when inserted.
Again, if the plenum is larger than the blower opening, this method may not work without V deflectors as
shown on Figure 1.
3. Insertion from the Blower Back – this is opposite from Figure 2 where the control box edge would line up
with the blower back outlet edge. Also with this method, the elements are centered on the wheel width
and the hi-limit panel must be in line with the blower edge. Typically the blower opening depth (element
rack length) is of little concern because all the air coming off of the blower wheel is at the scroll outer
edge.
Plenums Larger Than Element Rack – whenever the plenum or duct is larger than the element rack, field
constructed or factory optional starter plenum is available or V deflectors are required to force the air through
the element rack. Figure 1 is to be considered an example. This internal deflector must be complete and
installed as shown. Do not simply use "an angled piece of tin". You must have the top section carried back to
the side of the plenum to prevent eddy currents. Basically the installer is simply providing an internal scoop
with the outer edge lined up with the bottom element. This will direct the air properly through the element rack.
NOTE: The airflow must be in the direction of the decal airflow.
MODEL: EM-WE****C
This model includes starter plenum. Position over the blower outlet with the blower discharge at the plenum
right (facing Electro-Duct control box). In other words, when facing the control box, you will also be looking
at the blower motor end.

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ELECTRICAL HOOKUP
High Voltage
240 VOLT SOURCE - Locate correct model number and KW size in Table 1 to determine operating current
and minimum source circuit breaker size. According to local codes, building type, wiring run distance, etc.,
use the appropriate electric conductor size for the 240-volt source power. Connect to fuse block/input
terminals (10KW is terminal block only).
GROUNDING - Route and install the appropriate size ground conductor between the ground lug labeled
"GROUND" and building service entrance panel ground bus. This must be a conductor sized according to the
total amp rating of the appropriate model. Conduit is not an adequate ground conductor.
Low Voltage
The WarmFlo controller within this strip heat product only operates the electric elements based upon the
thermostat Stage 1 call for heat and the outdoor/warm air temperature sensors. This WarmFlo controller has
no control over the heat pump, blower, room thermostat, or other parts of the heating system. In its simplest
form, consider this product as an “add-to” electrical connection.
Assumption – this manual does not attempt to define the heat pump manufacturer’s installation,
and assumes the heat pump is functional and has not been altered from the factory. Also, the
installing technician must have basic knowledge and understanding of heat pump control logic
and/or wire colors/functions. The basic heat pump installation, checkout, troubleshooting, repair of
its factory standard components is not covered in this manual.
WarmFlo II Sensors
Located within each WarmFlo control are two sensing probes, OT (outdoor sensing) and ST (supply
sensing) necessary for proper operation and installation of the WarmFlo systems. Without proper
installation of these probes the WarmFlo system will not operate correctly.
Outdoor Sensor (OT) is identified by the longer cable and the metal mounting bracket.
-Determine best location for the OT sensor using the following ground rules.
oLocate on the outside of the house to sample outside temperature least affected by sun.
oLocate sensor away from other objects that produce a heat or cool effect such as heat pump
Freon line sets, drier vents, and other miscellaneous objects that affect the air temperature.
oDo not install sensor in an enclosure which may have a “heat build up” or insulation effect.
-Disconnect OT and ST sensor cable from WarmFlo Controller noting the screw locations for future
re-hookup.
-The factory supplied OT cable is approximately 25’. Determine necessary length of cable to route to
the predetermined outside location. If the sensor wire cable is too short, you must use the following
rules for extending the cable.
oUse unshielded (low capacitance, prefer twisted) 3 or 4 wire low voltage cable, 35 foot
maximum.
oDo not under any circumstances use leftover wires within the thermostat cable going to the
outdoor unit.
oConsider approximately 50’ as the maximum total length.
-Mount OT sensor with sensor tip up (cable downward)
-Drill ¼” hole near the outside sensor location.
-Route wire from outside making sure not to crimp, cut, staple, or damage cable in any way.
-Keep the sensor cables at least 12” away from any line voltage wiring, Romex, etc. Do not, under
any circumstances, use part of existing thermostat cable, leftover wires, for the sensor cable.
-Do not reconnect sensor wires to the 4-screw terminal block until both sensors are properly installed.

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Warm Air Supply Sensor (ST)
-Locate the ST sensor directly above the electric elements. Requirement is about 24” above the
elements, approximately centered. If there is not 24” height before take-off ducts, locate in the major
distribution duct approximately 3” into distribution duct and approximately 2” from the top.
-Drill ½” hole for insertion of the ST sensor tube and the appropriate holes for sheet metal screw
mounting.
-Mount ST tube using two mounting holes.
OT & ST Sensor Reconnection
-A plug-in terminal block is provided for wiring convenience.
-Both red wires are terminated in the same single screw (+), and both white wires are terminated in
the single common screw (COM). Each appropriate black wire is terminated in the appropriate OT
and ST screw.
WARNING
IF THE BLACK AND RED SENSOR WIRES ARE CROSSED OR INCORRECTLY INSTALLED AT THE TERMINAL
BLOCK AND POWER IS TURNED ON, BURNOUT DAMAGE CAN RESULT WITHIN THE SENSOR PROBE.
WarmFlo Controller Thermostat Connections (reference hookup drawing HH310)
24-Volt Power Source – this controller will receive its operating power from the heat pump main and only 24-
volt transformer. This is the same as the “R and C” terminals between the roomstat and outdoor unit. Simply
tap the 24-volt transformer and route to WarmFlo controller upper right “R” and “C”.
Grounding – the installer must determine whether the heat pump 24-volt common has a good ground bond
(not simply air handled cabinet skin). If 24-volt common is not grounded, ground the “C” tab (in addition to
its normal hookup) for proper static ground protection.
Room thermostat first stage, Y – the roomstat yellow wire should go directly to the outdoor unit yellow.
This stays intact, but simply add or “tap” a connection from this yellow wire and route to the WarmFlo “Y”
tab. This is the basic “turn-on” or the connection which causes WarmFlo “to do its thing”.
Stage 2, typically W or W1 – WarmFlo does not incorporate a Stage 2 function, there is no termination or
connection for this wire. Nor is Stage 2 an optional pickup point for any other function related outside of the
WarmFlo control requirement. Simply leave this unterminated and unused.
Optional, emergency switch function – this wire can be connected to the WarmFlo controller left “E” tab.
This will override all temperature and WarmFlo controller logic functions. When energizing “E” all stages
come on to their full capacity.
CAUTION
Since WarmFlo is an “add-to” controller and since E terminal is a single wire from the stat simply being
energized, all other functions associated with blower, terminating the compressor, etc. when energizing
all electric elements must take place external to this controller.
Heat anticipator – the connection of the WarmFlo “Y” tab does not affect the roomstat heat anticipator
setting. The heat anticipator setting should remain as specified by the manufacturer’s instructions.
Utility load control – no direct provisions are made within this product for dual heat or normal utility load
management. In the normal WarmFlo dual heat arrangement load control happens within the furnace interface
module (fossil fuel kit). However, if there is a requirement to control this strip heat product (electric elements)
only, this can be accomplished with a simple connection. Also there is no provision in this product for
compressor load control.
Built-in compressor ODT – if using the built-in ODT function, there must be an added relay to open the
yellow wire going to the outside unit, dotted insert diagram on HH310. This must be a small, low current, 24-
volt DC relay as shown or order EE-5053 part from Electro Industries.

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CONTROLLER SETUP OR PROGRAMMING
Important - Located on the WF II board is a firmware chip that determines a specific set of defaults. This can
also be programmed (altered) with optional PC software (ET-SOFT-WF) or a plug-in WarmFlo analyzer (WF-
ANZ*). As part of the WF II system this chip represents critical defaults and settings that make your system
operate correctly.
This application, as outlined on the cover page, is supplied with “HPEL”. Other chip codes are available, or
can be field reprogrammed, see Handheld Analyzer section.
The factory default setup of the WarmFlo II module is detailed below:
Electric staging enable – Stage 1 = 50°F, 2 = 38°F, 3 = 36°F, 4 = 34°F
MU time – set as disable
ODT mode – HP ODT
SOT S time – disabled
SOT E time – disabled
OT sensor function – DT cal.
NOTE: If these factory defaults do not meet your application, reference HD320 for more options.
Dial Settings
Left dial switch – min. warm air – The yellow screwdriver adjustment dial sets a “floor” or level
minimum operating temperature. The supply temperature will never go below this point independent of
outdoor temperature. In other words, this is the flat horizontal line on the warm air versus outdoor
temperature curve. Reference later section “heat loss curve”.
0 = 90 4 = 98 Factory set on #3.
1 = 92 5 = 100
2 = 94 6 = 102
3 = 96 7 = 104
Right dial switch - built-in compressor ODT – The yellow screwdriver adjustment dial can be set to
terminate the heat pump (reference manual WF-ANZ*).
NOTE: Requires added relay to open yellow wire, see Electrical Hookup section.
The temperature settings related to the “ODT dial” are:
Ø = Disabled, no ODT switch-over Factory set on #3.
1 = -15F 5 = 10°F
2 = -10F 6 = 20F
3 = 0F 7 = 30°F
4 = 5F
COMMENT: If you are using outdoor compressor built-in ODT, set the dial to “0”.

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Center dial switch – temperature (efficiency dial) vs. outside – see later section “Heat Loss Curve”,
the numbers below set a duct or supply temperature point at 0° degree outside. This allows the installer
or user to determine the WarmFlo controller heat loss slope or how fast the supply temperature rises
based upon a decrease in outside temperature. The lower the selected value (flatter the heat loss curve)
the higher the operating efficiency (longer compressor run cycles). The higher the selected value, more
electric resistance is used to provide a higher comfort warmer air at the room register. If set on #7, the
elements will be full on at each thermostat heat call.
Ø = 100 4 = 122 Factory set on #2.
1 = 110 5 = 125
2 = 114 6 = 130
3 = 118 7 = Full EL
See Operational Information section for further explanation.

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OPERATION INDICATORS
WarmFlo II Controller
Strip Heat Disable – To maximize heat pump system energy efficiency and preventing “accidental”
unnecessary resistant strip heat when it is not required, this WarmFlo II controller disables or locks out
strip heat elements based upon outdoor temperature.
Stage 1 - 5ØF
Stage 2 - 38F
Stage 3 - 36F
Stage 4 - 34°
Monitor LED’s on WF II Controller
Green LED - When illuminated the WarmFlo II controller is receiving 24v power. Under all
normal operating modes, this should be solid green.
As a secondary function this green LED provides status of the two remote sensors. If a
sensor is inoperative, incorrectly wired, or malfunctioning; this monitor light is in a
blinking or pulsing mode. By checking the pulsing pattern, the appropriate sensor can
be identified.
OT sensor - 1ØØ ms blink every second.
ST sensor - two, 1ØØ ms blinks every second.
Both bad - ½ second on, ½ second off, alternating.
Amber LED – When illuminated the WarmFlo II controller is in the electric heat operating mode.
Red LED’s - The four red LED’s next to the output connector, indicate Stage 1, 2, 3, and 4
operation (Stage 1 is on the right).
Inside Relay Board Monitor Light
COMMENT: The relay board activates from the WarmFlo II controller as the WarmFlo II
controller interprets the “Y” input voltage in relationship to both temperature sensor
requirements. However, the “Y” input also directly controls the Stage 1 triac and the staging
relays. Whenever the “Y” input goes to 0 volts (at the end of the cycle) the relay output
immediately goes off and strip heat is turned off and not necessarily stepped down as shown
by the WarmFlo II monitor Red LED’s. This is a safety feature; strip heat cannot be on
accidentally by the WarmFlo II controller internal logic if there is no “Y” input.
Red LED - Illuminates when the low voltage hi-limit sensor probe (135°) opens. This applies
only after thermostat heat call and WarmFlo II controller is activating various element stages. If
there is a hi-limit condition, red LED is illuminated. As soon as the hi-limit cools and snaps back
in, red LED extinguishes.
Triac Relay Module (mounted next to relay board)
This module has its own built-in LED. When the LED is on, the triac switch is closed, elements will be
heating. This LED shall operate coincident with Stage 1 on the WarmFlo board.

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INSTALLATION CHECKOUT
Insert plenum thermometer 6” to 8” above the electric element section, position to measure the warm air
from the electric elements. Proceed with the following procedure, observing the various staging action,
element power current, and the outlet temperature.
-Verify controller setup dial switch settings per previous section. For this test, set the center dial
switch to #7. Return to previous setting at the end.
-For this test the ODT dial switch needs to be at 0 or #3. Again return to previous setting.
-Using WF Analyzer (or software) set the outside temperature (OT) to 5°F.
-Initiate thermostat call for heat:
oVerify heat pump is operational and producing heat, not cooling.
-Verify red LED’s are staging in, the system should go to all four stages.
-Verify electric element heating and plenum thermometer temperature is rising.
-With full heat output, wait 5 to 10 minutes to stabilize temperature and take the following
readings:
oPlenum temperature _______
o240 heating power, voltage _______
oMeasured 240 amps, current _______
oMeasured transformer control, voltage _______
-As you perform this test monitor the red LED on the relay board. This LED determines hi-limit
cycling. If the red LED came on and you observed hi-limit cycling, corrective action will be
required to make sure hi-limiting does not occur during normal operation.
oVerify all airflow is through the electric elements (proper baffling, electric element
positioning, etc.)
oIncrease airflow or determine ducting distribution problem loading the system.
oPerhaps it can be assumed full electric element heat is not required when the compressor
is running. If this is the decision, change the center dial switch to #4. If this improves
the air delivery situation, provide informational technique to make sure the user never
sets the center switch to #5, #6, or #7. If #4 still produced hi-limit, try #3. For proper
heating comfort #3 would probably be the lowest acceptable number. Again if you
cannot sustain non-hi-limiting operation with #3, a serious evaluation of the basic
airflow, blower, ducting system will be required to match your specific kW electric unit
sizing.
HANDHELD ANALYZER/LAPTOP SOFTWARE
This test tool and/or software is available for temperature offset, field altering the program chip
parameters and setup, and general assistance for troubleshooting.
See the enclosed “WarmFlo Information” document (HD320) for functional details.

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TROUBLESHOOTING
Comment: Also see the “WarmFlo Information” document (HD320) included with this manual.
Sensor Temperature Calibration - Both remote sensors are digital electronic and factory calibrated.
Normally these do not require field calibration or verification. However, if sensor temperature error is
determined, there are two field calibration techniques. Proceed with extreme caution.
-The outdoor sensor can be calibrated with ice (32F). This is not a temperature checking
situation. If you proceed with this function, the sensor automatically goes to 32°F. Notice a
small push button next to the sensor terminal block, with the sensor at 32°F, push and hold for
approximately ten seconds. When green LED “blinks” at you, release and now the outdoor
sensor is set at 32°F.
-Use WarmFlo II Analyzer test set or purchase special PC software disc and PC serial port cable.
These plug-in devices allow direct readout of both temperatures, allows a visual determination of
WarmFlo II internal temperature settings, and can be used to offset either temperature sensor for
troubleshooting and demonstration purposes. This is especially valuable during summer
installation. Call factory for either test set device
Troubleshooting/Repair Helps
-This WarmFlo II controller contains several interference suppression components, but as an electronic
logic product, unpredictable and unusual transients or interferences may sometimes cause strange results.
If the WarmFlo II controller is “acting strange”, one immediate step would be power down reset. Simply
turn off the 24-volt source power (probably furnace or air handler circuit breaker), when the green LED
goes out, count to 10, and re-energize power supply.
-The terminal blocks for control wire hook-up are designed for a wire insertion and screw clamp down. If
there is no wire connected and the screw is loose, the screw may not necessarily make a good electrical
contact to the inside components. Example – if you are jumpering the thermostat terminals without
thermostat wire connection or if you are attempting to measure voltage on the screw head, you may get
erroneous or unpredictable results if the screw is not tightened down.
-Use general heating system logic information and basic understanding of the terminal block wiring
functions when measuring voltage to determine proper operation of this module.
-The outdoor sensor must be located outdoors for this controller to correctly operate. Do not leave the
outdoor sensor “hang in conditioned space” and attempt to run this system.
-Acquiring the WarmFlo II Analyzer test set or the PC software and serial port hook-up cable (see previous
page) is a positive tool for understanding and troubleshooting the WarmFlo II controller. Either test set
device can display all temperatures, real time evaluation of WarmFlo II functions, provide temperature
offsets for assimilating winter conditions, and reprogram the control chip (program stays with the actual
WarmFlo circuit board, not with the plug-in chip).
Bad sensor, safety – if the internal logic detects open sensor wire, incorrectly wired sensor, or some bad
sensor transmitted value conditions; the green LED reverts to a pulsing mode. Basically the appropriate
sensor is set internally to a 0° value and there will be an attempt to cause the electric heat output to go
“DT flat”.
-OT sensor – approximately 1/10 second blip every ½ second
-ST sensor – two, 1/10 second blips every ½ second
-Both bad – ½ second on and ½ second off, alternating

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OPERATIONAL INFORMATION
In order for the installer to completely understand the WF II functions and operational sequence it is
recommended to thoroughly read and understand the information below. This knowledge can help in
determining settings that can be set according to the end customers needs.
Normal Heating Operation – Whenever the WarmFlo II Y tab is at 24 volt (with reference to “C”), the
WarmFlo II controller begins turning on the Electro-Mate elements (assume outdoor temp. is below disable
value) and automatically controls the warm air temperature as sampled by the warm air sensor (ST). However,
if added heat is not required, no element power is used.
Depending upon Electro-Mate model, the heating section may have one, two, three, or four stages. Stage
1 is pulse modulated (approximate 10-second cycle) based upon the WarmFlo II controller automatic
requirement. Stages 2, 3, and 4 are turned on and off with a relay. However, Stage 2 is only used when
needed by the WarmFlo II supply air temperature calculations. When the warm air sensor is calling for
more than the heat pump and Stage 1 100% output, Stage 2 turns on. Stage 1 may not necessarily remain
at 100%, but is modulated downward to meet the requirements of the warm air sensor.
Also on the next call for heat, the WarmFlo II controller remembers what stages were on and starts at that
point. A clamp-on amp meter at the service input can be used to “visualize” the Stage 1 modulation
and/or Stages 2, 3, and 4 functions.
Efficiency – the characteristic of a heat pump dual heat system is the heat pump’s ability to deliver warm
air at efficiencies greater than 100%. Gas and oil systems are always less than 100% (60% through 90%),
resistance electric (Electro-Mate) is always exactly 100%, but the heat pump is always at least 100% (-
20°F) or greater, up to about 200% for air source.
Realizing it is to the user’s advantage to run the heat pump either continuously or at the longest possible
thermostat call cycles. This is contrary to the basic understanding of most users. However, realizing
again the heat pump is a device that delivers greater than 100%, this system can only deliver greater than
100% if it’s running, let it run. Because of the WarmFlo design concept and its internal “brain” the heat
loss curve (diagonal lines, above) allows the compressor to operate with a minimal amount of electric
resistance supplement or temperature boost.
Where should I set the efficiency (center) dial? – As you can visualize from the heat loss curve (Figure
1), the lower the setting, the flatter the curve, the less electric resistance is added to the heat pump
compressor warm air. Therefore, the efficiency knob setting is based upon comfort and efficiency. The
lower the setting the higher the overall operating annual efficiency, the higher the setting the warmer the
air at the register.
Heat loss curve – within the “brain” of the WarmFlo controller is a relationship of supply temperature to
outdoor temperature measurement. As it gets colder outside, the higher the supply temperature in order to
properly overcome the heat loss within the structure. This is the diagonal line between 65° outdoor and
maximum Btu/h (heat loss) at the coldest outdoor temperature. The slope of this line or the exact warm
air position at the coldest temperature is established by the “efficiency” adjustment knob or dial.

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Figure 1
Factory set per table and chip on order sheet.
Outdoor sensor reference or heating requirement level – the outdoor digital sensor “tells” the
WarmFlo “brain” its desired (DT) value or decision making capability. This is for desired or required
supply temperatures greater than the “min. warm air” horizontal line setting. At each internal calculation
cycle a DT is determined by reading the outdoor temperature and then finding the appropriate warm air
point on the appropriate or selected diagonal line. See Figure 1 for the various diagonal lines associated
with the A through G “temperature” selection knob.
Example – if the temperature knob is set on Position C, at 20° outside the DT or the supply
delivery temperature is 100°. The WarmFlo controller now automatically adjusts and maintains
electric element power to keep the supply temperature at 100°. Likewise if it -10° outside the DT
or supply delivery temperature is 120°. The elements are re-adjusted to provide a constant 120°
temperature.
Chip code/field programming – your unit was supplied with a “multi-coded” program chip, one of the
selections shown in each Chip Code Reference Table for your application. These tables show the various
defaults associated with that particular code. With WarmFlo II version a number of field re-programming
possibilities and options exist using either PC software or WarmFlo analyzer, reference “WarmFlo Handheld
Analyzer/Laptop Software” section. Chip code is located on the WarmFlo II controller board white label.
Note: There are certain things such as SOT’s, MU time, etc. which are only field programmable. If
the item is not shown in the chip code table, that feature or item is default set as disable.
Delay, transfer from standby to electric – if the unit was operating in SB for more than 1 minute, the
follow-up transfer back to electric engages a 2-minute delay before the HP compressor relay is activated
and any of the electric stages are activated. The blower will react to the call for heat, but the elements
will stay off for 2 minutes in order for the blower to cool down the furnace heat exchanger.

Must include upper
metal section
90-degree angle
Observe heater
air flow label
Element rack
Notes:
1. Center heater elements
over blower outlet.
2.To maintain warranty,
deflectors must be installed
as shown.
IMPORTANT NOTE:When mounting Duct Heater
within four (4) feet of blower and plenum is larger
than blower opening, you MUST follow this drawing
in detail!
AIRFLOW
BLOWER
MEF
-
-
4383
RELEASED
1:1
07-16-02 1/1
DECAL LAYOUT -
EI503-F1
DUCT HEATER
LARGE PLENUM
APPROVED DOCUMENT DATE SHEET DOCUMENT NUMBERDRAWING STATUS
CHECKED VIEW/DRAWING TYPE SCALE PART/ASSY/MODEL NUMBER
SOURCE DOCUMENTDRAWN
MONTICELLO, MN 55362
ELECTRO INDUSTRIES, INC. DESCRIPTION
UAI937
INTERNAL COMPONENTS
REQUIRE MOUNTING
UPRIGHT

MEF
-
-
4384
RELEASED
1:1
07-24-02 1/1
DECAL LAYOUT -
EI503-F2
DUCT HEATER
MECHANICAL INSTALLATION - FRONT
APPROVED DOCUMENT DATE SHEET DOCUMENT NUMBERDRAWING STATUS
CHECKED VIEW/DRAWING TYPE SCALE PART/ASSY/MODEL NUMBER
SOURCE DOCUMENTDRAWN
MONTICELLO, MN 55362
ELECTRO INDUSTRIES, INC. DESCRIPTION
Element rack
Notes:
1. Blower width range is 8" to 10". If larger
than 10", must use side "V" deflectors.
2. If the plenum/duct is wider than blower
opening, must use side "V" deflector, call
factory for assistance.
3. If smaller than 10", plenum can
center over blower outlet. Cannot
be larger than 10"
4. Max depth is 10". DO NOT use
this insertion method unless
element rack completely fills
plenum.
IMPORTANT NOTE:When mounting Duct Heater
within four (4) feet of blower and plenum is larger
than blower opening, you MUST follow this drawing
in detail!
AIRFLOW
BLOWER
3
1
42
8-10"
10"
MAX.
UAI937
INTERNAL COMPONENTS
REQUIRE MOUNTING
UPRIGHT
Observe heater
air flow label

MEF
-
-
4385
RELEASED
1:1
07-24-02 1/1
DECAL LAYOUT -
EI503-F3
DUCT HEATER
MECHANICAL INSTALLATION - SIDE
APPROVED DOCUMENT DATE SHEET DOCUMENT NUMBERDRAWING STATUS
CHECKED VIEW/DRAWING TYPE SCALE PART/ASSY/MODEL NUMBER
SOURCE DOCUMENTDRAWN
MONTICELLO, MN 55362
ELECTRO INDUSTRIES, INC. DESCRIPTION
Element rack
IMPORTANT NOTE:When mounting Duct Heater
within four (4) feet of blower and plenum is larger
than blower opening, you MUST follow this drawing
in detail!
AIRFLOW
BLOWER
Direction of elements must
match blower position shown
FOR PROPER AIR FLOW:
Right edge of element
duct heat heater MUST line
up with right edge of blower
UAI937
INTERNAL COMPONENTS
REQUIRE MOUNTING
UPRIGHT
Observe heater
air flow label

E L E C T R O I N D U S T R I E S , I N C .
M ON T I C E LL O , M N 55362
W A R M F L O SYS T E M
H P W / E M - W E
HH 310
R EV . G 03 - 07 - 07
NO T E S :
1 . P E R H P M F G . HOO K - U P
2 . S I N G L E C ON T R O L L I N E .
3 . 3 - W I R E C A B L E ( E A C H ) , PR O V I D E D .
4 . I F F U LL E L E C T R I C I S D E S I R E D , C ONN E C T T O " E " T A B .
5 . H P O D T , 2 C HO I C E S :
- U S E M F G . PR O V I D E D W I T H I N OU T D OO R UN I T
- U S E W A R M F L O S E N S O R & C ON T R O LL E R , A DD R E L AY ( S EE
D
E T A I L S A , B )
H P
C
O I L
B L O W E R
E M - W E S E R I E S
D U C T H E A T E R
P
A CK A G E
T 5
T E M P E R A T U R E
A 1
E L ON
L E D 6
U PCB 56 1 5
C S
M I N I M U M
W
A R M
A I R
S W 1
L E D 3 L E D 4 L E D 2 L E D 1
J1
S W 4
C A L .
O D T
S W 3
C O M
R E D
T
B
1
O T
S T
H P - O D T
J 3
J 2
L E D 5
T 4
C
T 6
T 1
T 2
E
Y
T 3
R
S W 2
L E D 6
E L ON
T E M P E R A T U R E
S W 5
W A R M A I R
D E T A I L A
S C A L E 4 : 1
C A L .
S W 4
E
T 6
C O M
O T
R E D
S T
T
B
1
T 4
C
T 1
T 2
Y
T 3
R
D U C T
OU T S I D E
R
E
D
W
H
T
B
L
K
W H T
R E D
B
L K
H P - O D T
E
H P O D T
S EE D E T A I L B
2 N D S T A G E
B L O W E R
E M E RG E N C Y
GR EE N
S EE M A NU A L
( D O NO T U S E )
1
4
( D O NO T U S E )
D E F R O S T
2
24 VA C HO T
24 VA C C O MM ON
R E V E R S I N G VA L V E
1S T S T A G E
R OO M T H E R M O S T A T
R E D
B L U E
Y E LL O W
O R A N G E
OU T D OO R UN I T
1
R
C
Y
O
O D T
5
3
B L K / Y E L
GR AY
24 V DC O R
24 VA C
B L U/ Y E L
O RG / B L K
Y E L / GR N
R
H P - O D T
EE - 5053
5
5
D E T A I L B
E M - W E
( C ON T R O L B O A RD )
Y
Y