WarmFlo HE-A-**-21 Series, HE-A-10-21, HE-A-15-21, HE-A-20-21 Installation & Operating Instructions Manual

WarmFlo® Electric Furnace

Installation & Operating Instructions

HE-A-**-21 Series

All HE-A-**-21 Electric Furnaces must use one of two chip codes based on applications

 An AHS chip code: forced air space heating applications
 WFMU chip code: make-up air applications.

If you have a chip code other than AHS or WFMU, please call factory for assistance.

Application
Forced Air Space Heating:

This model series is outlet warm air sensing only for non-heat pump applications. With a preset warm air
temperature, the electric elements modulate to maintain this preset temperature based on the sensing of
the supply sensor (ST). The CFM requirement will always have to be setup for full electric capacity.

Heat/cool conventional room thermostat applies

Make-Up Air Heating:

Fresh air code requirements and/or appliances which could
create unhealthy negative pressure within the building.

 Building usage, people loading
 Air environment within building
 Fireplace
 Larger kitchen vent hoods
 Appliances, without sealed combustion
 Single vent gas furnace or water heater
 Forced exhaust systems - restrooms, bathrooms,

kitchens, etc.

DO NOT DESTROY THIS MANUAL. PLEASE READ CAREFULLY AND KEEP IN A SAFE

PLACE FOR FUTURE REFERENCE BY A SERVICE TECHNICIAN.

Drawings:

NH806, NH807, NH819, NS802, EC001, XX017

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Table of Contents

Configurator 1

Inlet Cabinets 2

General Comments 3

Application 4

Installation Requirements 6

Mechanical Installation 7

Electrical Installation 9

Setup or Programming 11

Operation Indicators 12

Handheld Analyzer/Laptop Software 13

Troubleshooting 13

Replacement Parts 15

Drawings Included:

NH806
NH807

NS802
EC001

XX017

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Configurator

HE-T-KW-CW

Type Cabinet Width
H, A, E, N 21 = 21”
(see below) 24 = 24”*

kW Size
10 = 9.6 kW
15 = 14.4 kW
20 = 19.2 kW*
25 = 24 kW*
30 = 28.8 kW*

Type

All models – ECM™ blower motor, setup selection of four cooling sizes, 50% continuous air (fan – on

setting). High efficient air circulation at about 50-watt.

H = Full WarmFlo capability with outdoor sensor. This provides warm air outlet temperature dial

selection and supply air ramp up with the decrease of outdoor temperature. This WarmFlo
feature definitely applies to heat pumps, but it is also the top of the line comfort for straight
electric, with air conditioning. The warm air dial suggested setting is 96° or 100° and the front
dial selects the rate of ramp up or temperature increase based upon outdoor. The “C” setting
will provide 114° warm air at 0° or 125° at -20° F outside. The ECM™ blower also ramps up
in speed as there is an increase in supply temperature or decrease in outdoor temperature.
Depending upon setup selection, the moderate heating blower speed could be as low as 60% of
full capacity and full capacity blower is only used below 30° outdoor.

 Heat/cool conventional thermostat must be used in non-heat pump applications
 Basic heat pump room thermostat must be used in all heat pump applications.

A = WarmFlo element modulation based upon a warm air set point and duct sensor. Heating blower

speed is installation setup per kW size. A higher CFM selection can be made if there is a desire
to “work” WarmFlo harder.

Heat/cool conventional thermostat applies.

E = Non-WarmFlo, 10, 15, or 20 kW built-in strip heat, direct function of roomstat W. Setup

selection determines nominal ECM™ motor speed. A thermostat “E” type function could be
used to jump to full speed.

N = Cabinet only, no electric elements or WarmFlo. This could typically be associated with an inlet

hydronics water coil. Control board includes a relay for pump, initiated with input W. Setup
selection determines heating blower speed. Cooling speeds and air conditioning interface are
the same as mentioned above.

Note: Two-speed and multi-function room thermostat can also be configured with this system by adding

WF-HP2 interface controller.

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Inlet Cabinets

Factory optional cabinets can be configured with this Electric Furnace. Typically these are designed for
upflow applications; however, the heat pump coil cabinet could be used in other positions.

Side Entry, Filter Cabinet

Return air can be ducted into either side, 15-⅜” x
19” cutout hole is provided with one filler plate.
Easy access door for checking and changing filter.

Adjustable rails are provided for standard 4” x 20”
x 20” pleated filter.

Filter examples include Honeywell 203721, BestAir
HW2020, or Grainger

Standard 1” filter (20” x 20”) – field installer could arrive at filter filler bracket for slip-in within the
provided rails.

Comment – The 3M MERV filter airflow resistance needs to be considered in duct design

calculations. Per specification information from 3M the static pressure drop across the 1”, Series
1000, MERV 11 filter is 0.2” SP.

Hydronics Coil and Cabinet

The inlet cabinet includes a water coil with
parameters shown. The return air connection must
be on a side which allows coil draw-through. The
cabinet can be reversed for either left or right side
entry. The inlet for this cabinet is sized for an
externally installed packaged return air filter cabinet
– typical 20” x 20” size.

1. Nominal or rated Btu/h, 50,000

2. Recommended CFM setup, 1100 min.

3. Inlet water 120° at 10 GPM minimum.

4. Expected outlet air temperature, 115°

Reduced CFM and/or inlet water temperature will
reduce Btu/h rating.

®

6B936.

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General Comments

Upflow/Downflow/Horizontal

The arrangement of refrigerant coil, hydronics coil, and built-in electric elements need to follow specific
air direction or airflow rules, but the orientation of this Electric Furnace is not critical.

For upflow and horizontal standard air conditioning applications; the A-coil is mounted at the blower

outlet with field provided plenum or AC manufacturer’s case coil.

All models contain GE ECM™ Series 2.3 blower motors. The special Electro Industries interface board
allows hookup for heat/cool conventional or basic heat pump room thermostat. Blower speed setup and
WarmFlo sensor control are separate for cooling and heating (unique).

The ECM™ motor provided in this unit has many features not available in a standard motor.

- Improved efficiency

- Constant CFM

- Soft start and stop

- Better humidity control

The provided ECM™ motor contains permanently sealed bearings and does not require oiling.

Utility Load Control

Provisions are included for the Utility Receiver to interrupt compressor and WarmFlo or strip heat. No
provisions for dual heat, add EE-5046.

Zone Controller/Dampers

When using models HE-A or HE-H Series there are no adverse electrical heat concerns associated with a
zone damper system. However, there may be an effect on the heat pump compressor due to potential
reduced airflow. The zone dampers themselves must be in the horizontal ducts after the WarmFlo duct
sensor and at least 12” downstream of the WarmFlo sensor.

The zone controller “HVAC equipment” terminal block simply connects to this unit’s control board as if
it was a room thermostat to this unit. If the various zone sizes produce high static pressure and reduced
airflow, the WarmFlo temperature sensing technology will reduce the electric elements automatically.

If the zone damper action has an adverse effect on the heat pump compressor, Electro has zone controller
staging interface for 2-speed heat pump application (WF-HP2, etc.).

Side by Side, with Gas Furnace or Other Dual Heat Arrangements

Add-on dual heat controller HP-5046 can simplify the wiring for dual heat.

For side by side ducting, a motor operated damper is required to isolate the return air between two
blowers. The operation of this motor damper can be controlled from the HP-5046.

Installation Setup

There are specific peg jumpers relating to cooling tons, heating kW, heat pump reversing valve logic, and

thermostat type. These must be properly evaluated and selected to match each installation.

The “setup or programming” section has all the detailed instructions and selection tables.

The WarmFlo controller also has various dial switch selections relating to duct temperature set point,
minimum warm air set point, HP compressor ODT shutoff temperature, and ramp up efficiency dial.
These are standard WarmFlo technology and setup requirements, if you’re not familiar with WarmFlo
controller study the HD320 WarmFlo information document, also in this package.

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NOTICE: When changing any setup jumpers, power down and up. ECM™ motor needs 240V power
and control power removed to reset and reread specific control lines. Open CB number 1 for 10 seconds.

Operation Instructions

The “Operation Indicators” section contains information relating to LED monitor lights, thermostat
sequences, etc.

Installation Checkout

Attached to this manual is a warranty certification and checkout procedure. This must be completed and
returned for warranty coverage. This is the responsibility of the contractor or company which “sold the
job” and is assuming responsibility to the end customer.

Warranty Statement

See the last page of this manual for detailed limited warranty coverage explanation.

Application

General

The configurator, previous page, details several product types. Re-verify nameplate on your received unit
to make sure it properly represents the product type you need for your installation/application.

The setup control board jumpers provide ECM™ blower motor speed flexibility to match the model and
your heat/cool size requirements.

This specific model series, HE-A-**-**

This model series is outlet warm air sensing only. With a preset warm air temperature, the electric
elements modulate to maintain this preset temperature based on the sensing of the supply sensor (ST).
The CFM requirement will always have to be setup for full electric capacity.

Make-Up Air Applications

Located on the WarmFlo board (logic controller) is a 40-pin microcontroller chip. On this chip is a white
sticker which indicates chip version (V2.3*) and chip code. This correct chip code for make-up air

applications is WFMU which has a specific temperature range options for make-up air applications.

Backup or Assist Wood Heating

This WarmFlo Electric Furnace is ideal for accompanying a wood heating system. The WarmFlo
technology and sensors will determine the Btu/h heating requirement of the building. If the wood warm
air is below the requirement, a small portion (or as required) of the electric elements will come on
automatically supplementing the wood heat.

Using a wood boiler with the water coil inlet option is an ideal arrangement.

If using a forced wood system, caution must be used when allowing the wood warm air to enter through
the ECM™ motor blower. The maximum temperature for the ECM™ motor is approximately 120° F.

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Specification Chart

Model Number HE-A-10-21 HE-A-15-21 HE-A-20-21

Cabinet Width 21” 21” 21”
kW rating 10 15 20
Btu/h 34000 51000 68000
Voltage/Phase 240/1 240/1 240/1
Circuit Breaker 60 1-60, 1-30 2-60
Amps per CB 42 42, 21 42, 42
Source Feed 1 2 2
Elements 4 6 8
Relays 2 4 6
Heat CFM* 765 (LO) 900 (M) 1035 (HI)
Max. Temp. Rise 45° F 45° F 45° F
Shipping Weight

*WarmFlo sensing will override this to 1200 CFM.

Product Dimensions

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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.

WARNING

ALL ELECTRICAL WIRING MUST BE IN ACCORDANCE WITH NATIONAL ELECTRIC CODE
AND LOCAL ELECTRIC CODES, ORDINANCES, AND REGULATIONS.

WARNING

OBSERVE ELECTRIC POLARITY AND WIRING COLORS. FAILURE TO OBSERVE COULD
CAUSE ELECTRIC SHOCK AND/OR DAMAGE TO THE EQUIPMENT.

CAUTION

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 CSA/us certification label, and manufacturer product liability. Electro Industries, Inc.,
cannot be held responsible for field modifications, incorrect installations, and conditions which
may bypass or compromise the built-in safety features and controls.

2. If this is a Dual Heat system, this product relates only to the addition to the furnace ducting system

external to the gas or oil force air furnace. The owner/ installer assumes all responsibility and/or
liability associated with any needed installation of the gas/oil furnace, fuel system, flue, chimney, etc.
Any instructions or comments made within this manual (or factory phone assistance) relating to the
gas/oil furnace are provided as comments of assistance and “helps” only.

CAUTION

This unit shall not be operated (either heating section or blower) until the interior of the
structure is completed and cleaned. This also means all duct work must be complete with
filter, etc. Both manufacturers’ warranties are void if this unit is operated during structure
construction.

CAUTION

Hazards or unsafe practices could result in property damage, product damage, severe personal
injury and/or death.

3. Remember, safety is the installer’s responsibility and the installer must know this product well

enough to instruct the end user on its safe use.

Safety is a matter of common sense - - a matter of thinking before acting. Professional installers have
training and experienced practices for handling electrical, sheet metal, and material handling
processes. Use them.

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Mechanical Installation

Clearances and Accessibility

Zero clearance is allowed on all sides for combustible materials. However, 36” should be allowed at the
front for operation, maintenance, and service.

To reduce the risk of rusting and appearance, do not install the unit directly on the ground or on a floor
that is likely to be wet. In such environments the unit must be elevated by use of a sturdy non-porous
material.

General Ductwork and Airflow Requirement

Design the airflow ductwork to meet the maximum operating airflow (CFM) for the kW and cooling ton

requirements (whichever is larger). This document does not provide installation and design information
for the ductwork external to this product. It is assumed this is being accomplished by a professional and
trained installer understanding ductwork design, airflow/static pressure resistance, and forced air
distribution systems. Key requirements information:

- Heating and cooling blower speed or minimum CFM is setup independently. See the “Blower

Speed Selection” to match the airflow capacity with the ducting design.

- The airflow distribution system shall be designed for a maximum of 0.5” SP. Ideally the design

should be set at 0.3” to 0.4” SP.

- The variable speed, ECM™ motor, is sensitive to inlet static pressure. In order for the motor to

arrive at the setup CFM (motor RPM adjust according to static pressure) the inlet must have a
minimum resistance of about 0.15 to 0.2. If you do not have return air ducting and you’re simply
allowing free return air circulation through a filter at this Electric Furnace inlet, you may need to
have a slight restriction in order for the blower motor to arrive at its setup speed.

- All transitions must have a slope of 30° to 45°. There shall be no 90° bends or surfaces causing

airflow bounce/eddy current.

- The manufacturer strongly recommends the return air entering the bottom (under the blower) of

the cabinet. For smaller kW and smaller cooling (10 kW or 2-ton) it is permissible to bring the
air in on either side of the 32” cabinet.

- Previous Specification Chart shows the minimum CFM associated with the kW. Again this is

setup as detailed in the “Setup or Programming” section.

- The cooling CFM is also selected but is not shown on the Specification Chart. In many cases the

airflow distribution system is probably designed to meet the cooling requirement.

- The room registers and individual 5” or 6 “ runs must also match the total setup or planned CFM

for this installation. Typically a 6” round and a typical room register is rated at 100 CFM.

- All distribution ducts (supply and return) must be sized for the setup or planned total CFM

requirement. The attached duct sizing chart shows various distribution duct sizes relating to their
ability to properly handle the stated CFM.

- Seal connections between this unit and ductwork, all ductwork connections, etc. as required to

reduce or eliminate air leakage. Sealing all connections will also reduce air noise.

Comment: The ECM™ motor efficiently relates to system static pressure. On one hand a minimum of

about 0.2” SP is required for the motor to adjust itself, but above 0.3” it begins to drain high current. For
information, consider (at 240):

1.0” SP – 3.4A

0.8” SP – 2.5A

0.5” SP – 0.9A

0.2” SP – 0.4A
Continuous Air – 0.25A

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