Desa Tech 3500-FACNG Owner's Manual

OWNERS MANUAL

FORCED AIR NATURAL GAS CONSTRUCTION HEATER

Model

3500-FACNG

QUESTIONS?

MISSING / DAMAGED PARTS

Please do not return this product to the store.

If a part is damaged or missing, simply e-mail us at
[e-mail], or visit our website at

STOP

http://allpro-heaters.com, or call our Customer
Service Department at [phone].
We will be happy to assist you!
You can register your heater on line at
http://allpro-heaters.com/warranty.

TABLE OF CONTENTS

HEATER SPECIFICATIONS................................................................................................................ 2

WARNINGS .................................................................................................................................. 2

OPERATING PRECAUTIONS ............................................................................................................. 3

SAFETY PRECAUTIONS .................................................................................................................... 3

ODOR FADE WARNING ...................................................................................................................... 4

OPERATING INSTRUCTIONS ............................................................................................................ 5

SERVICING ......................................................................................................................................... 5

3500-FACNG - PARTS ........................................................................................................................ 6

3500-FACNG - WIRING DIAGRAM ...................................................................................................... 7

WARRANTY......................................................................................................................................... 8

SERVICE CENTERS .......................................................................................................................... 8

INSTRUCTIONS FOR ORDERING PARTS ........................................................................................ 8

WARRANTY REGISTRATION ............................................................................................................. 9

RETAIN THESE INSTRUCTIONS FOR FUTURE REFERENCE

© 2002 Scheu Products Company

Model

3500-FACNG

HEATER SPECIFICATIONS

Type of Gas: For use with Natural Gas Only
Gas Supply Pressure

to regulator Maximum: 60 PSIG (414.0 kPa) Minimum: 15 PSIG (103.5 kPa)
regulator out 20 PSIG (138. kPa)

Electrical Input: 115V, 60 Hz, 1Ø, 3a Minimum Operating Voltage: 100V

Ignition: Direct Spark, interrupted type
Primary Flame Control: Solid State, 10-15 Second Timing

High Temperature Control: 240°F (116°C) Minimum Ambient Temp. Rating 0°F (-17.8°C)

Model: 3500-FACNG

Rating: 175,000 - 350,000 BTU HR

Fuel Consumption: 162.0 - 324.0 CuFt/HR

Fuel Orifice Port No.: 1
Fuel Orifice Port Size: 0.110" (2.79mm)

(51.25 - 102.51 kW)

Heated Air Output: 1400 cfm

(39.64 cmm)

WARNINGS

YOUR SAFETY IS IMPORTANT TO YOU AND TO OTHERS, SO PLEASE

READ THESE INSTRUCTIONS BEFORE YOU OPERATE THIS HEATER.

GENERAL HAZARD WARNING:

FAILURE TO COMPLY WITH THE PRECAUTIONS AND INSTRUCTIONS PROVIDED WITH THIS HEATER, CAN RESULT IN
DEATH, SERIOUS BODILY INJURY AND PROPERTY LOSS OR DAMAGE FROM HAZARDS OF FIRE, EXPLOSION, BURN,
ASPHYXIATION, CARBON MONOXIDE POISONING, AND/OR ELECTRICAL SHOCK.

ONLY PERSONS WHO CAN UNDERSTAND AND FOLLOW THE INSTRUCTIONS SHOULD USE OR SERVICE THIS HEATER.

IF YOU NEED ASSISTANCE OR HEATER INFORMATION SUCH AS AN INSTRUCTIONS MANUAL, LABELS, ETC. CONTACT
THE MANUFACTURER.

WARNING: NOT FOR HOME OR RECREATIONAL VEHICLE USE

WARNING: FIRE, BURN, INHALATION, AND EXPLOSION HAZARD. KEEP SOLID COMBUSTIBLES, SUCH AS
BUILDING MATERIALS, PAPER OR CARDBOARD, A SAFE DISTANCE AWAY FROM THE HEATER AS RECOMMENDED

BY THE INSTRUCTIONS NEVER USE THE HEATER IN SPACES WHICH DO OR MAY CONTAIN VOLATILE OR AIRBORNE
COMBUSTIBLES, OR PRODUCTS SUCH AS GASOLINE, SOLVENTS, PAINT THINNER, DUST PARTICLES OR UNKNOWN
CHEMICALS.

Scheu Products Company, Incorporated

Mail: P.O. Box 250, Upland, CA 91785

Plant: 8855 Baker Ave., Rancho Cucamonga, CA 91730

Telephone: [phone]

www.scheuco.com

[e-mail]

8689

September 2002

Page -2-

OPERATING PRECAUTIONS

SAFETY PRECAUTIONS

This is a natural gas, direct-fired, forced air heater. It's intended
use is primarily temporary heating of buildings under
construction, alteration or repair.

If natural gas leaks from a connection or fitting, it mixes with the
surrounding air, forming a potentially explosive mixture.
Obviously, gas leaks should be avoided, so set up the gas
supply with utmost care. Read enclosed Odor Fade Sheet for
additional information about detecting gas leaks. Leak check
new connections or reconnections with a soap and water
solution and follow all connections instructions herein.

This heater was designed for use as a construction heater in
accordance with ANSI Standard Z83.7/CGA 2.14-2000. Check
with your local fire safety authority if you have any questions
about your applications. Other standards govern the use of fuel
gases and heat producting products in specific applications.
Your local authority can advise you about these.

Direct-Fired means that all of the combustion products enter the
heated space. Even though this heater operates very close to
100 percent combustion efficiency, it still produces small
amounts of carbon monoxide. Carbon monoxide (called CO) is
toxic. We can tolerate small amounts but not a lot. CO can build
up in a heated space and failure to provide adequate ventilation
could result in death. The symptoms of inadequate ventilation
are:

headache dizziness
burning eyes and nose nausea

dry mouth or sore throat
So, be sure to follow advice about ventilation in these operating
instructions.

Forced Air means that a blower or fan pushes the air through
the heater. Proper combustion depends upon this air flow;
therefore, the heater must not be revised, modified or operated
with parts removed or missing. Likewise, safety systems must
not be circumvented or modified in order to operate the heater.

1. Check the heater thoroughly for damage. DO NOT operate a
damaged heater.

2. DO NOT modify the heater or operate a heater which has
been modified from its original condition.

3. Use only natural gas.

4. Provide at least 15 psig. gas pressure to the heater inlet
(regulator inlet) while the heater is operating.

5. Use an appropriate hose or flexible connector not over 10 ft.
(3.05m) in length.

6.Operate the heater only with the 5-20 psi regulator

provided by the factory.

7. For indoor use only. Area must be well ventilated. Figure 1.
(also see "Operating Precautions").

8. If at any time gas odor is detected, IMMEDIATELY
DISCONTINUE operation until the source of gas has been
located and corrected. Read enclosed Odor Fade Sheet
for additional information about detecting gas leaks.

10. Install the heater such that is is not directly exposed to water
spray, rain and/or dripping water.

11. Maintain minimum clearance from normal combustible
material (like paper). Figure 2.

12. Due to the high surface and exhaust temperatures, adults
and children must observe clearances to avoid burns or
clothing ignition.

13. Operate only on a stable, level surface.

14. Do not use with ductwork. Do not restrict inlet or exit.

15. Use only the electrical power specified. The electrical
connection and grounding must comply with National
Electrical Code - ANSI/NFPA 70.

16. Use only a properly grounded 3-prong receptacle and
extension cord.

17. Do not move, handle or service while hot or burning.

18. Use only in accordance with local codes.

When the heater is to be operated in the presence of other
people the user is responsible for properly acquainting those
present with the safety precautions and instructions, and of
the hazards involved.

VENTILATION: Minimum openings required

Heater near floor near ceiling

Infrared ............................................................... 1 ft

Convection (25-VC) ........................................... 1 ft

Convection (All others) ...................................... 2 ft

Radiant ................................................................ 2 ft

Forced air (30K-125K BTU/HR) .......................... 1 ft

Forced air (150-FAST, SPC-150T) .................... 2 ft

Forced air (3500-FACV, SPC-350) .................... 3 ft

Forced air (7000-FACV) .................................... 4 ft

Figure 1

Opening Opening

2

.....................

2

.....................

2

.....................

2

.....................

2

.....................

2

.....................

2

.....................

2

.....................

1 ft
1 ft
2 ft
2 ft
1 ft
2 ft
3 ft
4 ft

2

2

2

2

2

2

2

2

MINIMUM CLEARANCE: From normal combustible material

Figure 2

Radiant Forced Air
Clearance Infrared Convection Forced Air 7000-FACV

From floor ........................................................... 0 ft .............. 0 ft

From outlet .......................................................... 6 ft .............. 10 ft

From sides ................ 3 ft ............ 4 ft ............... 2 ft .............. 3 ft

From top ....................................... 6 ft ............... 3 ft .............. 5 ft

From front ................. 6 ft

From rear .................. 2 ft

Locate 10 ft. from canvas or plastic tarpaulins or similar coverings and
secure them to prevent flapping or movement due to wind action.

Page -3-

Model

3500-FACNG

ODOR FADE WARNING

WARNING

Asphyxiation Hazard

• Do not use this heater for heating human living quarters.

• Do not use in unventilated areas.

• The flow of combustion and ventilation air must not be
obstructed.

• Proper ventilation air must be provided to support the
combustion air requirements of the heater being used.

• Refer to the specification section of the heater’s manual,

FUEL GAS ODOR
LP gas and natural gas have man-made odorants added specifically for detection of fuel gas leaks.
If a gas leak occurs you should be able to smell the fuel gas. Since Propane (LP) is heavier than air you should smell for the gas
odor low to the floor.

• Do not take any action that could ignite the fuel gas. Do not
operate any electrical switches. Do not pull any power
supply or extension cords. Do not light matches or any other
source of flame. Do not use your telephone.

• Get everyone out of the building and away from the area
immediately.

• Close all propane (LP) gas tank or cylinder fuel supply
valves, or the main fuel supply valve located at the meter if
you use natural gas.

• Propane (LP) gas is heavier than air and may settle in low

ANY GAS ODOR IS YOUR SIGNAL TO GO INTO IMMEDIATE ACTION!

heater dataplate, or contact the Scheu Products Company to
determine combustion air ventilation requirements of the
heater.

• Lack of proper ventilation air will lead to improper
combustion.

• Improper combustion can lead to carbon monoxide
poisoning leading to serious injury or death. Symptom of
carbon monoxide poisoning can include headaches
dizziness and difficulty in breathing.

areas. When you have reason to suspect a propane leak,
keep out of all low areas.

• Use your neighbor’s phone and call your fuel gas supplier
and your fire department. Do not re-enter the building or
area.

• Stay out of the building and away from the area until
declared safe by the firefighters and your fuel gas supplier.

• FINALLY, let the fuel gas service person and the firefighters
check for escaped gas. Have them air out the building and
area before you return. Properly trained service people must
repair any leaks, check for further leakages, and then relight
the appliance for you.

ODOR FADING - NO ODOR DETECTED

• Some people cannot smell well. Some people cannot smell
the odor of the man-made chemical added to propane (LP)
or natural gas. You must determine if you can smell the
odorant in these fuel gases.

• Learn to recognize the odor of propane (LP) gas and natural
gas. Local propane (LP) gas dealers will be more than
happy to give you a scratch and sniff pamphlet. Use it to
become familiar with the fuel gas odor.

• Smoking can decrease your ability to smell. Being around
an odor for a period of time can affect your sensitivity to that
particular odor. Odors present in animal confinement
buildings can mask fuel gas odor.

ATTENTION - CRITICAL POINTS TO REMEMBER!

• Propane (LP) gas has a distinctive odor. Learn to recognize
these odors. (Reference Fuel Gas Odor and Odor Fading
sections above.

• Even If you are not property trained in the service and repair
of the heater, ALWAYS be consciously aware of the odors of
propane (LP) gas and natural gas.

• If you have not been properly trained in repair and service of
propane (LP) gas then do not attempt to light heater,
perform service or repairs, or make any adjustments to the
heater on the propane (LP) gas fuel system.

• The odorant in propane (LP) gas and natural gas is

colorless and the intensity of its odor can fade under
some circumstances.

• If there is an underground leak, the movement of gas
through the soil can filter the odorant.

• Propane (LP) gas odor may differ in intensity at different
levels. Since Propane (LP) gas is heavier than air, there
may be more odor at lower levels.

• Always be sensitive to the slightest gas odor. If you
continue to detect any gas odor, no matter how small, treat it
as a serious leak. Immediately go into action as discussed
previously.

• A periodic sniff test around the heater or at the heater’s
joints; i.e. hose, connections, etc., is a good safety practice
under any conditions. If you smell even a small amount of
gas, CONTACT YOUR FUEL GAS SUPPLIER IMMEDIATELY.
DO NOT WAIT!

Page -4-

Model

3500-FACNG

OPERATING INSTRUCTIONS

PREPARING FOR OPERATION

1. Check the heater for possible shipping damage. If any is
found, immediately notify the factory.

2. Follow all of the "Precautions".

3. Install plumbing to a high pressure (15 psi minimum)
source of natural gas, using a minumum 3/8" ID hose or
flexible connector not over 10 ft. (3.05m) in length.

4. Connect the hose to the heater at the 1/4" SAE flare fitting at
the heater inlet.

5. Securely tighten all gas connections.

6. Open the gas cock and check all gas connections with a
soap and water solution. DO NOT USE A FLAME.

7. Connect power cord to well-grounded 115V, 60 Hz, 1Ø
source of power.

8. When using an extension cord, make certain that it is a 3­wire (grounded) cord of proper wire size.

START

1. Slowly open the gas cock at the natural gas source.

2. Plug the power cord into the power source. Turn the heater
thermostat to the temperature desired and heater will ignite
automatically. Adjust regulator to desired output.

STOP

1. Securely close the gas cock at the gas source.

2. Continue to operate heater until all fuel in the hose has
burned.

3. Unplug the power cord.

RESTART AFTER SAFETY SHUTDOWN

1. Securely close the gas cock at the natural gas source.

2. Wait 5 minutes.

3. Restart following "Start" procedure.

MAINTENANCE AND STORAGE

1. The heater should be inspected before each use, and at
least annually by a qualified person.

SERVICING

A hazardous condition may result if a heater is used that has
been modified or is not functioning properly. When the heater is
working properly:

* The flame is contained within the heater.
* The flame is essentially blue with perhaps some yellow

tipping.

* There is no strong disagreeable odor, eye burning or other

physical discomfort.
* There is no smoke or soot internal or external to the heater.
* There are no unplanned or unexplained shut downs of the

heater.

The parts lists and wiring diagram show the heater as it was
constructed. Do not use a heater which is different from that
shown. For this heater, the regulator has a maximum setting of
20 PSIG outlet pressure. If there is any uncertainty about the
regulator setting, have it checked.

A heater which is not working right must be repaired, but only by
a trained, experienced service person. To find the service center
closest to you, visit our website at www.scheuco.com.or call
[phone].

You may also obtain in-warranty or out-of-warranty service by
taking the product to your local service center.

In-warranty products will be repaired with no charge for either
parts or labor. Please include a brief statement indicating date,
place of purchase, the nature of the problem and proof of
purchase.

Out-of-warrranty products will be repaired with a charge for
parts and labor.

Page -5-

3500-FACNG - PARTS

10

13

14

9

8

7

39

12

15

6

5

4

3

2

1

18

19

40

22

41

16

17

11

36

28

6

29

30

27

26

32

Item Part No. Description Qty.

1 3178 Motor Support 1
2 1174 Motor Ass'y 1
3 6229 Spacer, Fan 1
4 6010 Set Screw 2
5 6073 Fan 1
6 6225 Snap Bushing 3
7 7095 Handle Ass'y 1
8 1486 Burner Shell Ass'y 1
9 1546 Burner Tube Ass'y 1
10 1491 Flame Holder Ass'y 1
11 1487 Middle Cylinder 1
12 1663 Grid Ass'y 1
13 3017 Keeper 4
14 7121 Spacer 4
15 7118 Electrode 1
16 6168 High Limit Control Ass'y 1
17 3841 Fuel Nozzle 1
18 6224 Snap Bushing 1
19 6226 Universal Bushing 1
20 1616 Fuel Tube Ass'y 1
21 7343 Fitting, Female Tee 1/4" 1
22 1125 Valve Ass'y 1
23 7355 Fitting, Male Plug, 1/4 MPT 1
24 6265 Fitting, 1/4 FPT x 1/4 MPT 1
25 1734 Thermostat Control Ass'y 1
26 3441 Bracket, Thermostat Mtg. 1
27 1507 Thermostat Knob 1
28 6226 Strain Relief Bushing 1

24

23

25

35

34

20

38

21

37

Item Part No. Description Qty.

29 1036 Power Cord Ass'y 1
30 3180 Inlet Grill Ass'y 1
31 6118 Filter 1/4 Pipe Insert 1
32 1614 Panel, Control Ass'y 1
33 7474 Nipplet 1
34 1711 Regulator 1
35 7475 Fitting 1
36 7808 Flame Control, potted 1
37 1731 Control Box Ass'y 1
38 6144 Ftg, Male Connector 5/16 FLR x 1/4 MPT 1
39 7094 Clip Handle Mounting 2
40 7372 Ftg, Male Connector 5/16 FLR x 1/8 MPT 1
41 7617 Nipple, 2-1/4" 1
* 6070 Loop Clamp, 5/16" 2
* 8689 Manual, Operating Instructions 1
* 8680 Label, BTU Rating 2
* 6384 Label, NG 1
* 6410 Label, Warning, Therm 1
* 7704 Label, Warning 1
* 6373 Label, Fan Rotation 1
* 6374 Label, Electrical Ground 1
* 8683 Label, Logo 1
* 7478 Label, Operating Instructions 1
* 7692 Label, Pressure Gage Port 1
* 8685 Striping 1

* Not shown on exploded view

MODEL

3500-FACNG

WIRING DIAGRAM

GAS

VALVE

CHASSIS

GROUND

MOTOR

B

B

THERMOSTAT

LINE CORD

W

R

Y or B

G

R

B

G

Y or B

W

HI-LIMIT
SWITCH

R

ORIFICE

R

B
W
R
G

ELECTRODE

O

LINE
NEUT
VALVE

GRN

FLAME

CONTROL

COLOR CODE

B BLACK
L BLUE
G GREEN
O ORANGE

If any original wiring as supplied by the heater must be replaced, it must be replaced with type AWG 105° C
wire or its equivalent except as indicated (*type SF2-200, **SGI 250° C).

R RED
W WHITE

LEGEND

TERMINAL BOARD

YY

Y TERMINAL
MALE CONN

Y

FEMALE CONN

WIRING CHART

PART
NO. COLOR LENGTH FROM TO

1721 Red (Hi-Temp) 13" High Limit Switch Valve
1617 Orange 19" Flame Control (Ignition) Electrode
1959 Green 7" Flame Control (Harness) Ground
1959 Red 7" Flame Control (Harness) Terminal Block
1959 White 6" Flame Control (Harness) Terminal Block
1959 Black 6" Flame Control (Harness) Terminal Block

Model

3500-FACNG

WARRANTY

We are pleased that you have selected our product and take
this opportunity to assure you that qualified service facilities are
available if required. With the cooperation of independent
dealers, a nationwide network of authorized servicing dealers is
available for your servicing requirements.

the like and no implied warranty arising from course of dealing
or usage of trade. This warranty will not apply to any product
which has been repaired or altered outside of the California
factory in any respect which in our judgment affects its condition
or operation.

Should your product require servicing, read the section of the
manual entitled “Servicing”.

Who gets the warranty? The warranty is limited to the consumer
who originally purchases the product.

What is covered? This limited warranty covers all imperfections
in workmanship and material.

What is not covered? This limited warranty does not cover
damage resulting from accident, misuse or abuse, lack of
proper maintenance, affixing of any attachments not provided
with the products, or loss of parts. IN NO EVENT SHALL
SCHEU PRODUCTS COMPANY BE LIABLE FOR ANY SPECIAL,
INCIDENTAL OR CONSEQUENTIAL DAMAGES NOR FOR ANY
DAMAGES RESULTING FROM MISUSE OR MODIFICATION OF
THIS PRODUCT.

Registering this heater within 10 days of date of purchase
ensures the buyer the protection as stated on our limited
warranty form.

LIMITED WARRANTY

The company warrants this product to be free from
imperfections in material or workmanship, under normal and
proper use in accordance with instructions of The Company, for
a period of one year from the date of delivery to the buyer. The
Company, at its option, will repair or replace (f.o.b. factory,
California) products returned by the buyer to the factory,
California, transportation prepaid within said one year period
and found by the Company to have imperfections in material or
workmanship.

Some states do not allow the exclusion or limitation of
incidental or consequential damages, so the above limitation or
exclusion may not apply to you. This Warranty gives you specific
legal rights, and you may have other rights which vary from state
to state.

SERVICE CENTERS

Scheu Products Company has over 1,000 service centers
throughout North America. Call [phone] or email
[e-mail] to request the service center nearest you.
Include the Make and model of your heater in any emails.

INSTRUCTIONS FOR ORDERING PARTS

We recommend that only parts supplied by the manufacturer be
used on this unit. A locally purchased part may appear to be
identical, although in reality it might endanger the heater or the
persons operating the heater.

The heater should be serviced only by a trained, experienced
service person.

Read the section on "Servicing" before ordering parts.

For parts orders, call 888-619-7060 or e-mail us at
[e-mail]. Please have the model number of your
heater and the replacement part number when placing your
order.

If a part is damaged or missing, simply e-mail us at
[e-mail], visit our website at scheuco.com, or call
our Technical Support Department at [phone].

Address any Warranty Claims to the Customer Service
Department, Scheu Products Company, Incorporated, P.O. Box
250, Upland, California 91785, or e-mail us at
[e-mail]. Include your name, address and telephone
number and include details concerning the claim. Also, supply
us with the purchase date and the name and address of the
dealer from whom you purchased our product.

The foregoing is the full extent of the responsibility of the
Company. There are no other warranties, express or implied.
Specifically there is no warranty of fitness for a particular
purpose and there is no warranty of merchantability. In no event
shall the Company be liable for delay caused by imperfections,
for consequential damages, or for any charges of the expense
of any nature incurred without its written consent. The cost of
repair or replacement shall be the exclusive remedy for any
breach of warranty. There is no warranty against infringement of

Page -8-

Hand print only. Use black or blue ink pen to fill in this form. Cross or check inside the circle.

Your Information

Warranty Registration

First Name

Mailing Address

City

E-mail Address

Annual house hold income before tax

Age of Purchaser

Your Preferences

Who selected the heater?

Heater will be used by?

How did you learn
about our heater?

<$9,999 $10,000 to $19,999

20-29 years 30-39 years 40-49 years 50-59 years >60 years<20 years

Fold Here

Male

Individual Busi ness

Advertising Relative/friend

Store display

Other

Female Both

Previously owned heater

Last name

-

State

$20,000 to $34,999 $20,000 to $34,999

In choosing your heater the following categories
were:

Features

Portability

Price

Postal code

Somewhat
Important

Important

>$50,000

Very
Important

What prompted you to
buy your heater?

Where will you use the
heater?

Sudden cold weather Emergency backup heat

Replaces old model

Heater on sale

Construction project

Construction site

Shop Patio

Other

Hard to heat location

Other

Warehouse

Product Information

/ /

Date of Purchase (MM/DD/YY)

Brand Name

Cost of Heater ($)

All Pro Universal National Riverside

Store Information where heater was purchased

S/N (Located on a silver label on heater)

Quality

Heat Output

Warranty

Serviceability

Fuel economy

Ease of use

Size

Fold Here

-

Model Number (Located on a black and white label on heater)

Store Name

Type of Store

Hardware Home Center Warehouse Retailer Discount Store Farm Supply

City

Contractor’s Supply Other

Registering this heater within 10 days of purchase ensures the buyer the protection as stated on our limited warranty form.

State

SCHEU PRODUCTS COMPANY, INC

ATTN: MARKETING DEPARTMENT

8855 BAKER AVENUE

RANCHO CUCAMONGA, CA 91730

Visit our website for product information, technical support, customer service, and warranty registration at:
WWW.ALLPRO-HEATERS.COM for All-Pro products or WWW.UNVERISAL-HEATERS.COM for Universal products.