heatco EF Series Instruction manual

INSTALLATION, OPERATION
& MAINTENANCE MANUAL
ANSI Z83.8 (2016) – CSA 2.6(2016) – GAS-FIRED DUCT FURNACES
This manual must be kept with the appliance for future reference.
EF-IOM-MAN-E-2016-2
EF SERIES DUCT FURNACE

2
The information provided in this manual applies only to the duct furnace, its installation in duct work
or air handler cabinet and to its operation, maintenance, and service. Refer to the air handling unit
manufacturer’s instructions for information related to all other components.
Table of Contents
I. Inspection on Arrival 3
II. Safety Rules 3
III. Installation Requirements 4
Furnace Location 4
Duct Furnace Installation 5
Clearance to Combustibles 5
Airflow Distribution 5
Combustion Air Supply 6
Condensate Drain Lines 6, 7
IV. Venting 8
Outdoor Installation 8
Indoor Installation 9, 10
Separated Combustion 10, 11, 12, 13
V. Gas Supply Piping 14, 15
VI. Electrical Requirements 16
Wiring Diagrams 16, 17
Electrical Ratings 17
Installer Safety 18
VII. Initial Start-up & Adjustment 18
Start-up 18, 19
Shutdown 19
VIII. Normal Operation 20
IX. Duct Furnace & Burner Inspection 20
Periodic Inspection 20
Annual Maintenance & Inspection 20

3
I. Inspection on Arrival
Inspect unit on arrival. Report any damage to the transportation company and unit manufacturer. Inspect skids and
cartons for signs of poor handling that may have caused damage. If unit is stored prior to installation, make sure unit
is protected from rain and snow and stored in a low traffic area.
II. Safety Rules and Precautions
The installation, operation and maintenance instructions in this manual must be followed to
provide safe and efficient operation of the furnace. Care must be exercised regarding special
precautions noted throughout this manual. Failure to address critical areas and situations noted
could result in PROPERTY DAMAGE OR LOSS, PERSONAL INJURY, OR DEATH.
HAZARD INTENSITY LEVELS
1. DANGER: Indicates an imminently hazardous situation, which, if not avoided, will result in death or
serious injury
2. WARNING: indicates a potentially hazardous situation, which, if not avoided, could result in death or
serious injury
3. CAUTION: indicates a potentially hazardous situation, which, if not avoided, may result in personal injury.
It is also used to alert to unsafe practices and hazards involving possible property damage.
4. IMPORTANT: Indicates a situation which, if not avoided, may result in a potential safety concern.
Before Installing
1.) Verify that available gas supply, inlet gas pressure, airflow and electrical supply match information on furnace
rating plate.
2.) The furnace is not to be used for temporary heating of buildings or structures under construction.
3.) Do not use furnace if any part has been under water. Contact a Qualified Service Agency to inspect the furnace
and replace all gas and electronic controls that have been wet.
DANGER
!
Gas-fired furnaces are not designed for use in hazardous atmospheres
containing flammable vapors or combustible dust, in atmospheres containing
chlorinated or halogenated hydrocarbons, or in applications with airborne
substances containing silicone.
WARNING !
This furnace is not listed or suitable for drying or process applications. Use in
such applications voids any warranty and manufacturer disclaims any
respo
nsibil
i
t
y for the duc
t
furn
ace and /
or application
.
Duct furnaces must not be installed where flammable vapors are present or where
potentially explosive atmospheres may exist. To prevent premature heat exchanger
failure do not locate unit in corrosive atmospheres or where chlorinated,
halogenated hydrocarbons or acid vapors are present.
WARNING !

4
III. Installation Requirements
All unit installations must be in accordance with the National Fuel Gas Code ANSI Z223.1 (NFPA 54) in
the United States and Can/CGA-B149 Installation Code in Canada, and all other applicable local codes
and ordinances. These requirements include but are not limited to:
Furnace Location and clearances
Circulating airflow and ductwork
Combustion air supply to the heating equipment
Venting of the products of combustion (flue gases)
Gas supply, piping and connections
Furnace Location
1. When locating the duct furnace, consider general space and heating requirements, availability of gas and
electrical supply, and proximity to flue exhaust vent locations and condensate drain lines.
2. Do not install duct furnace vent where flue products can be drawn into adjacent building openings such as
windows, doors or fresh air intakes.
3. Equipment access panels and doors must be located to provide easy access for servicing, adjustment and
maintenance of the heating units installed.
For Outdoor Units
1. Unit must be installed with combustion air openings located at least 18 inches (0.45m) above the average snow
depth for the location.
2. Combustion air inlet and flue gas outlet must be located in the same pressure zone to minimize effects of wind
on burner and heater performance.
3. Do not locate unit near building ventilators or exhausts, or areas where corrosive chemical vapors can be drawn
into combustion air supply.
4. Be sure that vent discharge for flue gases is directed away from combustion air inlet and located to prevent flue
products from being drawn into combustion air supply.
For Indoor Units
1. Indoor installations use building air for combustion air supply and vent the products of combustion outdoors
through a single wall or roof penetration.
2. Locate unit to ensure an adequate supply of fresh air to replace air used for combustion and ventilation process.
3. If necessary, to ensure suitable combustion air supply to unit, provide air openings equal to one square inch of
free area per 1000 Btuh of input rating.
4. When locating units, it is important to consider the exhaust vent piping must be connected to the outside
atmosphere. See table below for required minimum clearances from vent termination. Location should minimize
the number of elbows or turns in vent pipe.
Structure Min. Clearances to Vent Terminal
(all directions unless specified)
Combustion air inlet of another appliance 6 ft. (1.8m)
Forced air inlet within 10 ft. (3.1m) 3 ft. (0.9m) above
Door, window or gravity air inlet
4ft. (1.2m) horizontally
4 ft. (1.2m) below
1ft. (0.3m) above
Gas meter and relief equipment, Electric meter US- 4ft. (1.2m) horizontally
Canada - 6 ft. (1.8m)
Gas Regulator 3 ft. (0.9m) horizontally
Adjacent public walkways 7 ft. (2.1m) above

5
Duct Furnace Installation
For a duct furnace connected to a return air duct or mounted in a cabinet, furnace shall be installed on the positive
pressure side of the circulating air fan. Furnace can be configured for horizontal airflow only, as shown in Fig. 1
Figure 1 – Airflow Configurations
With return air duct, furnace shall be installed with inlet duct that provides air distribution equivalent to a straight run
of duct having the same cross-sectional area as the inlet connection and not less than two (2) equivalent duct
diameters in length.
Ductwork should be mechanically fastened to heating unit. Joints should be sealed with high temperature silicone
caulking or high temperature tape to prevent leakage of circulating air. All duct connections MUST be weather tight
to prevent rain and snow from entering ductwork. Support all ductwork securely. DO NOT rely solely on heating unit
duct connections for support.
Provide removable access panels in ductwork immediately upstream and downstream of duct furnace to allow for
inspection of the heat exchanger. These openings should be large enough to observe smoke or reflected light inside
the casing to inspect heat exchanger for leaks, and to check for hot spots on the heat exchanger due to poor air
distribution or insufficient air volume. Attach covers so as to prevent air leakage.
Clearances to Combustibles
Duct furnace is for installation on non-combustible floor or base. Provide suitable clearances to
combustible construction as follows:
Sides / back: 6 inches (152mm) Top: 6 in. (152mm) Front: 36 in. (635mm) Vent Pipe: 2” (50mm)
For applications where unit is to be mounted above combustible flooring, an insulated cabinet base must be
specified. Clearance above combustible flooring is 2 in. (50mm), with this base.
Airflow Distribution
Uniform air distribution over the heat exchanger is essential to proper operation and optimum unit efficiency. Use of
baffles and/or turning vanes may be required to provide uniform air flow though the heating unit. Observe
recommended spacing from circulating air blower to heating unit. Locating the circulating air blower too close to the
unit creates uneven airflow over the heat exchanger resulting in poor performance and possible damage to heat
exchanger or components from localized overheating.
Never exceed the listed maximum rise temperatures for heaters. The rise limits are established based on
maintaining temperatures below the material maximum heat exchanger scaling temperatures during operation.
Airflow rates less than the listed minimums, or over-firing heater can result in excessive temperatures which can
also shorten heat exchanger life. A High Limit switch is provided that will shut-off the gas burner if the circulating air
temperature exceeds the maximum allowable. This limit switch is preset. DO NOT ADJUST limit setting.

6
Combustion Air Supply
The duct furnace needs an ample supply of air for proper and safe combustion of the fuel gas. Do not block or
obstruct air openings to the area where the heating unit is installed. Locate unit to insure an adequate supply
of fresh air to replace air used in the combustion and ventilation process.
For outdoor applications and for indoor applications where the combustion air is drawn from the surrounding space,
openings for combustion air must be provided in a panel or door with direct access to the vestibule area where
the burners and draft inducer are located. This air opening(s) must be sized to provide a suitable supply of air for
combustion to the burner compartment and have a minimum free area of 1 sq. in. (625mm2) per 4,000 Btuh
(2,345 W) of rated input for total input. The minimum dimension of any air opening should not be less than 3 inches.
The air handling unit must be installed so that access to air inlet openings is unobstructed. For louvered doors be
sure to provide a suitable windbreak to prevent wind driven rain and snow from collecting in the vestibule area and
on electrical components.
For indoor installations, locate heating unit to insure an adequate supply of fresh air to replace air used in the
combustion and ventilation process. Air must also enter the appliance location to replace the air exhausted through
the vent system. Refer to installation codes for specific requirements and guidelines.
Condensate Drain Lines
Condensate is produced in furnace sections during heating operation. The furnace has two collector box drain
fittings and one vent connector drain connection. Both indoor and outdoor furnaces must have condensate drains
piped to a sanitary sewer for disposal, using ¾” PVC pipe and fittings. Condensate drain piping is provided by others
except as noted.
Installation requires individual condensate drain systems for each duct furnace section.
The condensate drain system must include a trap for each furnace for proper system performance. Condensate
trap kits are provided with each duct furnace. All joints must be watertight to prevent leakage. Heat exchanger
assembly includes a threaded elbow oriented parallel to cabinet base. A male threaded PVC adapter is included
with the furnace to connect to the threaded elbows from the flue collector boxes. PVC materials used for condensate
drain piping and fittings must conform to ASTM D1785 / CSA B137.3.
Failure to connect condensate drains can result in
accumulation of condensate during heater operation and result
in damage to the heat exchanger and hazardous operation.
WARNING
!
Failure to connect and properly install condensate drains can result
in water flow into building, structural damage, injury or death.
WARNING !
For outdoor installations, the condensate drain line must be routed
through a heated space. DO NOT DRAIN ON ROOF. Failure to
properly connect condensate drain can result in significant
amounts of ice build-up, causing building damage, injury or death.
WARN
ING !

7
For outdoor installations run condensate drain from duct furnace into building (See Figure 2)
Figure 2 – Condensate Drain Piping
To Sanitary
Sewer
HepVo
Trap
¾” x 1½” M
Fitting
¾” x 1½” F
Fitting
Vent
Connector
Drain
Fitting Drain
Fitting
Outlet Flue
Collector Box
Insulated Cabinet Base
Roof Curb
Roof Deck
Primary
Collector Box
Float Switch
Float Switch Drain
Fitting
High Temp
Tubing
Before the Air Handling Unit (AHU) or Duct Furnace is placed on roof or curb, provide an opening for the
condensate drain through the roof structure to line up with drain connection opening in base of AHU / Duct Furnace
cabinet. Place unit on roof / curb and open front access panel.
Extend drain pipe(s) from inside the building up through the hole in the roof and cabinet, and into the ¾” fitting
provided on the condensate drain connection(s). Connect waterless condensate trap(s) provided to drain pipe inside
the building. Bushings are provided to connect trap to ¾” PVC pipe. Traps should be installed in the preferred
vertical position as shown in Fig.2. If trap must be installed horizontally for any reason, see instructions provided
with trap. Never connect condensate drain directly into a sewer line. If connection to a sewer is permitted by
code, drain line must terminate in an open sewer tap (separated from sewer pipe with an air gap).
To ensure piping is leak free, pipe sections must be solvent welded (glued) consistent with industry standards and
applicable codes. Installation of a union ahead of the trap is recommended to permit maintenance of drains and
accommodate service of the heater.
Where condensate drains are located outside a heated space or in a space where temperatures may fall below
freezing, the drain line must be protected from freezing. Use a shielded, waterproof, self-regulating heat tape
rated at 115 VAC, 40 oF (4.4 oC) suitable for condensate piping. Follow the heat tape manufacturer’s installation
recommendations. In certain applications insulating the condensate piping may be sufficient protection.
Disposal of condensate is subject to local codes and ordinances. In some locals the condensate drain system may
be connected to a sanitary drain within the building. Some municipalities require that the acidic condensate
produced be neutralized before being discharged into the sanitary sewer. A condensate neutralizer kit is available.
Refer to installation instructions provided with the kit. Locate neutralizer where it is readily accessible for inspection
and maintenance.
Where a floor drain is not accessible or available, a condensate pump may be used to pump condensate to sanitary
sewer above the unit. A condensate pump kit is available for these applications.
The drains must be extended
through the heater base and
into the heated space below
to prevent freezing of
condensate in the drain
piping. Trap must be located
in a heated space or
protected to avoid freezing.

8
IV. Venting
Installation of venting system must conform to local building codes and / or the National Fuel Gas Code
(ANSI Z223.1) or in Canada the Canadian Installation Code (CAN/CGA-B149).
Outdoor Installation
Flue gases (products of combustion) must be vented outside of the appliance. The vent discharge must be at least
the same diameter as the vent connector provided on the heating unit. For horizontal discharge, and animal screen
and rain cover are recommended. Care should be taken in final vent discharge location to prevent recirculation of
flue gases into combustion air supply.
Figure 3 –Outdoor Venting
Horizontal Vent
Vertical Vent
A vertical exhaust stack may be required to provide necessary clearances in some installations.

9
Indoor Installations
All duct furnaces must be connected to a venting system to convey flue gases outside of the heated space.
Duct furnaces for indoor installation are listed as Category II or IV vented appliances.
Vent pipe used must be certified to UL1738 / ULC S636 for a Category II, III and IV appliances. Joints must be
gas tight and watertight.
Vent pipe used must be of at least the same diameter as the furnace vent connector / collar provided (See
Table 1). All field installed vent pipe and fittings must be from the same manufacturer. DO NOT intermix vent
system parts from different vent manufacturers. Follow instruction provided with approved venting materials used.
Provide a minimum of 12 inches of straight vent pipe after the discharge connection before elbows.
Vent system and terminations shall be in accordance with requirements of authority having jurisdiction.
Do not connect the vent to any portion of a mechanical draft system that is under positive pressure. Do not install
dampers or other restrictive devices in vent.
Vent piping must be exclusive to a single furnace.
Typical Vertical and Horizontal Vent Arrangements
Fig. 4 - Vertical Vent (Category II)
WARNING !
Duct furnaces for indoor installation are equipped with a blocked vent
switch to shut-off gas supply to the main burner in the event that a
blockage occurs in the venting system. Do not disable or bypass this
switch. Disabling switch may result in hazardous operation.

10
Figure 5 – Horizontal Vent (Category IV)
Table 1 – Vent Connector Size
Model Size Input (Btuh)
Flue
Exhaust Dia.
(inch)
Max. Vent
Length
(ft.)
E
F
02
50
275,000
5
60
EF0400
450,000
6
60
EF055
0
600,000
8
60
EF0750
835,000
10
60
EF0900
1,000,000
10
60
EF1000
1,120,00
10
60
EF1250
1,400,000
12
60
EF1500
1,650,000
12
60
EF175
0
1,950,000
12
60
EF2
00
0
2,250,000
12
60
The maximum vent length is the equivalent length of pipe including any elbows and fittings. The equivalent length for
elbows based on pipe diameter are as follows: up to 6” diameter 5 ft., for 8” diameter 7.5 ft. and for 10 to 12”
diameter 10 ft.
Separated Combustion - Installations with Outdoor Combustion Air Supply
For installations requiring outside air for combustion, this duct furnace requires a two (2) pipe separated combustion
vent system with separate air intake and vent pipes terminating in the same pressure zone.
Use only Category II, III, IVI vent materials listed to UL1738 / ULC S636 for vent pipe and fittings. All field
installed vent pipe and fittings must be from the same manufacturer. DO NOT intermix vent system parts from
different vent manufacturers. Follow instruction provided with approved venting materials used.
Combustion air is supplied from outdoors into the furnace burner compartment through a properly sized pipe
attached to the air intake collar. Single wall galvanized pipe may be used for air supply pipes. Joints must be sealed
with silicone sealant or metallic tape.
Proper venting of the heating units is the responsibility of the installer. Vent and air piping materials are supplied by
others. Collars for connection of air pipe and listed vent piping are provided.

11
Figure 6 – Vent and Air Pipe Connections
Vent pipe and air inlet pipe are sized based on input rating of the furnace. See Table 2 for connector sizing and
materials based on model number and size. Minimum vent length is 5 ft.
Table 2 – Vent Connector and Combustion Air Pipe Sizing – Separated Combustion
The venting and combustion air supply must be exclusive to a single furnace. Separated
combustion systems may not be common vented
Vent and combustion air pipes must terminate in the same pressure zone. The maximum vent length is the
equivalent length of pipe including any elbows and fittings. Combustion air pipe should be approximately the same
length as the vent pipe and should not exceed 30 ft. in length. The vent and combustion air piping must be properly
supported. Horizontal vent sections must be installed with an upward pitch of not less than ¼ in/ft. (21 mm/m) and
securely supported every 3ft.
Both the furnace and vent system must be connected to a condensate removal system. The vent drip leg must use
reducers from the outlet to the drain connection to meet requirements for Canadian installations (OLC S636). This
method is also acceptable in the US.
Do not use dampers in vent or combustion air pipes. Vent and air pipe runs through unheated spaces must
be insulated or use double wall pipe.
Model
Size Input (Btuh)
Flue
Exhaust -
Diameter
(inches)
Air Intake -
Diameter
(inches)
Max.
Vent
Length
(ft.)
EF0250 275,000 5 5 30
EF0400 450,000 6 6 30
EF0550 600,000 8 8 30
EF0750 835,000 10 10 30
EF0900 1,000,000 10 10 30
EF1000 1,120,00 10 10 30
EF1250 1,400,000 12 12 30
EF1500 1,650,000 12 12 30
EF1750 1,950,000 12 12 30
EF2000 2,250,000 12 12 30

12
Indoor Vertical Venting
Vertical vent systems terminate vertically up. Install a Tee fitting with condensate drain connection as shown in
Figure 7. Vent and combustion air piping must be terminated as shown in Figure 8.
Figure 7 – Vertical Vent Pipe Connections
Figure 8 – Vertical Terminations
Vent Pipe
Combustion Air
Inlet Pipe
Roof flashing at
all penetrations
24" (0.6m) Minimum
From adjacent wall
or building
12" (0.3m)
Minimum
45o Elbow 90o Elbow
Vent Pipe
Install
Screen
Combustion Air
Inlet Pipe
Install
Screen
90o Elbow
18" (0.45m) Min.
Above roof or snow line
18" (0.45m) Min.
(Above combustion
air intake)
Indoor Horizontal Venting
Horizontal vent systems terminate horizontally. Install a Tee fitting with drip leg and cleanout trap as shown in Figure 9. Vent and
combustion air piping must be terminated as shown in Figure 10. All pipe openings external to building must have a protective
screen installed.
Figure 9 – Horizontal Vent Pipe Connections

13
Figure 10 – Horizontal Terminations
Vent Pipe
90o (or)
45o Elbow
Combustion Air
Inlet Pipe
18" (.045m) Min.
Above Grade or
Snow Line
6 ft. (1.8m)
To Adjacent Wall
Or Building
12" (0.3m) Minimum
Vent Pipe
Combustion Air
Inlet Pipe
12" (0.3m) Minimum
from adjacent wall
24" (0.6m)
Minimum
12" (0.3m)
Minimum
WARNING !
Duct furnaces are equipped with a float switch to shut-off gas
supply to the main burner in the event that a blockage occurs in
the condensate drain system resulting in back-up of condensate
into the flue collector box. Do not disable or bypass this level
switch. Disabling switch may result in hazardous operation.

14
V. Gas Supply, Piping and Connections
1. Installation of piping must conform with local building codes and ordinances, or in the absence of local codes
with ANSI Z223.1 the National Fuel Gas Code. In Canada, installation must be in accordance with CAN/CGA –
B149.1 for Natural gas and B149.2 for propane units.
2. Pipe joint compounds must be resistant to the action of liquefied petroleum (LP) gas.
3. The duct furnace requires a minimum inlet gas pressure of 7.0“ w.c. and a maximum inlet gas pressure of
13.5” w.c., with the furnace operating.
4. On multiple heater installations, a fitting suitable for connection to a pressure gauge capable of measuring gas
pressure should be connected to each heater serviced by a single regulator so that gas pressure at each heater
can be measured with all heaters in operation. Be sure that gas regulators servicing more than one heater have
the proper pipe and internal orifice size for the total input of all heaters serviced by the regulator.
(See Figure 11.)
Figure 11 – Multiple Heater Installation
5. A drip leg (sediment trap) and an external manual shut off valve must be provided upstream of the burner
supply piping on the heating unit. To facilitate servicing of unit, installation of a union is recommended. (See
Fig. 12)
Figure 12
6. Typical valve train and pressure measuring locations are shown in Figure 13.
7. Gas piping must be sized for the total Btu input of all units (heaters) serviced by a single supply. Refer to unit
manufacturer’s instructions for proper sizing.
Unit 1 Unit 2 Unit 3
Max. 13.5” w.c.
Minimum inlet pressure
required @ last heater.
Pressure
Regulator
Gas
Supply

15
Figure 13- Typical Gas Piping
WARNING !
1. All field gas piping must be
pressure / leak tested prior to
operation. NEVER use an open
flame to check for leaks. Use a
soap solution or other leak
detecting solution for testing.
2. Gas pressure to appliance
controls must never exceed 13.5”
w.c. (1/2 PSI)
WARNING !
1. When pressure testing at ½ PSI or
less, close the manual shut-off valve
on the appliance before testing.
2. When pressure testing gas supply
line at ½ PSI or higher, close manual
gas valve and disconnect heater from
supply line to be tested. Cap or plug
the supply line.
WARNING !
Failure to follow these instructions may result in a fire or explosion,
causing property da
mage
, personal injury, and / or l
oss of life.

16
VI. Electrical Requirements
All electrical equipment must be grounded and wired in accordance with the National Electric Code (ANSI/NFPA
70) in the United States, and the Canadian Electric Code (CSA C22.1), in Canada. The installer / equipment
manufacturer is responsible for final compliance with these requirements.
The furnace control system requires both line voltage and low voltage circuits with correct polarity, and clean
neutral and ground. Line voltage readings between L1 and Neutral as well as L1 and Ground should be within
+/- 3 volts.
A junction box for field connections is provided in the duct furnace vestibule.
The duct furnace is equipped with an automatic reset high limit switch (set at 170oF) and a circulating airflow
switch to insure that circulating air flow is present during main burner operation. See separate instruction sheet
for proper adjustment of airflow switch.
A manual reset auxiliary limit switch placed downstream of the duct furnace is recommended to avoid
overheating due to low airflow conditions.
A 2 to 10 VDC analog input from the temperature controller or BMS is required for system operation and
modulation of burner input rate.
Wiring Diagram – Honeywell 7800 Series Controller

17
Wiring Diagram – Siemens LME7 Controller
Electrical Ratings
Furnace
Model
Number
Burner
Model
Number
Supply
Voltage
(VAC)
Burner
Amps (Max)
EF0250
V1
115
4.8
EF0400
V1
115
4.8
EF0550
V2
115
6.8
EF0750
V2
115
6.8
EF0900
V2
115
6.8
EF1000
V4
115
12.0
EF1250
V4
115
12.0
E
F
1500
V4
115
12.0
EF1
75
0
V6
115
12.
5
EF2000
V6
115
12.5

18
Installer Safety Instructions
1. BEFORE OPERATING, Check both the supply lines and factory piping for leaks. Apply a soap and water
solution to all joints and watch for bubbles indicating a leak. NEVER test for gas leaks with an open flame.
2. Do not attempt to operate unit, if there is indication that any part or control has been under water. Any control or
component that has been under water must be replaced prior to trying to start the unit.
3. Verify gas supply and electrical supply provided match those listed on duct furnace rating plate
4. Before attempting start up, thoroughly familiarize yourself with the Honeywell Flame Safeguard (FSG) control
being used and its sequence of operation. Refer to documents provided with the burner. A Keyboard Display
Module is available to provide for annunciation of current system status and diagnosis during start-up and
adjustment.
VII. Initial Start-up
1. The gas burner has been factory tested and adjusted prior to shipping.
2. Start-up should be performed by a qualified burner technician to verify proper gas pressures and combustion
characteristics.
3. Refer to Rating Plate on Duct Furnace for input rating, manifold pressure and airflow information for this
furnace. Burner has been orificed for the maximum input rate marked at the manifold pressure indicated on the
rating plate.
4. Required test instruments include:
a. Combustion analyzer to measure CO2 (O2), CO
b. Temperature gage for measuring flue gas temperature (up to 550 oF) and outlet air temperature
c. Manometer or digital pressure gauge suitable for gaseous fuels
d. Volt-Ohm-Amp Meter
e. DC Volt generator analog input signal from temperature controller
Start-up Procedure
1. Install shut-off type pressure fittings in following tap locations shown in Figure 13; Inlet gas pressure, pilot
gas pressure, regulator outlet tap and manifold pressure tap.
2. Open external manual gas valve and verify that the inlet pressure is less than the maximum inlet pressure
marked on furnace rating plate.
3. Close manifold gas shut-off valve.
4. Open burner manual main shut-off valve
5. The following are required to initiate burner operation
a. 120 VAC power supply
b. On/Off switch on burner access door in “On” position
c. An analog input of at least 2.0 VDC from temperature control or DC Volt generator
d. A heat enable signal (binary)
6. Burner enters the pre-purge mode.
7. After a 30 to 90 second purge as determined by the burner controller, the burner will ignite the pilot.
8. After the pilot is established, the control will enter the run mode.
The power burner provided with this furnace requires a Qualified
Burner Technician for initial start-up. A flue gas analyzer must be
used when making any adjustments to insure proper combustion.
Improper set-up may result in hazardous operation.
WA
RNING !

19
9. Use a manometer to check the pilot pressure at the tap provided.
a) Pilot gas pressure should be 3.2” to 3.5” W.C
10. Open the Manifold gas shut-off valve. With an analog input of 2.0 VDC burner will run at low fire.
11. Using the observation window on the burner back plate look at the low fire condition. If light is visible
through all the holes in the burner plate, low fire is set within range. If flame is not visible through all holes,
then low fire setting is too low.
12. Locate the low fire bypass adjustment on the side of the Fuel Ratio Regulator.
13. Increase gas flow (turn adjusting screw counter-clockwise) until flame is visible through all holes.
14. Using a combustion analyzer, sample the flue gases at the vent discharge of the furnace. Verify that
readings range as follows:
Natural Gas Propane Gas
CO2…….. 1.5 to 2.8% 2.0 to 3.2%
O2…….. 16.0 to 18.5% 16.0 to 18.0%
CO …….. <100 ppm <100 ppm
Flue Gas Temp …….. < 100oF < 100oF
15. Modulate the burner to high fire by applying a 10 VDC analog input signal.
16. Verify the main regulator gas pressure setting as follows and adjust regulator if necessary:
a. Natural Gas – Regulator outlet pressure 6.0” W.C.
b. Propane Gas – Regulator outlet pressure 9.0” W.C.
17. Verify that the manifold pressure is the same as marked on the Furnace rating plate.
Note: Burners are not always set-up to their maximum capacity. The manifold pressure marked on
furnace rating plate or in the “Firing Rate” portion of the burner rating label, provides the correct fuel
input rating for the appliance.
18. Using a combustion analyzer, sample the flue gases at the vent discharge of the furnace. Verify that
readings range as follows:
Natural Gas Propane Gas
CO2…….. 8.5 to 10.0% 9.0 to 11.0%
O2…….. 3.0 to 5.0% 4.0 to 6.0%
CO …….. <100 ppm <100 ppm
Flue Gas Temp …….. < 150oF < 150oF
19. A Start-Up Data sheet is included with these instructions. Please complete this sheet and return the top
half to address shown. Keep bottom portion with instructions for future service reference.
20. Refer to the Burner Manufacturer’s instructions provided with this information package if any adjustments
need to be made to obtain correct manifold pressure or combustion characteristics.
Commissioning / Final Preparation
1. Remove call for heat (Open heat enable contact)
2. Close main manual shut-off gas valve.
3. Turn off main power disconnect and burner control panel switch
4. Remove pressure tap fittings and gauges used for pressure measurements. Replace pipe plugs.
5. Open main manual shut-off valve and check for leaks where pipe plugs were replaced.
6. Close main manual shut-off gas valve.
7. Reinstall caps to the pilot regulator, main regulator, low-fire bypass and ratio regulator that may have been
removed during start-up.
Never adjust burner for an input rate exceeding the maximum input marked on the
FURNACE rating plate. Damage to the furnace and hazardous operation can result.
W
ARNING !

20
VIII. Normal Operation
1. Open all manual gas valves
2. Turn on power at disconnect switch
3. Turn on power switch on burner control panel door
4. Set heat enable and temperature controller to desired operating condition and temperature
5. Burner will start and operate based on 2 to 10 VDC analog input provided.
IX. Duct Furnace and Burner Inspection & Maintenance
Turn off all electrical power and gas supply to the unit before inspection and servicing.
Periodic Inspection
Periodic maintenance inspections should be conducted to ensure that combustion air openings are clear and
clean of any dirt or debris that might restrict combustion air. Inspect vent stack for any deterioration. Inspect
condensate drains to insure there are no blockages during both air conditioning operation (summer season) as
well as during heating season.
Annual Maintenance and Inspection
The duct furnace should be inspected annually by a qualified service agency. The condition of the burners,
heat exchanger, vent system, operating controls, wiring and condensate removal system should be determined.
Check for obvious signs of deterioration, accumulation of dirt and debris and any heat or water related damage.
Any damaged or deteriorated parts should be replaced before the unit is put back into service. A combustion
analysis should be completed to be sure that system is performing as originally set-up.
1. Inspect and clean burner head, igniter, flame sensor and combustion air fan, removing any loose debris.
2. Inspect heat exchanger for any blockage or loose materials, deterioration, corrosion or cracks. If any are
present, replace heat exchanger before putting unit back into service. Inspect secondary tubes and clean as
necessary.
3. Check vent pipe and vent terminal for deterioration or debris. Clean or replace as necessary. Check joints
for tightness and ensure all connections are sealed.
4. Inspect condensate drain lines to be sure they are free of debris and free flowing. Clean condensate drain
trap(s).
5. If condensate neutralizer is installed, recharge per instructions.
6. Check condensate level switch for cleanliness and proper function.
7. Check the attachment point of the duct furnace to the cabinet or ducts to verify that they are airtight.
8. Inspect wiring for any loose connections, deterioration, abrasion or brittleness. Replace any wiring or
terminal connections that show signs of damage. Label all wires prior to disconnection when servicing unit.
Wiring errors can cause improper or dangerous operation. Verify proper operation after servicing.
9. Check the automatic gas valve(s) to ensure that the gas valve seat is not leaking.
10. Complete all safety and maintenance checks recommended by burner and flame safeguard manufacturers.
11. Verify proper system operation. See “Normal Operation” on Pg. 20
Heatco Inc.
50 Heatco Court
Cartersville, Ga. 30120
If any of the original wiring needs to be replaced it
must be replaced with wiring materials suitable for
105
o
C.
CAUTION !