Sterling Separated Combustion Tubular Gas Fired... Datasheet

(S) DSSCT-IOM-2
J30-06932
INSTALLER'S RESPONSIBILITY
Installer Please Note: This equipment has been test fired and inspected. It has been
shipped free from defects from our factory. However, shipment and installation
problems such as loose wires, leaks, or loose fasteners may occur. It is the installer's
responsibility to inspect and correct any problem that may be found.
RECEIVING INSTRUCTIONS
The Separated Combustion Tubular Unit Heaters are
shipped in two separate cartons: one containing the
unit and the other containing a Concentric Vent Kit. Both
pieces are required for each installation. Inspect shipment
immediately when received to determine if any damage has
occurred to the unit during shipment. After the unit has
been uncrated, check for any visible damage to the unit. If
any damage is found, the consignee should sign the bill of
lading indicating such damage and immediately file claim
for damage with the transportation company.
www.sterlinghvac.com
HVAC PRODUCTS
260 NORTH ELM ST., WESTFIELD, MA 01085
TEL: [phone] FAX: [phone]
MODELS: SF-30, 45, 60, 75
Model No. Serial No.
ATTENTION: READ THIS MANUAL AND ALL LABELS ATTACHED TO THE UNIT CAREFULLY BEFORE
ATTEMPTING TO INSTALL, OPERATE OR SERVICE THESE UNITS! CHECK UNIT DATA PLATE FOR TYPE OF GAS AND
ELECTRICAL SPECIFICATIONS AND MAKE CERTAIN THAT THESE AGREE WITH THOSE AT THE POINT OF INSTALLATION.
RECORD THE UNIT MODEL AND SERIAL No.(s) IN THE SPACE PROVIDED. RETAIN FOR FUTURE REFERENCE.
INSTALLATION INSTRUCTIONS AND PARTS LIST
SEPARATED COMBUSTION DIRECT SPARK TUBULAR UNIT HEATERS
(COMMERCIAL, INDUSTRIAL & RESIDENTIAL INSTALLATIONS)
08/06
Please utilize this toll free number to contact your local
representative 800-490-2290.
FOR YOUR SAFETY
WHAT TO DO IF YOU SMELL GAS
Do not try to light any appliance.
Do not touch any electrical switch; do
not use any phone in your building.
Immediately call your gas supplier
from a neighbor’s phone. Follow the
gas supplier’s instructions.
If you cannot reach your gas supplier,
call your fire department.
APPROVED FOR USE IN CALIFORNIA
Install, operate, and maintain unit in accordance with the manufacturer's
instructions to avoid exposure to fuel substances, or substances from incomplete combustion,
which can cause death or serious illness. The state of California has determined that these
substances may cause cancer, birth defects, or other reproductive harm.
Improper installation, adjustment, alteration, service, or maintenance can
cause property damage, injury, or death. Read the installation, operating, and
maintenance instruction thoroughly before installing or servicing this equipment.
FOR YOUR SAFETY
Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or
any other appliance.

2
TABLE OF CONTENTS
The following terms are used throughout this manual, in addition to the ETL requirements to bring attention to the
presence of potential hazards, or to important information concerning the product:
Indicates an imminently hazardous
situation which, if not avoided, will result in
death, serious injury, or substantial property
damage.
Indicates an imminently hazard-
ous situation which, if not avoided, could result
in death, serious injury, or substantial property
damage.
Indicates an imminently hazardous
situation which, if not avoided, may result in minor
injury or property damage.
NOTICE: Used to notify of special instructions on
installation, operation, or maintenance which are
important to equipment but not related to personal
injury.
SPECIFICATIONS
Basic Description .................................................... 2
Performance & Specification Data ..........................4
GENERAL SAFETY INFORMATION
Installation Codes ................................................ 2, 3
Special Precautions ............................................ 2, 3
INSTALLATION
Locating Units ..................................................... 5, 6
Combustion Air .................................................... 5, 6
Proper Clearances ..............................................5, 6
Suspension of Units ............................................5, 6
Gas Supply Piping ............................................... 7, 8
ELECTRICAL CONNECTIONS ............................. 9, 10
VENTING ........................................... 11, 12, 13, 14, 15
OPERATION
Explanation of Controls and Operation ................. 16
Main Burner Orifice Schedule ............................... 17
Adjustments .......................................................... 17
High Altitude Operation ...................................17, 18
MAINTENANCE
Servicing & Cleaning ............................................. 18
TROUBLESHOOTING GUIDE.................19, 20, 21, 22
IDENTIFICATION OF PARTS.............................. 23, 24
WARRANTY ............................................................... 25
INSPECTION SHEET ................................................ 26
See Identification of Parts throughout this manual.
DESCRIPTION
The Separated Combustion Tubular Gas Fired Unit
Heater is a factory assembled, separated combustion
system, low static pressure type propeller fan unit
heater designed to be suspended within the space to
be heated. THESE HEATERS ARE NOT TO BE
CONNECTED TO DUCTWORK. These unit heaters
are design certified under ANSI Z83.8 for industrial/
NOTICE: It is the equipment owners responsibility to provide any scaffolding or other apparatus required to
perform emergency service or annual/periodic maintenance to this equipment.
commercial use and CSA .10.96 U.S. (2nd ed.) for
residential use. The designs are certified by ETL as
providing a minimum of 80% thermal efficiency, and
approved for use in California. Do not alter these units
in any way. If you have any questions after reading
this manual, contact the manufacturer.
Figure 1 - Separated Combustion Tubular 30 thru 75 Unit Heaters

3
GENERAL SAFETY INFORMATION
Failure to comply with the general
safety information may result in extensive
property damage, severe personal injury, or
death.
Installation must be made in accordance with local
codes, or in absence of local codes, with the latest
edition of ANSI Standard Z223.1 (N.F.P.A. No. 54)
National Fuel Gas Code. All of the ANSI and NFPA
Standards referred to in these installation instructions
are those that were applicable at the time the design of
this appliance was certified. The ANSI Standards
are available from CSA Information Services,1-800-463-
6727. The NFPA Standards are available from the
National Fire Protection Association, Batterymarch Park,
Quincy, MA 02269.
If installed in Canada, the installation must conform with
local building codes, or in the absence of local building
codes, with CGA-B149.1 "Installation Codes for Natural
Gas Burning Appliances and Equipment" or CGA-B149.2
"Installation Codes for Propane Gas Burning Appliances
and Equipment." These unit heaters have been designed
and certified to comply with CGA 2.6.
Do not alter the unit heater in any
way or damage to the unit and/or severe personal
injury or death may occur!
Disconnect all power and gas
supplies before installing or servicing the heater.
If the power disconnect is out of sight, lock it in
the open position and tag it to prevent unexpected
application of power. Failure to do so could result
in fatal electric shock, or severe personal injury.
Ensure that all power sources conform
to the requirements of the unit heater, or damage to
the unit will result!
Follow installation instructions CAREFULLY to avoid
creating unsafe conditions. All wiring should be done
and checked by a qualified electrician, using copper wire
only. All gas connections should be made and leak-
tested by a suitably qualified individual, per instructions
in this manual. Also follow procedures listed on "Gas
Equipment Start-Up Sheet" located in this manual.
Use only the fuel for which the heater is designed (see
rating plate). Using LP gas in a heater that requires
natural gas, or vice versa, will create risk of gas leaks,
carbon monoxide poisoning, and explosion.
This product must be installed by
a licensed plumber or gas fitter when installed
within the Commonwealth of Massachusetts.
Do not attempt to convert the
heater for use with a fuel other than the one
intended. Such conversion is dangerous, as it
will create the risks previously listed.
Make certain that the power source conforms to the
electrical requirements of the heater.
Do not depend upon a thermostat
or other switch as sole means of disconnecting
power when installing or servicing heater. Always
disconnect power at main circuit breaker as
described above. Failure to do so could result in
fatal electric shock.
Special attention must be given to any grounding
information pertaining to this heater. To prevent the risk
of electrocution, the heater must be securely and
adequately grounded. This should be accomplished by
connecting a ground conductor between the service panel
and the heater. To ensure a proper ground, the grounding
means must be tested by a qualified electrician.
Do not insert fingers or foreign objects into heater or its
air moving device. Do not block or tamper with the heater
in any manner while in operation, or just after it has been
turned off, as some parts maybe hot enough to cause
injury.
This heater is intended for general heating applications
ONLY. It must NOT be used in potentially dangerous
locations such as flammable, explosive, chemical-laden,
or wet atmospheres.
Do not attach ductwork to this product or use it as a
makeup air heater. Such usage voids the warranty and
will create unsafe operation.
In cases in which property damage may result from
malfunction of the heater, a back-up system or
temperature sensitive alarm should be used.
The open end of piping systems being
purged shall not discharge into areas where there
are sources of ignition or into confined spaces
UNLESS precautions are taken as follows: (1) by
ventilation of the space, (2) control of the purging
rate, (3) elimination of all hazardous conditions. All
precautions must be taken to perform this operation
in a safe manner!
Unless otherwise specified, the following conversions
may be used for calculating SI unit measurements:
1 foot = 0.305 m
1 inch = 25.4 mm
1 gallon = 3.785 L
1 pound = 0.453 kg
1 psig = 6.894 kPa
1 cubic foot = 0.028m3
1000 BTU/cu. ft. = 37.5 MJ/m3
1000 BTU per hour = 0.293 kW
1 inch water column = 0.249 kPa
liter/second = CFM x 0.472
meters/second = FPM ÷ 196.8

4
Table 1 - Performance and Dimensional Data - Tubular 30 thru 75 Propeller Unit Heater
Figure 2 - Dimensional Drawing – Separated Combustion 30 thru 75 Propeller Unit Heater
Unit Size 30 45 60 75
PERFORMANCE DATA†
Input - BTU/Hr. 30,000 45,000 60,000 75,000
(kW) (8.8) (13.2) (17.6) (22.0)
Output - BTU/Hr. 24,300 36,450 48,600 60,750
(kW) (7.1) (10.7) (14.2) (17.8)
Thermal Efficiency (%) 81 81 81 81
Free Air Delivery - CFM 500 750 1,000 1,250
(cu. m/s) (0.236) (0.355) (0.473) (0.591)
Air Temperature Rise - Deg. F 45 45 45 45
(Deg. C) (25) (25) (25) (25)
Full Load Amps at 120V ** 3.0 3.0 3.7 3.7
MOTOR DATA: Motor HP 1/20 1/20 1/20 1/20
Motor (kW) (0.037) (0.037) (0.037) (0.037)
Motor Type SP SP SP SP
R.P.M. 1650 1650 1050 1050
Motor Amps @ 115V 1.9 1.9 2.6 2.6
DIMENSIONAL DATA - inches (mm)
“A” Jacket Height 12 12 17-3/4 17-3/4
(305) (305) (451) (451)
“B” Overall Height 13 13 18-3/4 18-3/4
(330) (330) (476) (476)
“C” Overall Depth 25-1/2 25-1/2 26-3/4 26-3/4
(648) (648) (679) (679)
“D” Center Line Height of Flue 7-1/4 7-1/4 10 10
(184) (184) (254) (254)
“E”
Center Line Height of Combustion Air Inlet 9 9 14-3/4 14-3/4
(229) (229) (375) (375)
“F” Discharge Opening Height 10-1/2 10-1/2 16-1/4 16-1/4
(267) (267) (413) (413)
“G” Fan Diameter-in 10 10 16 16
Unit Weight - lbs. 62 68 87 93
(kgs) (28) (31) (39) (42)
Shipping Weight - lbs. 72 78 102 108
(kgs) (33) (35) (46) (49)
DIMENSIONS .XXX STANDARD UNITS
DIMENSIONS IN PARENTHESIS (XXX) MILLIMETERS
† Ratings shown are for unit installations at elevations between 0 and 2,000 ft (0 to 610m). For unit installations in U.S.A. above 2,000 ft. (610m), the unit input must be derated 4% for each 1,000 ft. (305m) above sea
level; refer to local codes, or in absence of local codes, refer to the the latest edition of the National Fuel Gas Code, ANSI Standard Z223.1 (N.F.P.A. No. 54).
For installations in Canada, any reference to deration at altitudes in excess of 2,000 ft. (610m) are to be ignored. At altitudes of 2,000 ft. to 4,500 ft. (610 to 1372m), the unit must be derated to 90% of the normal
altitude rating, and be so marked in accordance with the ETL certification.
(Natural & Propane Gas)
27-3/8" (695mm) Maximum Hanger Spacing
24" (610mm) Hanger Spacing
16" (406mm) Hanger Spacing
21-1/2" Hanger Spacing
Gas Connection 1/2 Inch N.P.T.
Electrical Connection
2-1/2"(64mm)
Inlet Connection
4 Inch (102 MM)
Rear View
Fan Dia. "G"
B
Vent Connection
4 Inch (102 MM)
4-1/2" (114mm)
4-1/4" (108mm)
1-3/4" (44mm)
(203mm)
8"
DE
Combustion Air
Top View
(546mm)
Adjustable Louvers
Front View
(400mm)
Opening
Discharge
15-3/4"
(727mm)
28-5/8"
Side View
(514mm)
20-1/4"
CAccess Panel
Spacing
21-1/2"
Hanger
(546mm)
A
(19mm)
3/4"
Opening
Discharge
F
3/4"
(19mm)
D3323

5
INSTALLATION
Do not install unit heaters in
corrosive or flammable atmospheres! Premature
failure of, or severe damage to the unit will
result!
Avoid locations where extreme
drafts can affect burner operation. Unit heaters
must not be installed in locations where air for
combustion would contain chlorinated,
halogenated or acidic vapors. If located in such
an environment, premature failure of the unit
will occur!
Since the unit is equipped with an automatic gas ignition
system, the unit heater must be installed such that the
gas ignition control system is not directly exposed to
water spray, rain or dripping water.
NOTICE: Location of unit heaters is related directly
to the selection of sizes. Basic rules are as follows:
MOUNTING HEIGHT: If the unit heater is installed in a
garage, it must be installed with a minimum clearance
above the floor of 18 inches (457mm).
AIR DISTRIBUTION: Direct air towards areas of
maximum heat loss. When multiple heaters are involved,
circulation of air around the perimeter is recommended
where heated air flows along exposed walls. Satisfactory
results can also be obtained where multiple heaters are
located toward the center of the area with heated air
directed toward the outside walls. Be careful to avoid
all obstacles and obstructions which could impede the
warm air distribution patterns.
Unit heaters should not be installed to maintain low
temperatures and/or freeze protection of buildings.
A minimum of 50°F (10°C) thermostat setting must
be maintained. If unit heaters are operated to maintain
lower than 50°F (10°C), hot flue gases are cooled inside
the heat exchanger to a point where water vapor (a flue
gas by-product) condenses onto the heat exchanger
walls. The result is a mildly corrosive acid that
prematurely corrodes the aluminized heat exchanger
and can actually drip water down from the unit heater
onto floor surface. Additional unit heaters should be
installed if a minimum 50°F (10°C) thermostat setting
cannot be maintained.
NOTICE: Unit Heater sizing should be based on heat
loss calculations where the unit heater output equals
or exceeds heat loss.
AIRCRAFT HANGARS: Unit Heaters must be installed
in aircraft hangars and public garages as follows: In
aircraft hangars, unit heaters must be at least 10 feet
(3.05m) above the upper surface of wings or engine
enclosures of the highest aircraft to be stored in the
hangar and 8 feet (2.44m) above the floor in shops, offices
and other sections of the hangar where aircraft are not
stored or housed. Refer to current ANSI/NFPA No. 409,
Aircraft Hangars. In Canada, installation is suitable in
aircraft hangars when acceptable to the enforcing
authorities.
PUBLIC GARAGES: In repair garages, unit heaters
must be at least 8 feet (2.4m) above the floor. Refer to
the latest edition of NFPA 88B, Repair Garages.
In parking structures, unit heaters must be installed so
that the burner flames are located a minimum of 18 in.
(457mm) above the floor or protected by a partion not
less than 18 in. (457mm) high. However, any unit heater
mounted in a parking structure less than 8 feet. (2.4m)
above the floor must be equipped with an OSHA ap-
proved fan guard. Refer to the latest edition of NFPA
88A, Parking Structures.
In Canada, installation must be in accordance with the
latest edition of CGA B149 “Installation Codes for Gas
Burning Appliances and Equipment.”
CLEARANCES: Each Gas Unit Heater shall be located
with respect to building construction and other equipment
so as to permit access to the Unit Heater. Clearance
between vertical walls and the vertical sides of the Unit
Heater shall be no less than 1 inch (25.4mm). However,
to ensure access to the control box and fan, a minimum
of 18" (457mm) is required for the fan, and control box
side. A minimum clearance of 1 inch (25.4mm) must be
maintained between the top of the Unit Heater and the
ceiling. The bottom of the Unit Heater must be no less
than 1 inch (25.4mm) from any combustible. The
distance between the flue collector and any combustible
must be no less than 1 inch (25.4mm). Also see
VENTING section.
NOTICE: Increasing the clearance distances may
be necessary if there is a possibility of distortion or
discoloration of adjacent materials.
MOUNTING: The Unit Heater may be mounted with the
vent outlet, gas and electrical connections to the right
or left of the air moving fan. The Unit Heater is shipped
with the connections to the right of the fan when looking
in the direction of the air flow. If connections to the right
are required, remove hanger brackets from face of unit
and attach as pictured in Figure 3A. If connections to
the left are required, invert the heater (180°), mount the
hanging brackets as above, and remove, invert, and
replace the control access panel and the air discharge
louvers.

6
INSTALLATION (continued)
The Unit Heater may be mounted by
fastening the hanging brackets directly
to ceiling joists or by suspending from
four rods. See Figures 3A, 3B and 3C.
Make certain that
the lifting methods used to lift the
heater and the method of suspen-
sion used in the field installation
of the heater are capable of
uniformly supporting the weight
of the heater at all times. Failure
to heed this warning may result in
property damage or personal
injury!
Make sure that the
structure to which the unit heater
is to be mounted is capable of
safely supporting its weight.
Under no circumstances must the
gas lines, the venting system or
the electrical conduit be used to
support the heater; or should any
other objects (i.e. ladder, person)
lean against the heater gas lines,
venting system or the electrical
conduit for support. Failure to
heed these warnings may result
in property damage, personal
injury, or death.
Unit Heaters must be
hung level from side to side and from
front to back, see Figures 3A, 3B and
3C. Failure to do so will result in poor
performance and/or premature failure
of the unit.
Ensure that all
hardware used in the suspension
of each unit heater is more
than adequate for the job. Failure
to do so may result in extensive
property damage, severe personal
injury, or death!
Refer to Figures 3A, 3B and 3C for
suspension of units.
Figure 3C - Heater Mounting (Wood Construction)
Figure 3A -
Hanger Bracket
Installation Instructions
Figure 3B - Heater Mounting (Steel Construction)
both sides of Bracket
Rear View
(695)mm
Threaded Rod
Hanger Spacing
Nuts and Washers
27-3/8" Max.
STEEL CONSTRUCTION
Side View
(546mm)
Hanger Spacing
D 03334
21-1/2"
WOOD CONSTRUCTION
Rear View
and Washer
Lag Bolt
Joist
Joist Centers
(406 to 610mm)
16" to 24"
Side View
(546mm)
21-1/2"
D 03333

7
GAS PIPING
To avoid damage or possible personal injury, do not connect gas piping to this unit
until a supply line pressure/leak test has been completed. Connecting the unit before completing the
pressure/leak test may damage the unit gas valve and result in a fire hazard.
Do not rely on a shut-off valve to isolate the unit while conducting gas pressure/leak
tests. These valves may not be completely shut off, exposing the gas valve to excessive pressure and
damage.
NOTICE: If more than one unit heater is to be served
by the same piping arrangement, the total cu. ft./hr.
input and length of pipe must be considered.
NOTICE: If the gas unit heater is to be fired with LP
gas, consult your local LP gas dealer for pipe size
information.
NOTICE: HEATER INSTALLATION FOR USE WITH
PROPANE (BOTTLED) GAS MUST BE MADE BY A
QUALIFIED L.P. GAS DEALER OR INSTALLER. HE
WILL INSURE THAT PROPER JOINT COMPOUNDS
ARE USED FOR MAKING PIPE CONNECTIONS;
THAT AIR IS PURGED FROM LINES; THAT A
THOROUGH TEST IS MADE FOR LEAKS BEFORE
OPERATING THE HEATER; AND THAT IT IS
PROPERLY CONNECTED TO THE PROPANE GAS
SUPPLY SYSTEM.
Before any connection is made to the existing line
supplying other gas appliances, contact the local gas
company to make sure that the existing line is of
adequate size to handle the combined load.
1. Determine the required Cu. Ft./Hr. by dividing the input by 1000. For SI/Metric measurements: Convert BTU/Hr. to kilowatts. Multiply the
units inputs (kW) by 0.0965 to determine Cu. Meters./Hr. 2. FOR NATURAL GAS: Select pipe size directly from the table. 3. FOR PROPANE
GAS: Multiply the Cu. Ft./Hr. value by 0.633; then, use the table. 4. Refer to the metric conversion factors listed in the General Safety section
for SI Unit measurement conversions.
Maximum Capacity of Pipe in Cubic Feet of Gas per Hour (Cubic Meters per Hour) for Gas Pressures of 0.5 psig (3.5 kPa) or Less,
and a Pressure Drop of 0.5 Inch Water Column (124.4 Pa)
(Based on a 0.60 Specific Gravity Gas)
Nominal
Iron Internal Length of Pipe, Feet (meters)
Pipe Size Dia. 10 20 30 40 50 60 70 80 90 100 125 150 175 200
in. in. (3.0) (6.1) (9.1) (12.2) (15.2) (18.3) (21.3) (24.4) (27.4) (30.5) (38.1) (45.7) (53.3) (61.0)
1/2 0.622 175 120 97 82 73 66 61 57 53 50 44 40 37 35
(4.96) (3.40) (2.75) (2.32) (2.07) (1.87) (1.73) (1.61) (1.50) (1.42) (1.25) (1.13) (1.05) (0.99)
3/4 0.824 360 250 200 170 151 138 125 118 110 103 93 84 77 72
(10.2) (7.08) (5.66) (4.81) (4.28) (3.91) (3.54) (3.34) (3.11) (2.92) (2.63) (2.38) (2.18) (2.04)
1 1.049 680 465 375 320 285 260 240 220 205 195 175 160 145 135
(19.3) (13.2) (10.6) (9.06) (8.07) (7.36) (6.80) (6.23) (5.80) (5.52) (4.96) (4.53) (4.11) (3.82)
1 1/4 1.380 1400 950 770 660 580 530 490 460 430 400 360 325 300 280
(39.6) (26.9) (21.8) (18.7) (16.4) (15.0) (13.9) (13.0) (12.2) (11.3) (10.2) (9.20) (8.50) (7.93)
1 1/2 1.610 2100 1460 1180 990 900 810 750 690 650 620 550 500 460 430
(59.5) (41.3) (33.4) (28.0) (25.5) (22.9) (21.2) (19.5) (18.4) (17.6) (15.6) (14.2) (13.0) (12.2)
2 2.067 3950 2750 2200 1900 1680 1520 1400 1300 1220 1150 1020 950 850 800
(112) (77.9) (62.3) (53.8) (47.6) (43.0) (39.6) (36.8) (34.5) (32.6) (28.9) (26.9) (24.1) (22.7)
2 1/2 2.469 6300 4350 3520 3000 2650 2400 2250 2050 1950 1850 1650 1500 1370 1280
(178) (123) (99.7) (85.0) (75.0) (68.0) (63.7) (58.0) (55.2) (52.4) (46.7) (42.5) (38.8) (36.2)
3 3.068 11000 7700 6250 5300 4750 4300 3900 3700 3450 3250 2950 2650 2450 2280
(311) (218) (177) (150) (135) (122) (110) (105) (97.7) (92.0) (83.5) (75.0) (69.4) (64.6)
4 4.026 23000 15800 12800 10900 9700 8800 8100 7500 7200 6700 6000 5500 5000 4600
(651) (447) (362) (309) (275) (249) (229) (212) (204) (190) (170) (156) (142) (130)
Table 2 - Gas Pipe Size
PIPE SIZING
To provide adequate gas pressure to the gas unit heater,
size the gas piping as follows:
1. Find the cu. ft./hr. by using the following formula:
Input
Cu. ft./hr. =
BTU
2. Refer to Table 2. Match “Length of Pipe in Feet”
with appropriate “Gas Input - Cu. Ft./Hr.” figure.
This figure can then be matched to the pipe size at
the top of the column.
Example:
It is determined that a 67 foot (20.4m) run of gas
pipe is required to connect a 75 MBTU gas unit
heater to a 1,000 BTU/cu ft. (0.29kW) natural gas
supply.
75,000 BTU/Hr
= 75 Cu. ft./hr.
1,000 BTU/cu. ft.
Using Table 2, a 3/4 inch pipe is needed.
NOTE: See General Safety Information section for
English/Metric unit conversion factors.

8
PIPE INSTALLATION
Do not over tighten the inlet gas
piping into the valve. This may cause stresses that
will crack the valve!
NOTICE: Use pipe joint sealant resistant to the action
of liquefied petroleum gases regardless of gas
conducted.
Check all pipe joints for leakage
using a soap solution or other approved method.
Never use an open flame or severe personal
injury or death may occur!
Figure 4 - Pipe Installation, Standard Controls
Never use an open flame to
detect gas leaks. Explosive conditions may exist
which may result in personal injury or death!
The appliance and its individual shutoff valve must be
disconnected from the gas supply piping system during
any pressure testing of that system in excess of 1/2
psig (3.5 kPa).
The appliance must be isolated from the gas supply
piping system by closing its individual manual shutoff
valve during any pressure testing of the gas supply
piping system at test pressures equal to or less than
1/2 psig (3.5 kPa).
1. Install the gas piping in accordance with applicable
local codes.
2. Check gas supply pressure. Each unit heater must
be connected to a gas supply capable of supplying
its full rated capacity at a pressure not less than 5
in. W.C. (1.2 kPa), and not greater than 14 in. W.C.
(3.5 kPa) for natural gas. The manifold pressure for
natural gas must be 3.5 in. W.C. (0.9 kPa) under
normal conditions. For propane gas operation, the
manifold pressure must be 10 in. W.C. (2.5 kPa).
For propane (LP) gas, the minimum supply pressure
must be 11 in. W.C. (2.7 kPa). A field LP tank
regulator must be used to limit the supply pressure
to a maximum of 14 in. W.C. (3.5 kPa). All piping
should be sized in accordance with the latest edition
of ANSI Standard Z223.1 National Fuel Gas Code;
in Canada, according to CGA-B149. See Tables 1
& 2 for correct gas piping size. If gas pressure is
excessive on natural gas applications, install a
pressure regulating valve in the line upstream from
the main shutoff valve.
3. Adequately support the piping to prevent strain on
the gas manifold and controls.
4. To prevent the mixing of moisture with gas, run the
take-off piping from the top, or side, of the main.
5. Standard Unit Heaters are supplied with a
combination valve which includes:
a. Manual "A" valve
b. Manual "B" valve
c. Solenoid valve
d. Pressure regulator
Pipe directly into the combination valve (see Figure
4).
6. Gas valve has a pressure test post requiring a
3/32" hex head wrench to read gas supply and
manifold pressures. Open 1/4 turn counterclockwise
to read, turn clockwise to close and reseat. A 5/16"
ID hose fits the pressure post.
7. Provide a drip leg in the gas piping near the gas
unit heater. A ground joint union and a manual gas
shutoff valve should be installed ahead of the unit
heater controls to permit servicing. The manual
shutoff valve must be located external to the jacket.
(See Figure 4)
8. Make certain that all connections have been
adequately doped and tightened.

9
ELECTRICAL CONNECTIONS
THERMOSTAT WIRING AND LOCATION:
NOTICE: The thermostat must be mounted on a
vertical, vibration-free surface, free from air currents,
and in accordance with the furnished instructions.
Mount the thermostat approximately 5 feet (1.5m) above
the floor, in an area where it will be exposed to a free
circulation of average temperature air. Always refer to
the thermostat instructions, as well as our unit wiring
diagram, and wire accordingly. Avoid mounting the
thermostat in the following locations:
1. Cold Areas- Outside walls or areas where drafts
may affect the operation of the control.
2. Hot Areas- Areas where the sun's rays, radiation, or
warm air currents may affect the operation of the
control.
3. Dead Areas- Areas where the air cannot circulate
freely, such as behind doors or in corners.
THERMOSTAT HEAT ANTICIPATOR ADJUSTMENTS:
The initial heat anticipator setpoint should equal the
thermostat's current amperage draw when the unit is
firing. This setpoint should be measured for the best
results. Use the recommended ranges for a guide. If
further information is needed, consult your thermostat
manufacturer's instructions.
Recommended heat anticipator setting:
Unit Size: 30 thru 200 250 thru 400
For Tubular Units: 0.35 Amps 0.65 Amps
NOTICE: The start-up fan delay should not exceed
30 seconds from a cold start.
IMPORTANT: For all wiring connections, refer to the
wiring diagram shipped with your unit (either affixed
to the side jacket or enclosed in the installation
instructions envelope). Should any original wire
supplied with the heater have to be replaced, it must
be replaced with wiring material having a temperature
rating of at least 105° C.
Figure 5B - T834H-1009 or T834H-1017
Thermostat Wiring
Figure 5A - Low-voltage Thermostat Wiring
Single Stage
HAZARDOUS VOLTAGE!
DISCONNECT ALL ELECTRIC
POWER INCLUDING REMOTE
DISCONNECTS BEFORE
SERVICING. Failure to
disconnect power before
servicing can cause severe
personal injury or death.
Standard units are shipped for use on 115 volt, 60 hertz,
single phase electric power. The motor name-plate and
electrical rating of the transformer should be checked
before energizing the unit heater electrical system. All
external wiring must conform to the latest edition of
ANSI/NFPA No. 70, National Electrical Code, and
applicable local codes; in Canada, to the Canadian
Electrical Code, Part 1, CSA Standard C22.1.
Do not use any tools (i.e. screwdriver,
pliers, etc.) across terminals to check for power.
Use a voltmeter.
It is recommended that the electrical power supply to
each unit heater be provided by a separate, fused, and
permanently live electrical circuit. A disconnect switch of
suitable electrical rating should be located as close to
the gas valve and controls as possible. Each unit heater
must be electrically grounded in accordance with the
latest edition of the National Electrical Code, ANSI/NFPA
No. 70, or CSA Standard C22.1. Refer to Figures 5A, 5B,
and 5C.
RGW1W2
WR
G
Honeywell
T834H-1009
or
T834H-1017
Thermostat
D6922B

10
ELECTRICAL CONNECTIONS (continued)
Figure 5C - Separated Combustion Tubular Propeller Units
with Natural and Propane (LP) Gas
NOTICE: See Figures 5A, 5B and 5C for
connecting the thermostat to the unit
heater. If using a standard low voltage
thermostat with a sub-base switch for fan
control, connect the G terminal of the
thermostat to the G terminal of the unit
heater.

11
INSTALLATION - VENTING
COMBUSTION AIR VENTING AND PIPING
Never operate unit heaters without
combustion air and flue gas piping in place or
severe personal injury or death may occur!
CARBON MONOXIDE!
Your venting system must not be blocked by any
snow, snow drifts, or any foreign matter. Inspect
your venting system to ensure adequate ventilation
exists at all times! Failure to heed these warnings
could result in Carbon Monoxide Poisoning
(symptoms include grogginess, lethargy,
inappropriate tiredness, or flu-like symptoms).
1. The combustion air system installation must be in
accordance with the current edition of the National
Fuel Gas Code-NFPA 54 or ANSI Z223.1 National
Fuel Gas Code. In Canada, installation must be in
accordance with CAN/CGA-B149.1 “Installation Code
for Natural Gas Burning Appliances and Equipment”
and CAN/CGA-B149.2 “Installation Code for Propane
Burning Appliances and Equipment”.
2. The concentric vent box, inlet air screen, deflector
disk, and vent terminal provided with the unit heater
must be installed at the termination point of the
combustion air/vent system. See Figures 6, 7, 8,
and 9 and Table 3.
3. Each unit heater MUST have its own combustion
air system. It MUST NOT be connected to other air
intake systems.
4. Use single wall pipe constructed of 26 GA
galvanized steel or a material of equivalent durability
and corrosion resistance for the vent system. For
installations in Canada, use pipe constructed from
.025 inch thick aluminum or .018 inch thickness
stainless steel. For residential installations in the
United States, vent pipe approved for Category III
appliances must be used between the appliance and
the concentric vent box unless 33% of the vent run is
vertical, then single wall galvanized vent pipe or
double wall Type B vent pipe may be used between
the appliance and the concentric vent box. A single
length of double wall Type B vent pipe must be used
to go through the concentric vent box and outside
wall to the vent terminal.
Never use pipe other than 4 inch
diameter. Never use PVC, ABS or any other non-
metallic pipe for venting! To do so may result
in serious damage to the unit and or severe
personal injury or death!
5. Long runs of single wall combustion air piping
passing through an unheated space may require
insulating if condensation becomes noticeable.
6. The combustion air system must be installed to
prevent collection of condensate. Pitch horizontal
pipes downward 1/4 inch per foot toward the inlet
cap to facilitate drainage. Vertical combustion air
pipes should be piped as depicted in Figure 7.
7. The equivalent length of the combustion air system
must not be less than 5 feet (1.5m) and must not
exceed 40 feet (12m). Equivalent length equals the
total length of straight pipe plus 5 feet (1.5m) for each
90° elbow and 2.5 feet (0.76m) for each 45° elbow.
NOTICE: For optimum performance keep the
combustion air system as straight as possible.
8. Each slip joint must be secured with at least three
corrosion resistant screws. Two full turns of 3M #425
Aluminum Foil Tape or its equivalent must then be
used to seal each joint. General Electric RTV-108,
Dow-Corning RTV-732 or an equivalent silicone
sealant with a temperature rating of 500°F may be
used instead of the tape.
9. For horizontal combustion air systems longer than 5
feet (1.5m), the system must be supported from
overhead building structures at 4 foot (1.2m) intervals
in the U.S. and at 3 foot (0.91m) intervals in Canada.
EXHAUST VENTING
NOTICE: Every unit to be installed MUST use the
Factory supplied Concentric Vent Kit. A Concentric
Vent Kit is shipped with every unit. If you do not
have this kit, contact the manufacturer ASAP to
obtain one prior to installation.
Never operate unit heaters with-
out combustion air and flue gas piping in place or
severe personal injury or death may occur!
1. Vent system installation must be in accordance with
the current National Fuel Gas Code-NFPA 54 or ANSI
Z223.1 National Fuel Gas Code. In Canada installation
must be in accordance with CAN/CGA-B149.1
“Installation Code for Natural Gas Burning Appliances
and Equipment” and CAN/CGA-B149.2. “Installation
Code for Propane Burning Appliances and Equipment”.
2. The Concentric Vent Kit (which includes a
concentric vent box, air inlet screen, deflector
collar and vent terminal) provided with the heater
by the manufacturer MUST be installed at the
termination point of the combustion air/ vent
system. See Figures 6, 7, 8, and 9 and Table 3.
3. Each unit heater MUST have it’s own vent system.
It MUST NOT be connected to other vent systems
or to a chimney.
4. Use single wall pipe constructed of 26 GA galvanized
steel or a material of equivalent durability and corrosion
resistance for the vent system. For installations in
Canada, use pipe constructed from .025 inch thick
aluminum or .018 inch thick stainless steel. For
residential installations in the United States, vent pipe
approved for Category III appliances must be used
between the appliance and the concentric vent box
unless 33% of the vent run is vertical, then single wall
galvanized vent pipe or double wall Type B vent pipe
may be used between the appliance and the concentric
vent box. A single length of double wall Type B vent
pipe must be used to go through the concentric vent
box and outside wall to the vent terminal.

12
VENTING (continued)
Never use pipe other than 4 inch
diameter. Never use PVC, ABS or any other non-
metallic pipe for venting! To do so may result in
serious damage to the unit and or severe per-
sonal injury or death!
5. Any run of single wall vent pipe passing through an
unheated space must be insulated with an insulation
suitable to 550° F.
6. The vent system must be installed to prevent
collection of condensate. Pitch horizontal pipes
downward 1/4 inch per foot (21mm per meter)
toward the vent cap to facilitate drainage. Vertical
vent pipes should be piped as depicted in Figure 7.
7. The equivalent length of the vent system must not
be less than 5 feet (1.5m) and must not exceed 40
feet (12m). The equivalent length equals the total
length of straight pipe plus 5 feet (1.5m) for each
90° elbow and 2.5 feet (0.76m) for each 45° elbow.
8. Each slip joint must be secured with at least three
corrosion resistant screws. Two full turns of 3M #425
Aluminum Foil tape or its equivalent must then be
used to seal each joint. High temperature silicone
sealant may be used instead of the tape. Silicone
sealant must be used to seal the joint between the
Type B vent pipe and the single wall pipe.
9. For horizontal vent systems longer than 5 feet
(1.5m), the system must be supported from
overhead building structures at 4 foot (1.2m)
intervals in the U.S. and at 3 foot (0.91m) intervals
in Canada.
10. The exhaust vent system must remain at a minimum
distance of 1 inch (25mm) from all combustible
materials. Any part of the vent system that passes
through a combustible material must be properly
insulated.
NOTICE: Increasing the clearance distances may be
necessary if there is a possibility of distortion or
discoloration of adjacent materials.
11. The top of a VERTICALLY VENTED exhaust system
must extend at least 3 feet (0.91m) above the roof
surface that it passes through. See Figure 7.
12. The point of termination for a HORIZONTALLY
VENTED exhaust system must be at least 12 inches
(0.3m) from the exterior of the wall that it passes
through. In addition, the termination point must be at
least 1 foot (0.3m) above grade or above the snow
line, more than 6 feet (1.8m) from the combustion air
inlet of another appliance, at least 4 feet (1.2m)
below, 4 feet (1.2m) horizontally from, or 1 foot
(0.3m) above any door, window or gravity air inlet
into any building, and more than 3 feet (0.91m) from
and not directly above, any gas meter or service
regulator. See Figures 8 and 9 and Table 3.
Table 3
Vent Systems - Termination Clearance Requirements
Minimum Clearances for
Structure Termination Locations
4 feet below
Door, window or any gravity air inlet 4 feet horizontally
1 foot above
Forced air inlet within 10 ft. 3 feet above
Adjoining building or parapet 6 feet
Adjacent public walkways 7 feet above grade
Figure 6 - Concentric Vent Box

13
Figure 7 - Vertical Intake/Vent Installation
Figure 6A - Concentric Vent Installation

14
Figure 8 - Horizontal Intake/Vent Installation
Figure 9 - Horizontal Intake/Vent Installation
VENTING (continued)
Vent Terminal
(1.8M Min.)
Adjacent Building
D 3330
6'-0" Min.
(0.9M Min.)
3'-0" Min.
Building Overhang

15
VENTING (continued)
VERTICAL TERMINATION
Select location on roof for vent terminal, ensuring
adequate space inside the building/structure for
concentric vent box. Terminal must be at least 6 feet
(1.8m) from any wall or adjoining building. See Figure
7.
Cut a hole through the roof for a 6 inch (152mm)
combustion air pipe. Concentric vent box is to be
suspended from the underside of the roof using
suitable brackets (field supplied). Before mounting box,
cut a length of 6 inch pipe so that dimension A, Figure
6, is equal to the dimension from the top of the box to
the roof surface plus 20 inches or plus maximum
expected snow depth, whichever is greater. Fasten 6
inch pipe to combustion air inlet connection of
concentric vent box and seal joint. Insert pipe through
roof and fasten vent box in place. Flash and/or caulk 6
inch pipe to roof. Install inlet air screen assembly and
fasten to 6 inch pipe with screws. Insert a 5 foot length
of Type B vent pipe through the 4-1/2 inch openings
with the "UP" arrow pointing up. Position the pipe to
extend 12 inches beyond the inlet air screen. Secure
the Type B vent pipe in position by drilling three small
equally spaced holes through the collar of the
concentric vent box and inserting sheet metal screws.
Install deflector disk on Type B vent pipe 2-1/2 inches
above inlet air screen and fasten with screws. Seal joint
between deflector disk and pipe with silicone sealant.
Install vent terminal on top of Type B vent pipe, fasten
with screws and seal joint.
Connect flue pipe and combustion air pipe from
concentric vent box to unit, following instructions on
pages 11 and 12. Joint between Type B vent pipe and
single wall vent pipe must be sealed with high
temperature silicone sealant. (See Figure 6A) Collars
on unit and on concentric vent box are sized so that
crimped ends of combustion air pipes go toward the
unit and crimped ends of flue pipes go away from the
unit.
HORIZONTAL TERMINATION
Select a location on outside wall for vent terminal. In
most applications, the terminal should be on level with
the flue outlet of the unit less a 1/4 inch per foot pitch
for condensate drainage toward the outside of the
building. See Figure 8.
The location of the vent terminal must be in accordance
with the National Fuel Gas Code ANSI Z223.1 in the
U.S. or the Natural Gas Installation Code CAN/CGA-
B149.1 or the Propane Gas Installation Code CAN/
CGA-149.2 in Canada. See Table 3 for minimum
clearances. In Canada, a vent shall not terminate
above a meter/regulator assembly within 3 feet (.9m)
horizontally of the vertical centerline of the regulator
nor within 6 feet (1.8m) of any gas service regulator
vent outlet.
Cut a hole through the wall for a 6 inch (152mm)
combustion air pipe. Install thimble if required by local
codes or type of wall construction. Concentric vent box
may be fastened directly to wall or spaced away from
wall using suitable brackets (field supplied). Cut a
length of 6 inch pipe so that it will protrude 4 inches
(102mm) through the wall when the box is mounted in
position. Fasten pipe to box with sheet metal screws,
using at least three screws per joint. Seal joint with
silicone sealant. Insert pipe through wall and fasten
adapter box in place so that the pipe pitches downward
1/4 inch per foot (21mm/m) toward the outside. Flash
and/or caulk 6 inch pipe on outside wall. Install inlet air
screen assembly and fasten to 6 inch pipe with screws.
Insert a 3 foot length of 4 inch Type B vent pipe
through the 4-1/2 inch openings with the "UP" arrow
pointing toward the outside. Position the pipe to extend
12 inches beyond the inlet air screen. Secure the Type
B vent pipe in position by drilling three small equally
spaced holes through the collar of the concentric vent
box and inserting sheet metal screws. Install deflector
disk on Type B vent pipe 2-1/2 inches (63.5mm) from
inlet air screen and fasten with screws. Install vent
terminal on end of Type B vent pipe, fasten with screws
and seal joint.
Connect flue pipe and combustion air pipe from
concentric vent box to unit, following instructions on
pages 11 and 12. Joint between Type B vent pipe and
single wall vent pipe must be sealed with high
temperature silicone sealant. (See Figure 6A) Collars
on unit and on concentric vent box are sized so that
crimped ends of combustion air pipes go toward the
unit and crimped ends of flue pipes go away from the
unit.

16
OPERATION
SEPARATED COMBUSTION POWER VENTED UNITS
DIRECT SPARK IGNITION
CAUTION: Never operate the unit beyond the
specified limits or severe damage to and or
premature failure of the unit will result!
EXPLANATION OF CONTROLS (see Figure 10)
1. Each Separated Combustion Unit Heater comes
equipped with a power vent system that consists of a
power venter motor and blower, pressure switch,
sealed combustion chamber and sealed flue collector.
CAUTION: The addition of external draft hoods or
power venters is not permitted. Addition of such
devices may cause severe unit malfunction or failure!
2. The power venter motor is energized by the room
thermostat through the integrated control board when
a demand for heat is sensed. The pressure switch
measures the pressure differential between the air
inlet and exhaust vent systems. If the differential is
correct, the unit begins it’s pre-purge timing.
Under no conditions is the unit to
be fired if the power venter is not operable or
severe personal injury or death may occur!
3. The direct ignition system consists of an ignition
control module and a gas valve. When the pre-
purge period ends, the spark ignition system is
energized, and the gas valve opens to supply gas
to the burners. When the thermostat is satisfied,
the vent system is de-energized and the valve closes
to stop the flow of gas to the unit.
4. The limit switch interrupts the flow of electric current
to the control board, interrupting the flow of gas to the
gas valve if the unit heater becomes overheated.
5. Once the thermostat is satisfied, or the
limit switch interrupts the flow of electric
current to the control board, the unit will
begin a post-purge period. When the post-
purge period ends, the power venter motor
is de-energized.
6. The fan operation is delayed 30 seconds
once the thermostat is closed, and
continues operation for 30 seconds after
the thermostat
opens.
NOTICE: The start-up fan delay must not
exceed 30 seconds from a cold start.
7. The wall thermostat, supplied optionally, is a
temperature sensitive switch that operates the vent
and ignition system to control the temperature of
the space being heated.
NOTICE: The thermostat must be mounted on a
vertical, vibration-free surface free from air currents
and in accordance with the furnished instructions.
INITIAL LIGHTING
1. Open the manual gas valve in the gas supply line to
the unit heater. Loosen the union in the gas line to
purge it of air. Tighten the union and check for leaks.
Check all pipe joints for leakage
using a soap solution or other approved method.
Never use an open flame or severe personal
injury or death may occur!
2. Open the manual valve on the unit heater.
3. Turn ON the electrical power.
4. The unit should be under the control of the
thermostat. Turn the thermostat to the highest point
and determine that the power venter motor starts
and the burners ignite. Turn the thermostat to the
lowest point and determine that the power venter
motor shuts off and the burners are extinguished.
5. Turn the thermostat to the desired position.
6. See Gas Input Rate and Adjustments sections.
SHUT DOWN
1. Turn the valve selector lever to the “OFF” position.
2. Turn off the electricity.
3. To relight, follow “start-up” instructions.
See Figure 10-15 for parts/identification.
Figure 10

17
2. PROPANE GAS: An exact manifold pressure of
10.0 inches W.C. (2.5 kPa) must be maintained for
proper operation of the unit heater. Follow steps
“A” through “D” above
3. The adjusted manifold pressure should not vary
more than 10% from pressure specified in Table 4.
Table 4 - Main Burner Orifice Schedule*
TUBULAR UNIT HEATER
HIGH ALTITUDE DERATION
This Tubular Unit Heater has been manufactured utilizing
standard burner orifices and a normal manifold pressure
setting as per the specifications shown on your unit
rating plate.
All unit deration must be done through field adjustments
by a qualified technician. Once the proper adjustments
are made in the field, attach label #J17-06459 to the
unit, and record adjusted manifold pressure, altitude of
the unit installation and the technician’s name and date
on the label using a permanent marker. See Table 5.
Refer to Installation Instruction section on Adjustments-
Gas Input Rate for adjusting the manifold pressure.
12
57
18
57
24
57
30
57
PRIMARY AIR SHUTTER ADJUSTMENT
Primary air adjustment is made at the factory. No field adjustments are necessary.
GAS INPUT RATE
Check the gas input rate as follows (Refer to General
Safety Information section for metric conversions).
Never overfire the unit heater, as this
may cause unsatisfactory operation, or shorten the
life of the heater.
1. Turn off all gas appliances that use gas through the
same meter as the unit heater.
2. Turn the gas on to the unit heater.
3. Clock the time in seconds required to burn 1 cubic
foot of gas by checking the gas meter.
4. Insert the time required to burn one cubic foot of
gas into the following formula and compute the input
rate.
3600 (Sec. per Hr.) X BTU/Cu. Ft.
= Input Rate
Time (Sec.)
For example:
Assume the BTU content of one cubic foot of gas is
1000, and that it takes 48 seconds to burn one cubic
foot of gas.
3600 x 1000
= 75,000
48
NOTICE: If the computation exceeds, or is less than
95% of the gas BTU/hr. input rating (see Table 1),
adjust the gas pressure.
Adjust the gas pressure as follows:
1. NATURAL GAS: Best results are obtained when
the unit heater is operating at its full rated input
with the manifold pressure of 3.5 inches W.C. (0.9
kPa). Adjustment of the pressure regulator is not
normally necessary since it is preset at the factory.
However, field adjustment may be made as follows:
a. Attach manometer at the pressure tap plug below
the control outlet.
b. Remove the regulator adjustment screw cap,
located on the combination gas valve.
c. With a small screwdriver, rotate the adjustment
screw counterclockwise to decrease pressure,
or clockwise to increase pressure.
d. Replace regulator adjustment screw cap.
*
INPUT
IN
1000
BTU
2500 BTU/Ft3
(93.1 MJ/m3)
PROPANETYPE OF GAS NATURAL
1075 BTU/Ft3
(40.1 MJ/m3)
3.5" W.C.
(0.87kPA)
10" W.C.
(2.49 kPA)
NO. OF
BURNER
ORIFICES
MANIFOLD
PRESSURE
2
3
4
5
30
45
60
75
FT 3/HR
ORIFICE DRILL
FT 3/HR
ORIFICE DRILL
FT 3/HR
ORIFICE DRILL
FT 3/HR
ORIFICE DRILL
28
49
42
49
56
49
70
49
HEATING VALUE
*This schedule is for units operating at normal altitudes of 2000 ft. (610m)
or less.
When installed in Canada, any references to deration at altitudes in excess
of 2000 ft. (610m) are to be ignored. At altitudes of 2000 to 4500 ft. (610 to
1372m), the unit heaters must be orificed to 90% of the normal altitude
rating, and be so marked in accordance with ETL certification.

18
2,000
2,500
3,000
3,500
4,000
4,500
5,000
5,500
6,000
NATURAL GAS
MAINTENANCE
PERIODIC SERVICE
NOTICE: The heater and vent system should be
checked once a year by a qualified technician.
All Maintenance/Service information should be recorded
accordingly on the Inspection Sheet provided in this
manual.
Open all disconnect switches and
disconnect all electrical and gas supplies and
secure in that position before servicing unit.
Failure to do so may result in personal injury or
death from electrical shock.
Gas tightness of the safety shut-
off valves must be checked on at least an annual
basis.
To check gas tightness of the safety shut-off valves, turn
off the manual valve upstream of the appliance
combination control. Remove the 1/8 inch pipe plug on the
inlet side of the combination control and connect a
manometer to that tapping. Turn the manual valve on to
apply pressure to the combination control. Note the
pressure reading on the manometer, then turn the valve
off. A loss of pressure indicates a leak. If a leak is detected,
use a soap solution to check all threaded connections. If
no leak is found, combination control is faulty and must be
replaced before putting appliance back in service.
Should maintenance be required, perform the following
inspection and service routine:
1. Inspect the area near the unit to be sure that there is
no combustible material located within the minimum
clearance requirements listed in this manual.
Under no circumstances should
combustible material be located within the
clearances specified in this manual. Failure to
provide proper clearance could result in
personal injury or equipment damage from fire.
2. Turn off the manual gas valve and electrical power
to the unit heater.
3. Remove service panel.
4. To clean or replace the burners, remove the four
screws holding the manifold to the burner box and pull
the manifold back slightly to disengage the orifices
from the burners. Remove each burner by holding it
against the tab on the burner bracket, then rotate the
inlet end of the burner toward the fan side of the unit
and slide the burner off the tabs. See Figure 10.
5. With the burners removed, wire brush the inside
surfaces of the heat exchanger.
6. Remove any dirt, dust, or other foreign matter from
the burners using a wire brush and/or compressed
air. Ensure that all parts are unobstructed.
7. Reassemble the unit heater by replacing all parts in
reverse order.
8. Complete the appropriate unit startup procedure as
given in the “Operation” section of this manual. (See
lighting instruction on the unit nameplate).
9. Check the burner adjustment.
10. Check all gas control valves and pipe connections
for leaks.
11 Check the operation of the automatic gas valve by
lowering the setting of the thermostat, stopping the
operation of the gas unit heater. The gas valve
should close tightly, completely extinguishing the
flame on the burners.
12. Inspect and service motor/fan assembly. To maintain
efficient air flow, inspect and clean the fan blades
and guard to prevent buildup of foreign matter.
13. Check lubrication instructions on motor. If oiling is
required, add 3 or 4 drops of electric motor oil as
follows:
a. Light Duty - After 3 years or 25,000 hours of
operation.
b. Average Duty - Annually after 3 years or 8,000
hours of operation.
c. Heavy Duty - Annually after 1 years or at least
1500 hours of operation.
Never over oil the motor or premature
failure may occur!
14. Check and test the operational functions of all safety
devices supplied with your unit.
Manifold
Pressure
(In. W.C.)
*Heating
Value
BTU/Cu. ft.
9.3
9.2
9.0
8.9
8.7
8.5
8.3
8.1
1,927
1,891
1,853
1,817
1,781
1,745
1,709
1,673
2.9
2.8
2.8
2.8
2.7
2.6
2.6
2.5
6,500
7,000
7,500
8,000
8,500
9,000
9,500
10,000
802
787
771
756
741
726
711
696
Manifold
Pressure
(In. W.C.)
PROPANE (LP) GAS
*Heating
Value
BTU/Cu. ft.
Altitude
(Feet)
Table 4
Manifold
Pressure
(In. W.C.)
*Heating
Value
BTU/Cu. ft.
10.0
10.0
10.0
10.0
10.0
9.9
9.7
9.6
9.5
2,278
2,237
2,196
2,156
2,116
2,077
2,039
2,000
1,964
3.2
3.2
3.2
3.1
3.1
3.1
3.0
3.0
2.9
948
931
914
897
881
865
849
833
818
Manifold
Pressure
(In. W.C.)
PROPANE (LP) GASNATURAL GAS
*Heating
Value
BTU/Cu. ft.
Altitude
(Feet)
*Notes:
1. Consult local utility for actual heating value.
2. Tables based on heating value of 1,050 BTU/Cu. ft. at sea level.

19
1. Burner orifice to small.
1. Irregular orifice causing whistle or resonance.
2. Excessive gas input.
1. Clogged main burners.
2. Misaligned orifices.
3. Insufficient combustion air.
4. Possibly over fired.
1. Blocked venting.
2. Insufficient combustion air.
3. Blocked heat exchanger.
4. Air leak into combustion chamber
or draft hood.
1. Shut off gas supply immediately!
2. Leaking gas test port on valve.
3. Blocked heat exchanger.
4. Blocked draft hood.
5. Negative pressure in the building.
1. Improper ground.
2. Bad or broken spark cable.
3. Faulty control.
4. Pressure regulator set too low.
5. Main burner orifices dirty.
6. Improper venting.
1. Gas supply is off.
2. No power supply to unit.
3. Thermostat not calling.
4. Defective high limit.
5. Defective drafter prove switch.
6. Loose wiring.
7. Improper ground.
8. Improper thermostat or transformer wiring.
1. Improper venting.
2. Unit under fired.
3. Building too cold.
Table 5 - Tubular Propeller Troubleshooting Guide
1. Check with local gas supplier for proper orifice
size and replace. Refer to “Operation”.
1. Replace orifice.
2. Test and reset manifold pressure.
1. Clean main burner ports.
2. Replace manifold assembly.
3. Insufficient combustion air.
4. Check gas input and manifold pressures.
1. Clean Flue. Refer to “Installation”.
2. Clean combustion air inlet openings.
3. Clean heat exchanger. Refer to “Installation”.
4. Determine cause and repair accordingly.
1. Inspect all gas piping and repair.
2. Check to ensure gas test ports are seated.
3. Clean heat exchanger/flue.
4. Clean flue collector.
5. See “Installation”.
1. Check grounding wires and spark bracket
connections.
2. Inspect spark cable connections and cuts.
3. Check to ensure spark is energized after
pre purge period.
4. Test and reset manifold pressure refer to
“Operations”.
5. Clean or replace orifices.
6. Refer to “Installation”.
1. Open all manual valves “check for leaks”.
2. Turn on power supply, check fuses and
replace if bad.
3. Turn up thermostat, Check for 24v on
terminals R and W1 on terminal strip.
4. Check switch for continuity if open with no
heat present, replace.
5. Check switch operation to ensure
switch closes after draftor purge period.
If it does not make/check tubing
connections/ blockage.
6. Check all wiring per diagram.
7. Check all ground wires and connections.
8. Check both, for wiring according to diagram;
check for 24V at gas valve terminals during
trial for ignition period if present and valve
does not open. Replace valve.
1. Refer to “Installation, Venting”.
2. Check gas supply pressures to unit. Refer
to “Installation”.
3. Refer to “Installation”.
A. Flame pops back.
B. Noisy Flame.
C. Yellow tip flame (some yellow
tipping on LP gas is permissible).
D. Floating flame.
E. Gas odor.
F. Delayed ignition.
G. Failure to ignite.
H. Condensation.
SYMPTOMS POSSIBLE CAUSE(S) CORRECTIVE ACTION

20
1. Thermostat located incorrectly.
2. Improper thermostat wiring.
3. Shorted circuit.
4. Defective sticking gas valve.
5. Excessive gas supply pressure.
1. Loose electrical connections at thermostat
or gas valve.
2. Excessive thermostat heat
anticipator setting.
3. Unit cycling on high limit.
4. Poor thermostat location.
1. Power ventor wheel loose.
2. Power ventor wheel is dirty.
3. Power ventor wheel is rubbing on the housing.
1. Loose electrical connections.
2. Defective motor or overload.
3. Defective control board.
1. Motor overload protection is tripping.
2. Loose wiring or connection.
3. Control board is defective.
1. Control Board is in flame failure mode.
2. Fan improperly wired.
3. Defective board.
1. Incorrect gas input.
2. Heater undersized.
3. Thermostat malfunction.
4. Heater cycling on limit.
5. Incorrect orifice sizes.
1. Unit is over fired.
2. Thermostat malfunction.
3. Heater runs continuously.
Table 5 - Tubular Propeller Troubleshooting Guide (continued)
1. Relocate thermostat away from outside
wall or drafts.
2. Check thermostat circuit for open and close
on terminal strip on heater “R” and “W”.
3. Check thermostat circuit for shorts “staples
piercing wires”.
4. Check for 24v on gas valve terminals when
thermostat is not calling.
5. Refer to “Installation”.
1. Tighten all electrical connections.
2. Adjust heat anticipator setting for longer
cycles. Refer to “Electrical Connection”.
3. Check for proper air supply across heat
exchanger and proper gas supply.
4. Relocate thermostat .
1. Replace or tighten.
2. Clean power ventor wheel.
3. Realign power ventor wheel.
1. Check and tighten wires on fan circuit.
2. Test for 115v on terminal ACB Heat and
“L2” if voltage is present replace motor.
3. Test for 115v on terminal ACB Heat and
“L2“” on the control board, if voltage is not
present 45 seconds after trial for ignition
replace board.
1. Check motor amps against motor name
plate, check voltage, replace if found defective.
2. Check for 115v between motor leads.
3. Check terminal ACB Heat for voltage if
voltage not constant, replace board.
1. Turn 115v power off to the unit, wait 10
seconds and reapply voltage to the unit.
2. Check wiring of fan circuit to wiring diagram.
3. If unit is not calling for heat and board is not
in a flash code mode, replace board.
1. Refer to “Operation”.
2. Is the heater output sized correctly for
heat loss of the space. Has the space
been enlarged.
3. Check thermostat circuit, 24v on terminals
“R” and “W” on terminal strip.
4. Check air movement across heat exchanger.
Check voltage and amps at the fan motor.
Check gas input to ensure unit is not over
fired. Check heat exchanger to ensure unit
is not dirty.
5. Check orifice size, replace if undersized.
1. Refer to “Operation”. Check orifice size.
If too big replace.
2. Check thermostat for operation, to ensure
circuit open and closes.
3. Check wiring per diagram; check
operation at the gas valve, look for
a short in thermostat circuit.
SYMPTOMS POSSIBLE CAUSE(S) CORRECTIVE ACTION
I. Burners will not shut off.
J. Rapid burner cycling.
K. Noisy power ventor.
L. Fan will not run.
M. Fan motor turns on and off
while burner is operating.
N. Fan will not stop.
O. Not enough heat.
P. Too much heat.