Shelter Furnace SF3048 User manual

SHELTER FURNACE
WOOD AND COAL BURNING
OUTDOOR FURNACE
MODEL: SF3048
Manufactured by:
Shelter Furnace
10950 Linpage Place
Saint Louis, MO 63132
1-800-875-4788
MADE IN USA
AUGUST 2014
Revision V
Tested to
UL391 and
CSA B366.1-2011
Standards

1
SHELTER OUTDOOR FURNACE MANUAL
MODEL: SF3048
SAVE THESE INSTRUCTIONS
Congratulations! You have selected the nest quality outdoor wood and coal burning furnace, manufactured with pride in the
USA. Please take a few moments to carefully read the owner’s manual. By taking the time to familiarize yourself with your
new Shelter Furnace, you will be able to look forward to years of trouble-free, dependable service.
Installation:
• First, check local codes. The installation must comply with all local rulings and requirements.
• This furnace is an outdoor hot air furnace and must not be altered in any way.
• This furnace requires a back-up electric generator, 2000 watts minimum, in case of power failure.
• Always have a properly installed and functioning smoke detector installed in your home.
• To prevent accidental injury, do not allow anyone who is unfamiliar with the furnace to operate it.
• Spend time familiarizing yourself with your Shelter Furnace, especially the different settings and the effects they
have on burn patterns. It is impossible to predict how each setting will affect your furnace, due to variations in
conditions, fuels, and temperatures.
• When making plans to install your outdoor furnace, the rst thing you need to think about is the placement of the
unit. Although you can install the Shelter Furnace up to 25 feet from the home, a much shorter distance is
recommended to provide better airow. The furnace has been tested for clearance of 31 inches from the home;
this would give maximum airow and provide the highest efciency.
Transportation Damage
Every effort has been made to ensure that your Shelter Furnace will arrive in perfect condition. Any visible damage should be
noted on the freight bill at the time of delivery. If upon unpacking your furnace, you nd damage has occurred during transit,
notify your store immediately. Your store will advise you what actions must be taken to correct the problem.
Disclaimer Notice
The listed BTU rating of your new Shelter Furnace was obtained using laboratory calculations. The actual BTU output you
experience may vary somewhat depending on the type, condition, and moisture content of the fuel used, damper adjustment,
chimney type and other variables. Therefore, the manufacturer disclaims any guarantee as to the BTU output or capacity of
your furnace. Shelter Furnace disclaims any responsibility for the following: installation of a furnace that has been altered
or modied in any way; installation of the furnace other than as instructed in this manual; installation and or use of any
component or part not approved by Shelter Furnace for use on this furnace. Be sure to complete and return your warranty
card within 30 days of purchase in order to activate warranty coverage on your furnace.
Manufacturer’s Notice
Please be advised that periodic changes are made to improve the furnaces. Therefore the information in this manual may not
be completely applicable to your Shelter Furnace. Please refer to markings on the appliance for additional information.
THIS IS AN OUTDOOR WOOD AND COAL BURNING FURNACE ONLY AND
SHOULD NOT BE ALTERED IN ANY WAY.

2
TABLE OF CONTENTS
General Information 3
Furnace Clearances and Operation 4
Installing Electrical Components 4
Grounding Furnace 5
Installing the Anchor Plate 6
Bypass Damper 7
Chimney Location and Clearances 7
Wood Storage and Care 8
Furnace Installation 9
Hot Air Duct and Cold Air Return Installation 10
Burying Ductwork 10
Types of Installations 11
Central Duct Connections 11
Mobile Home Down Draft Furnace Connection 12
No Ductwork Connection 12
General Operation 13
First Wood Fire 13
Loading Wood 13
First Coal Fire 14
Fuel Recommendations 14
Disposal of Ashes 15
Heat Dump and Fuse Link System 15
Draft Blower and Spin Draft 16
Creosote Formation 16
Creosote Prevention 16
Power Failure 16
Maintaining Your Furnace 17
Furnace Diagram with Parts List 19
Grate System Diagram 21
Blower Motor Assembly Diagram 21
Wiring Diagram 22
Troubleshooting 23
Warranty Information 28
DOUBLE CHECK TO MAKE SURE YOU HAVE RECEIVED ALL OF THE
REQUIRED COMPONENTS. IF YOU FIND THAT THERE IS A PART MISSING,
CALL 1-800-875-4788 FOR FASTEST SERVICE. PLEASE DO NOT GO BACK TO
THE STORE. THE STORE DOES NOT HAVE REPLACEMENT PARTS.

3
General Information
ALWAYS KEEP YOUR WOOD COVERED YEAR ROUND; DRY WOOD WILL PRODUCE MORE BTU OUTPUT AND LONGER BURN
TIMES.
The Shelter Furnace is an airtight central solid fuel outdoor furnace engineered to accommodate the heating requirements of the average
sized home, even during winter’s coldest months. It is constructed of high grade, heavy gauge steel and is continuously welded to assure
the utmost in structural strength. The insulated rebox will accommodate a log up to 34 inches in length. In addition, the heat exchanger
is lined with rebrick to ensure many years of energy efcient service.
The design of the secondary combustion chamber increases fuel efciency by creating a “secondary burn” of smoke and wood gases
before they are vented up the chimney. By sending the gases back through the secondary combustion chamber, less fuel is wasted, the
furnace burns at a higher efciency, and for longer burn times.
The cast iron door is custom tted to provide an airtight seal, greatly extending the burn time and ensuring maximum efciency in fuel
consumption. The heavy-duty cast iron grates aid in convenient ash removal and reduce maintenance; the insulated wrap-around sides
are designed for maximum heat transfer.
For total comfort and convenience, a thermostatically controlled 1800 CFM circulation blower system has been installed. The blower
draws the cold air from the home, across the heat chamber before going through the hot air duct and returning the warm air to your home.
This fully automatic blower furnishes rapid heat disbursement to your home, minimizing recovery time. Average burn time per load of
fuel is 6 to 12 hours depending on wood or coal type and condition, desired temperature within the home and amount of fuel. We have
incorporated all of these features as standard equipment, offering you the most efcient, durable and affordable appliance possible.
Abnormally cold weather could reduce the burn time.
Your Shelter Furnace is designed to be either a supplemental or central heating source for your home. This wood and coal burning
furnace may be installed in parallel with a properly operating electric, gas or oil-red central furnace, listed or certied in accordance with
a nationally recognized safety standard, and within clearances specied on Shelter Furnace nameplate. When in a parallel installation the
static pressure of the central furnace plenum may not exceed 0.15 water column inches and the maximum setting on central furnace limit
switch is 182°F. With the Shelter Furnace in an “Interconnection Arrangement” your furnace should be upstream of the central furnace.
The Shelter Furnace warm air supply should never be connected to return air for the central furnace. A qualied installer should perform
the installation.
This is a wood and coal burning furnace – it cannot be turned “off and on” to control the furnace temperature like gas or electric furnaces.
Once the re is established, it has to burn until it burns itself out.
INCLUDED WITH YOUR SHELTER FURNACE:
1– 10” starter collar
1 – 12” starter collar for cold air return
1 – owner’s manual with warranty card
1 – electrical control kit (shipped on top of furnace)
1 – tube of high-temp silicone caulk
ELECTRICAL CONTROL KIT PARTS:
6 – 1/4”- 20 bolts
2 – 1/4” nuts
23 – #10 green screws with rubber gasket for blower housing cover
4 - #10 x 3/4” screws for fan limit control box
1 – draft blower
1 – cover for fan limit control
1 – fan limit control with wire conduit
1 – blower motor and housing
1 – electrical control box
1 – wall thermostat (you must purchase 2-wire thermostat wire
separately)
1 - #10 x 3/4” screw for conduit clip
1 – blower housing cover
1 – blower housing bottom
4 – U nuts for blower housing
2 – #10-32 machine screws
2 – #10-32 nuts
4 – #10 x 3/4”screws for chimney anchor plate
1 – anchor plate
1 – spare fuse link
3 – 1/4” x 20 x 3/4” bolts

4
Furnace Clearances and Installation
Before beginning your installation, consult with local authorities regarding the codes governing all such installations. DO NOT connect
your Shelter Furnace to a ue that is servicing ANY other appliances.
The Shelter Furnace may be placed outdoors or indoors. If outdoors, it must be placed on a level, non-combustible base, preferably a
4’ x 8’ concrete pad, as close to the home as clearances to combustibles permit – but do not place the furnace more than 25 feet from
the house. The furnace must be connected to a grounded electrical circuit with access to a backup generator (2000 watt minimum). If
installing indoors, your furnace must be placed on a non-combustible oor. Air for combustion must be provided into the room where the
furnace is located. Allow air free access to furnace for combustion and ventilation.
Maintain the following clearances:
• Front = 48 inches
• Rear = 31 inches
• Sides = 12 inches
• Heat Duct = 6 inches for the rst 16 inches from the back of the furnace, and 3 inches beyond
Once you have taken into consideration the local requirements governing the installation and positioning of the furnace, install the
Electrical Control Kit. Open the Electrical Control Kit and conrm that all items were shipped with your Shelter Furnace. IMPORTANT:
ENSURE THE POWER CORD IS PLUGGED INTO A GROUNDED ELECTRICAL SUPPLY. The fan limit control is factory pre-set at
160° as the “ON” temperature setting and 100° as the “OFF” temperature setting. This means when the heat chamber reaches 160°, the
blower will turn on; when the chamber cools, the blower will turn off.
IMPORTANT: FOR TECHNICAL SUPPORT OR CUSTOMER SERVICE ISSUES,
DO NOT RETURN TO THE STORE, CALL SHELTER FURNACE AT 1-800-875-
4788.
Installing Electrical Components:
1. Install the blower onto brackets located on the blower housing base using four 1/4”-20 bolts and four 1/4” U nuts (provided).
2. Caulk the blower housing and attach to back of furnace using two 1/4”- 20 bolts and two 1/4” nuts. (See diagram)
Note: To help in the installation, lay part face down (bracket side down) to allow blower to be assembled.
DETAIL A
SCALE 2 : 1
A
PLACE A 1 4BEAD OF
SILICONE RTV ALONG
DOTTED PATH SHOWN
Place a 1/4 inch bead of high-temp silicone
along dotted path shown

5
3. Align the fan limit control box with the gasket to the 4 holes on the back of the furnace with four #10 x ¾” screws for a watertight seal.
4. GROUND FURNACE TO GROUNDING ROD AND LEG OF FURNACE!
5. Mount blower service cover using 23 #10 screws.
6. Pass the wire conduit through the hole on the blower housing. Reinstall the locking nut on weather tight tting.
7. Mount draft motor to the front of the unit using (3) 3/4” bolts. Pass conduit through tube located on lower right corner. Attach
conduit clip with one #10 x ¾” screw to right inner panel. Insert plug into control center receptacle marked “draft motor.
8. Insert the plug from the fan limit control into the control center receptacle marked “fan limit.”
9. Insert the plug from the blower motor into the control center receptacle marked “blower motor.”
Connect the 10 inch starter collar to the heat supply vent of the furnace. Connect the 12 inch starter collar to the cold air return on the
back of the blower housing base.
NOTE: When installing blower housing to the back of the furnace, we suggest that you support the bottom of the blower housing
approximately 6 ¼ inches from ground level to allow for easier mounting of the blower housing cover.
Hot Air Supply
Blower
Service
Cover
Electrical Control Center
(See Close-Up Diagram)
Fan Limit
Control
Cold Air
Return
Transformer for
Thermostat Wire
Blower
Motor
Draft
Motor
Fan
Limit
STEP 7

6
Chimney Pipe and Anchor Plate:
Class “A” HT 2100 All Fuel 6 inch Chimney Pipe is required for optimum performance and must maintain a 2 inch clearance from
combustibles. The Shelter Furnace will ship with an anchor plate and four #10 ¾” galvanized screws with washers and gaskets. If the
anchor plate provided with your furnace does not t your chimney type, please call our toll free number, 1-800-875-4788 for assistance.
IMPORTANT: Please keep in mind that different chimney manufacturers’ pipe will not interchange with other brands. A tube of high-temp
silicone caulk is included with your furnace. Before using the silicone to install the anchor plate to the top of your Shelter Furnace,
ensure the chimney you purchased will t the anchor plate.
Guy wire brackets are attached to the sides of the Shelter Furnace. A heavy gauge of stainless steel wire can be purchased from your
store to use as guy wire to help support your chimney. Attach the appropriate chimney pipe lengths to the adaptor plate nishing with a
chimney cap. IMPORTANT: Your furnace requires its own chimney system and cannot share a ue with any other appliance. DO NOT
USE GALVANIZED OR BLACK PIPE TO VENT YOUR FURNACE.
INSTALLING THE ANCHOR PLATE:
IMPORTANT: BEFORE YOU FOLLOW THE NEXT STEPS, ENSURE THE ANCHOR PLATE YOU RECEIVE MATCHES YOUR
CHIMNEY PIPE, AS CHIMNEY PIPE IS NOT GENERIC AND WILL NOT INTERCHANGE.
1. Using the diagram below as a guide, caulk the
bottom of the anchor plate around the center pipe
shaft.
2. Install the anchor plate to the top of your furnace using
four #10 3/4” galvanized screws with rubber gaskets.
3. Install the chimney pipe to your outdoor furnace.
4. After all the chimney components are installed including
the cap, follow the diagram below to caulk around the
chimney pipe as well as around the outer edge of the
anchor plate.
PLACE A LINE OF 1
4
DIA HIGH TEMPERATURE
SILICONE CAULK ON CHIMNEY ADAPTOR AS
SHOWN BY DASHED LINES
Place a line of high temperature caulk (1/4
inch diameter) on the chimney adaptor as
shown with dashed line.

7
Chimney Clearances and Installation:
Requires Class “A” HT 2100 All Fuel 6” Chimney.
The furnace requires a minimum of 6 feet of chimney. Maintain the “10/2 Rule” for the chimney – In order to determine proper chimney
height above the roof, measure from the side of the chimney horizontally. As you move up the chimney, the length of the measurement
increases. Once this measurement reaches 10 feet, this height on the chimney is your base height. The chimney must be 2 feet taller
than the base height and the chimney must be 2 feet higher than the peak of the roof. The 2 feet above the base height does not include
the cap. See diagram below.
By denition, “Class A” refers to either a lined masonry chimney or all fuel factory-built chimney. Although experts have expressed
differing opinions as to which system is the best, it is a matter of what you nd most suitable. Regardless of your choice of chimney type,
a minimum 6-inch diameter chimney is needed. In order to create the most effective draft, the chimney size should not exceed 12 inches,
with a maximum .08-inch water column draft. The ue draft can be measured with the use of a draft gage or manometer.
Bypass Damper:
The bypass damper has several purposes: starting the re, improving the efciency, and cleaning the chimney. When starting a re in the
Shelter Furnace, you must pull the rod out for a stronger draft during ignition. Once the re has started, close the bypass, which allows
the secondary combustion chamber to engage, increasing the furnace’s operation to peak efciency. If the bypass rod is not closed
during operation, the furnace’s efciency will be greatly reduced, allowing the heat to escape up the chimney. Finally, when cleaning the
chimney, the rod must be pulled out to allow any build-up in the chimney to fall into the rebox.
THIS UNIT IS NOT TO BE CONNECTED TO A CHIMNEY FLUE THAT SERVES ANOTHER APPLIANCE.
10 FEET
2 FEET MINIMUM
4' X 8'
LEVEL CONCRETE PAD
10 Feet
2 Foot Minimum
4’ x 8’
Level Concrete Pad

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Wood Storage and Care:
KEEP WOOD COVERED AT ALL TIMES. This cannot be over-emphasized. Wood stored/stacked, uncovered, exposed to rain and snow
has a higher moisture content, causing the formation of creosote, excess smoke, and it takes longer to ignite and produces poorer res
with lower sustained BTU output. Unseasoned wood ends up costing more in time trying to achieve and maintain proper temperatures
in the rebox, while using more wood with less heat output. Covering the woodpile will keep it dry and offer you the hottest res with the
greatest BTU output. If you store the wood near your furnace, be sure to maintain proper clearance from the furnace to prevent a re
hazard. DRY WOOD WILL PRODUCE HOTTER FIRES AND INCREASE BTU OUTPUT.
IMPORTANT: FOR TECHNICAL SUPPORT OR CUSTOMER SERVICE ISSUES,
DO NOT RETURN TO THE STORE, CALL SHELTER FURNACE AT 1-800-875-
4788.
The Initial Firing:
Do NOT connect the furnace to your ductwork at this time. Build a small re – DO NOT ll the rebox to full capacity during the initial
ring. Your new furnace has a protective coating of oil or paint on the surface, which could produce smoke or odors during the initial ring
and will burn off. Allow adequate ventilation during this initial, break-in ring to let any odors escape. This initial ring also allows the
metals to cure. After successfully completing the initial ring, you are ready to attach the hot air duct and cold air return to complete your
installation. See diagram below.
A Typical Installation
Warm Air
Cold Air

9
Furnace Installation Reminders
• Installation is to be performed by a qualied installer.
• Always consult local building inspectors for codes concerning the installation of your furnace.
• Always have access to a backup generator, 2000 watt minimum.
• Use Class “A” HT 2100 All Fuel 6 Inch Chimney for your Shelter Furnace.
• Never use galvanized pipe in your ue connection.
• Inspect the ue periodically for structural integrity.
• Clean the ue regularly to prevent creosote accumulation.
• Never use chemicals or gasoline to start or maintain your re.
• Never burn garbage, oil, trash, or gasoline in your furnace.
• Never leave the fuel door or ash drawer open during operation.
• Remove ashes on a daily basis, before ashes reach the grates, to ensure proper air ow.
• Never use wet, unseasoned wood or wood exposed to a recent rainfall. Doing so causes a rapid accumulation of hazardous
creosote, which is a proven cause of ue res.
• Never burn plastics, wood products containing glue, or wood that has been treated with chemical preservatives in your
Shelter Furnace. The combustion of these substances may release harmful, toxic gases.
• NEVER UNPLUG THE FURNACE FROM THE POWER SOURCE. THIS WILL CAUSE THE FURNACE TO OVERHEAT. If it
is too warm in the house, reduce the spin drafts to allow less airow into the rebox; and/or use less fuel.
• Never leave the ash drawer or fuel door open in an attempt to regulate the re. This will overheat the furnace and void
the warranty.
• Do not connect this unit to a chimney ue serving another appliance.
• Refer to nameplate on furnace for additional information.
WARNING: RISK OF FIRE
• DO NOT operate with ue draft exceeding .08 water column inches (19.9 Pa).
• DO NOT store fuel or other combustible materials within marked installation clearances.
• Inspect and clean ues and chimney regularly.
• DO NOT operate your furnace with the fuel door or ash drawer open.
DANGER: Risk of Fire and Explosion. Do not burn garbage, gasoline, naphtha, engine oil, or other ammable liquids/inappropriate
materials.

10
Hot Air Duct and Cold Air Return Installation:
Included with your Shelter Furnace:
• One 10 inch starter collar
• One 12 inch starter collar
If using 10 inch insulated hot air ex duct, it is for indoor use only. Outside the house, you must use 10 inch galvanized pipe, wrapped
with weatherproof UV-jacketed insulation for protection from the sun’s UV rays. The 12 inch return air may be galvanized pipe. The
12 inch return air must be attached to the home so as not to pressurize the home. The warm air supply duct should be constructed of
materials with a minimum temperature rating of 250° Fahrenheit.
NEVER reduce the 10 inch hot air or 12 inch return air, as this will affect the air ow and the furnace will not operate properly.
NEVER draw cold outside air into the blower housing. By doing so, the furnace’s heat chamber will not reach the necessary temperature
to heat the home.
The duct work should be designed so the external static pressure does not exceed .02 water column inches, while developing air
velocities of 600 cu. feet to 1,000 cu. feet per minute in the main trunk duct and 400 cu. feet to 600 cu. feet per minute at the registers.
The heat outlet should never be less than 10 inches round or 79 square inches.
The Shelter Furnace must be installed with a cold air return system. The system must be a minimum of 12 inches to readily transfer the
cold air back to the furnace. If desired, a cold air lter box may be constructed with a minimum opening of 225 square inches.
A basement window is an excellent location for running the hot air duct as well as the for the cold air return. The cold air return is an
integral part of the system and must be used when installing the furnace. Failure to use cold air return will pressurize the home causing
the furnace to not work properly. If a basement window is not available, you may access the home through a window, wall, or crawl
space for both the plenum and air return.
Burying Ductwork:
DO NOT BURY FLEXIBLE DUCT.
To bury the ductwork, use schedule 40 or 80 PVC or black plastic DUAL WALL CULVERT PIPE with smooth inner walls. Dig a trench to
accommodate both the heat duct and the return air duct. The trench must be a minimum of 24 inches deep. To further ensure efciency,
minimize heat loss, and prevent moisture formation, line the trench with 1 inch pink Styrofoam insulation sheeting on the sides and
bottom of the trench. The duct run should not exceed 25 feet. If the run exceeds 25 feet, you run the risk of reducing the furnace’s
efciency and airow.
DO NOT USE FLEXIBLE HOT AIR DUCT INSIDE PVC OR CULVERT PIPE.
ALWAYS KEEP YOUR WOOD COVERED YEAR ROUND. DRY WOOD WILL PRODUCE HIGHER OUTPUT AND A LONGER BURN
TIME.
*BE SURE TO KEEP WOOD COVERED YEAR ROUND!*

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The diagram below shows typical installations through a basement window, crawl space, or wall. Notice that the heat duct and return air
duct do not contain any 90° elbows. The use of 45° or less is advised for proper air delivery.
IF 10 INCH FLEX DUCT IS USED, IT MUST NOT BE EXPOSED TO THE OUTDOORS. IT IS FOR INDOOR USE ONLY.
WARNING: RISK OF FIRE! DO NOT USE ANYTHING OTHER THAN 250° F-RATED FLEX DUCT!
IMPORTANT: FOR TECHNICAL SUPPORT OR CUSTOMER SERVICE
ISSUES, DO NOT RETURN TO THE STORE (THE STORE DOES NOT HAVE
REPLACEMENT PARTS), CALL SHELTER FURNACE AT 1-800-875-4788.
TYPES OF INSTALLATIONS:
Your Shelter Furnace is designed to be a supplemental or central heating source for your home. This wood/coal burning furnace may
be installed in parallel with a properly operating electric, gas, or oil-red central furnace that is listed or certied in accordance with a
nationally recognized safety standard within installation clearances as specied on the Shelter Furnace nameplate. When in a parallel
installation the static pressure of the central furnace plenum may not exceed .15 water column inches, and the maximum setting on
central furnace limit switch is 182° F. With the SF3048 wood and coal burning furnaces in an “Interconnection Arrangement” your Shelter
Furnace should be upstream from the central furnace. The Shelter Furnace warm air supply should never be connected to the return air
for the central furnace. A QUALIFIED INSTALLER SHOULD PERFORM INSTALLATION.
CENTRAL DUCT CONNECTIONS: A qualied professional should do the installation. Maximum run should be 25 feet. A duct run in
excess of 25 feet will greatly restrict the air ow and heat output, therefore is not recommended. When connecting the Shelter Furnace
to a central duct system, avoid 90° elbows. As with any furnace, the more turns and branches in the ducting limit the airow delivery. DO
NOT USE FLEX DUCT OUTSIDE.
Run 10 inch insulated galvanized hot air duct from the outside furnace through a window or wall of the house. Once inside, you may use
250º Fahrenheit rated insulated exible hot air duct to connect the central duct system for the home. When using exible duct inside the
home, it must be pulled tight with no offsets or elbows to prevent turbulence and slowdown airow. Connect the duct with a 45° elbow
or at an angle so the hot air from the Shelter Furnace is delivered down stream. This will ensure proper airow into the duct system.
Avoid delivering the hot air through the air conditioning coil, as this will cause an obstruction, reducing the amount of heat output. DO
NOT REDUCE THE SIZE OF THE HOT AIR DUCT. As with any furnace, longer runs and more turns and branches in the ducting greatly
reduce the airow and heat output. Use of 90° elbows is strongly discouraged.
The 12 inch cold air return duct must run to the house to prevent pressurization of the home. Failure to connect the cold air return will
cause the furnace not to operate. NEVER REDUCE THE SIZE OF THE RETURN. Reducing the size of the cold air return will restrict
the hot air ow and put excess pressure on the blower motor. You may terminate the cold air return where you enter the house. This will
provide adequate circulation within the home. See diagram.
RETURN AIR DUCT
SUPPLY DUCT
OPEN/CLOSE
RETURN DAMPERS
3 PLACES
BACKDRAFT DAMPER Return Air Duct
Backdraft Damper
Open/Close
Return Dampers
3 Places
Supply Duct

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MOBILE HOME DOWN DRAFT FURNACE CONNECTIONS: A qualied professional should do the installation. Maximum duct
run is 25 feet, a duct run in excess of 25 feet will greatly restrict the air ow and heat output and is not recommended. Both the hot air
duct and the cold air return duct may be accessed through the oor in a mobile or modular home. In a mobile home with a down draft
furnace, do not attach the hot air duct from the Shelter Furnace to the hot air plenum, doing so will cause the heat to rise through the
central furnace instead of going through the duct work. Split the hot air supply for the Shelter Furnace by using a “Y” and install one
branch into each of the hot air ducts. Be sure both are pointing downstream. See diagram.
NO DUCT WORK INSTALLATION CONNECTION: A qualied professional should do the installation. Cold air return must be
installed in all cases, even those without ductwork. When there is no duct system to connect to the hot air ex duct, keep in mind:
• You must separate the hot air duct from the cold air return. Ideally, locate each at opposite ends of the home. If you don’t, the
air will not ow evenly throughout the home. This method will work well on homes built on concrete slabs and help create a
good airow.
• In homes with a basement, you may run the hot air duct into the basement and pull the cold air return from the main oor, this
will create a perfect air ow, since hot air rises. The cold air return must be connected, even if the home does not have
ductwork. If you don’t connect the cold air return, the furnace will not be able to heat the home. See diagram.
HOT AIR DUCT FROM
OUTDOOR FURNACE
EXISTING DOWNDRAFT
FURNACE
8 INCH DIAMETER,
MINIMUM
8 INCH DIAMETER,
MINIMUM
8 " BACK DRAFT DAMPER
8" BACK DRAFT DAMPER
10" TO 8"
Y-TEE
Existing Downdraft
Furnace
8” Back Draft Damper
8” Back Draft Damper
8 Inch Diameter
Minimum
8 Inch Diameter
Minimum
10” to 8”
Y-tee
Hot Air Duct from
Outdoor Furnace
HOT AIR
COLD AIR
Hot Air
Cold Air

13
Outside combustion air may be necessary for an indoor installation if:
• The solid-fuel-red appliance does not draw steadily, smells, experiences smoke rollout, burns poorly, or back-drafts whether
or not there is combustion present. Opening a window slightly on a calm day alleviates these symptoms.
• The house is equipped with a well-sealed vapor barrier and tight tting windows, and/or has any powered devices, which
exhaust house air.
• There is excessive condensation on windows in the winter.
• A ventilation system is installed in the house.
CAUTION: HOT SURFACES. KEEP CHILDREN AWAY. DO NOT TOUCH DURING OPERATION.
BURN WOOD AND COAL ONLY!
General Operation:
First Wood Fire:
Set the wall thermostat to 90°F. Check to make sure the spin draft is wide open to allow oxygen into the rebox. Make sure switch on the
wall thermostat is in the HEAT position. Adjust slide cover on draft blower to an opening of approximately ⅜ inches.
Place several crumpled newspapers on the grate with some dry kindling layered on top of the papers, then ignite the newspaper. When
the kindling is burning, add several small pieces of wood, allow wood to fully ignite. After about 20 minutes the re should be established,
allowing you to add more wood – do not overload which would smother the re. Add more wood slowly, so the ames have time to engulf
the fresh wood. Once the re is burning and there is a glowing ember bed, adjust the draft to achieve desired burn pattern. Learning
how to adjust the draft to maintain the desired temperature for your home may take several days. After a short time you will know which
settings and adjustments work best for your home. Set the wall thermostat to the desired home temperature.
Do not over-re the furnace. Over-ring by overloading/over fueling the furnace causes the metal to superheat and expand, then cool
rapidly, which causes cracking, therefore voiding the warranty. Over-ring or abuse can easily be determined upon inspection.
It will take about 40 minutes to establish a bed of hot embers. Once you have achieved the hot ember bed, add larger pieces of rewood
and push the bypass rod all the way in. Within 30 to 40 minutes, adjust the spin draft to obtain optimum performance. Finally adjust the
wall thermostat and draft blower cover to a comfortable setting. See diagram on page 16.
NOTE: Your new Shelter Furnace is capable of producing a very high BTU output. Do not fuel your furnace to capacity upon initial ring.
It’s recommended that you become thoroughly familiar with your Shelter Furnace before operating at full capacity.
The new steel and metal components of the furnace have a protective coating or paint on the surface which could produce an odor during
the break in period. Adequate ventilation within the home and furnace room or area is recommended during the initial ring and break
in period to accommodate this possibility. Your new Shelter Furnace is classied as having airtight construction. This type of design
should enable you to experience an average burn time between 6 and 12 hours per full load of fuel (dry, seasoned hardwood). However,
abnormally cold weather may reduce the burn time somewhat, but if your burn cycle is signicantly less, for instance, 2 to 4 hours, you
are over-ring your furnace. This type of occurrence is usually symptomatic of heat demands in excess of furnace capacity. Contact an
authorized professional to determine if your Shelter Furnace has been improperly sized for your home.
Loading Wood:
When opening the fuel door during operation, always pull the bypass rod all the way out before opening the fuel door, wait 10 seconds
after releasing the rst latch, then open the door the rest of the way. The dual latch system has been incorporated as a safety feature,
designed to reduce the possibility of gaseous ignition. Laboratory testing has determined that when incomplete combustion occurs
the partially spent fuel sometimes concentrates large amounts of potentially hazardous gases within the re chamber. If the door is
opened suddenly under these conditions, the oxygen may combine with these gases and cause ignition referred to as “back ash.” Use
EXTREME CAUTION when opening the fuel door.
When reloading the furnace, spread embers evenly over the grate. Place smaller pieces of wood or coal on the hot embers and layer
larger pieces on top of them. Finally, due to the wide variety of temperature ranges during the winter, you may experience periods when
it is not necessary to fully load the re chamber in order to maintain an overnight burn. Your Shelter Furnace will operate at the highest
efciency by adding fuel in amounts needed to maintain comfortable temperatures in your home.

14
IMPORTANT: FOR TECHNICAL SUPPORT OR CUSTOMER SERVICE
ISSUES, DO NOT RETURN TO THE STORE (THE STORE DOES NOT HAVE
REPLACEMENT PARTS), CALL SHELTER FURNACE AT 1-800-875-4788.
First Coal Fire:
Burning coal is much harder than burning wood. There is more care and work in building and maintaining a coal re than a wood re.
Anthracite is the best coal to burn, due to its long even burn with higher heat output and clean burn quality but is more difcult than
Bituminous coal.
The size of coal is important. “Nut” coal sizes of 4 inches for Bituminous and 2¾ to 4½ inches for Anthracite coal are recommended.
Never use coal other than the sizes recommended. If the coal is too small it will smother the re and if it is too large the coal will not burn
well.
When burning Bituminous coal, start the re with wood (as described above). Always use dry kindling, as this will provide a hotter re
and add small pieces of wood until you get a good hot ember bed. At this point add a small amount of coal. When the coal is hot enough
to ignite, add small amounts at a time, so as not to smother the re. Keep in mind that Bituminous coal will require more maintenance as
this type of coal will produce more soot, requiring more frequent cleaning to prevent buildup.
Also make sure that the spin draft control is wide open to establish the correct burn pattern. When adding coal to Bituminous res always
add coal to the center of the bed creating the cone effect. Bituminous coal is more volatile and adding coal to the center of the bed
causes the ames to drive off the volatile gases. Remember that no two installations and chimney set-ups are the same, so be prepared
to experiment until you achieve the desired results. Always allow enough air to the rebox so that volatile gases are properly burned.
When adding fuel, remember to break up the cone with a poker if it has formed a crust, but be careful to avoid mixing the coal as this
can form clinkers. Shake the grates a couple times so as not to disturb the re. Excessive shaking wastes fuel and exposes the grate to
extreme heat, which will cause warping or burnout. For overnight burn operations, follow the above instructions and adjust the chimney
damper and set the thermostat.
When burning Anthracite coal, start the re with wood (as described above). Add layers of coal making sure not to smother the re,
the third layer should be a little heavier, but should not to extend above 2 inches below the top of the brick in the rebox. Before
adding more fuel, be sure to leave a red spot in the center of the bed. This hot spot will help ignite the gases given off the new charge.
A deep charge will give a more even heat and a longer re. It may take up to a couple hours before the whole bed is fully ignited. When
the re is established and the home is becoming warm, you may adjust the damper. It may still take some experimenting with the wall
thermostat to ensure proper operation, as no two installations are the same. Once the coal bed has reduced to half its original depth it
is time to add fuel to the furnace. At this point pull out the bypass rod and turn up the wall thermostat. This will allow the re to burn off
the accumulated gases. Open the fuel door, using a small rake or hoe pull the coals towards the front of the bed, trying not to disturb the
re too much. Next, add coal to the back, being careful not to seal off the top. Keep the ash drawer cleaned out to ensure good airow.
You may want to start this banking process early in the evening before retiring or before leaving the home so that you may make proper
adjustments after the re is well established.
WARNING: It is unsafe to load any type of coal within 2 inches of the top of the rebrick. Load fuel carefully or damage may result.
NOTE: Do not burn coke, charcoal, highly volatile Bituminous coal, sub Bituminous, lignite or cannel coal (sometimes called channel
coal or candle coal). Never burn wax or chemically processed logs, such as re logs as their use is for replaces only. Please follow all
guidelines in this manual concerning wood and coal burning applications due to safety concerns and to maintain warranty coverage.
BURN WOOD AND COAL ONLY!
Fuel Recommendations:
For the SF3048 model, heat resistant gloves are recommended when loading the furnace. Only use dry, seasoned hardwoods in your
Shelter Furnace rather than high resin woods such as pine. Firewood should be cut at least one full season prior to the time of its
intended use for optimum heat output. Firewood should be stacked to provide a free ow of air between the logs; this allows the wood
to season faster. If wood is stored outdoors, it should be completely covered year round to protect it from moisture and exposure to the
elements. Use extreme caution when opening the ash drawer and fuel door during operation, temperatures can exceed 300° F. Wait at
least 10 seconds after releasing the rst latch, then proceed to the fully open position. The dual latch system has been incorporated as a
safety feature, which was designed to reduce the possibility of gaseous ignition. Heat resistant gloves are recommended when opening

15
the fuel door, regulating the spin draft or emptying the ash pan.
DISPOSAL OF ASHES:
Heat resistant gloves are recommended. In order to remove ashes from your Shelter Furnace, slide the ash drawer to the rear of the
furnace. Remove the ash drawer from the furnace and dump the ashes into a metal container with a tight tting lid. The closed container
of ashes should be placed on a non-combustible oor or on the ground, well away from all combustible materials, pending nal disposal.
If the ashes are disposed of by burial in soil or otherwise locally dispersed, they should be retained in the closed metal container until
all cinders have thoroughly cooled. Remove the ashes from your Shelter Furnace at least once a day, or as often as necessary to
ensure the ashes do not accumulate to the height of the grates. If ash build-up occurs at grate level, it will cause premature failure of
the grate system, voiding the warranty on the grates. Unacceptably high temperatures will result because the ashes have restricted the
ow of cooling air beneath the grates. This ow of air was designed to not only cool the grates, but to also provide warmed air for better
combustion. If the ash level is improperly maintained the rebox will be starved of combustion air, greatly reducing the efciency and heat
output of your Shelter Furnace.
ALWAYS KEEP YOUR WOOD COVERED YEAR ROUND. DRY WOOD WILL PRODUCE A HIGHER BTU OUTPUT AND A LONGER
BURN TIME.
HEAT DUMP AND FUSE LINK SYSTEM:
The Shelter Furnace has a patented automatic safety feature, the Heat Dump Release System. In the case of a power failure, the heat
dump release will open the spring-loaded lid when the internal furnace temperature reaches 370° F. The heat sensitive fuse link, located
within the top of the heat chamber, causes the lid to open, allowing the excess heat to escape. This safety feature is designed to activate
before any extreme heat can damage the furnace.
In the case of a power failure, connect your Shelter Furnace to a generator immediately. If the heat dump release lid should open, do
not continue to burn the furnace. DO NOT UNPLUG THE FURNACE. Close the draft dampers and set the wall thermostat to the lowest
possible temperature. DO NOT add fuel (either wood or coal), which will allow the re to die. Pull out by pass rod. After the electricity is
restored, replace the fuse link before resuming normal operation.
Caution: If your heat dump opens without a power failure here is a list of possible reasons:
1). Too many elbows in your duct runs
2). Reducing the size of your duct runs
3). Running your gas/electric furnace blower in the on position.
This will create resistance in the hot air duct run thus causing the fuselink to melt under normal operating conditions without a power
failure.
REPLACING THE FUSE LINK: Remove the hex nut on top of the release lid and pull the bolt down through the lid. Remove the
separated fuse link pieces and connect the new fuse link to the shaft inside the furnace heat chamber. Connect the other end of the
fuse link to the bolt that goes through the lid. Feed the bolt through the lid and replace the hex nut onto the bolt on top of the lid. As a
precaution, always have a replacement fuse link on hand.
WARNING: Never disengage the patented Heat Dump Fuse Link feature. This will void all warranties. Never put anything on top of the
release lid. The area must be kept free of any obstructions. A visual inspection by factory personnel can easily determine if the proper
steps were taken if a furnace over-heats. If the furnace is found to have been deliberately improperly operated, all warranties will be void.
OPEN
CLOSED

16
To order a replacement Fuse Link (Part # FCFL370): call 1-800-875-4788.
One replacement fuse link was included in the hardware pack for your furnace.
Draft Blower and Spin Draft:
The front draft blower plays an important role in the operation of your Shelter Furnace. When the wall thermostat calls for heat, the draft
motor turns on and supplies fresh air into the rebox producing a hotter re, which in turn provides more heat in the heat chamber. The
heat is then sent through the duct system throughout your home. When the wall thermostat temperature is met, the draft blower shuts off
until the thermostat calls for heat, beginning the cycle again. The draft blower has a slide cover located on the side of the motor that is
factory preset, with an opening of approximately 3/8”. The cover should be fully closed only when there is a power failure and electricity
is lost. With the cover closed, no air is introduced into the rebox, then the re dies, preventing the furnace from possible overheating
and damage. The manual combustion air spin damper control on the ash drawer should be set with a 1/8 inch gap. To begin, adjust
slowly by making 1 rotation at a time to nd the correct air setting.
Creosote Formation and Need for Removal:
When wood is burned slowly, it produces compounds in exhaust smoke, which combine with expelled moisture to form creosote. The
creosote vapors condense in the relatively cooled chimney ue of a slow burning re. As a result, creosote residue accumulates on the
ue lining. When ignited, this creosote makes an extremely dangerous re in the chimney. The chimney connector and the chimney
should be inspected at least twice monthly during the heating season to determine if a creosote build-up has occurred. If creosote has
accumulated it should be removed to reduce risk of a chimney re.
Creosote Prevention:
To help prevent the formation of creosote within the ue, ALWAYS BURN DRY, SEASONED WOOD. Dry wood burns hotter, allowing ue
gases to maintain temperatures above 212°F which should reduce the formation of creosote in the chimney. If the ue gas temperature
falls below 212°F, condensation occurs causing creosote formation and accumulation within the chimney.
As an added precaution, periodic chimney inspections are recommended during the heating season to determine if creosote formation
has occurred. For safety and efciency, it is recommended that the chimney system be inspected and cleaned prior to each heating
season.
*BE SURE TO KEEP WOOD COVERED YEAR ROUND!*
slide cover to
make adjustment

17
Power Failure:
In case of power failure, to prevent your Shelter Furnace from over-heating and causing damage to the electrical components, follow
these steps:
• Ensure that the bypass rod is pulled out, allowing heat to go up the chimney.
• Close the spin damper control on the ash drawer.
• Close the slide cover on the side of the draft motor.
• Do NOT add more fuel (coal or wood) to the rebox.
There is no warranty on electrical components damaged due to power failure.
CAUTION:
• INSPECT FLUE PIPES, FIREBOX, STOVE PIPE, CHIMNEY AND DRAFT BLOWER JOINTS AND SEALS REGULARLY TO
ENSURE THAT SMOKE AND FLUE GASES ARE NOT DRAWING INTO, AND CIRCULATED BY THE
AIR-CIRCULATION SYSTEM.
• CLEANING OF THE FIREBOX, STOVE PIPE, CHIMNEY AND DRAFT BLOWER, IS ESPECIALLY IMPORTANT
AT THE END OF THE HEATING SEASON TO MINIMIZE CORROSION DURING THE SUMMER MONTHS CAUSED BY
THE ACCUMULATED ASH.
• Do not use chemicals to start the re.
• Do not burn garbage, gasoline, naphtha, engine oil, or other ammable liquids/inappropriate materials.
Maintaining Your Furnace:
At the beginning of each heating season, take time to thoroughly check your furnace and chimney system. Make sure there are no
leaks where the metal panels are joined or at the caulk lines. Should you nd a leak, high-temp silicone will correct the problem. Check
the door for signs of rust. Should rust develop, lightly sand, with sandpaper or steel wool, the surface and follow up with black, high
temperature paint to keep the door looking new. Check the gaskets, if they are frayed and burnt, replace the gasket. Check the rebricks
for breakage or crumbling, and replace as needed. Check the chimney pipe for signs of creosote formation, if you nd creosote,
thoroughly clean the chimney system replacing the chimney cap securely so rain or snow does not run down the chimney into the rebox.
If the cap is removed for any length of time when the furnace is not in use, cover the pipe so no moisture gets into the rebox. Check the
chimney cap for holes or loosened connections, replace and secure as necessary. Check the grates for signs of wear and replace as
needed. Check the heat duct and cold air return to be sure they have not become loose or been damaged. If so, tighten or replace as
needed. Check ductwork for any air leaks. Remove any accumulated ashes at the end of the season. By following these procedures,
your furnace will provide many years of trouble-free service.
IMPORTANT: FOR TECHNICAL SUPPORT OR CUSTOMER SERVICE
ISSUES, DO NOT RETURN TO THE STORE (THE STORE DOES NOT HAVE
REPLACEMENT PARTS), CALL SHELTER FURNACE AT 1-800-875-4788.
ALWAYS:
• Locate the Shelter Furnace on a level, solid, non-combustible surface.
• Follow local codes concerning installation requirements.
• Connect power cord to a grounded 110 outlet.
• Connect cold air return to the house.
• Use Class “A” HT2100 All Fuel 6 inch chimney.
• Follow guidelines within this manual regarding burn procedures.
• Operate furnace with fuel door and ash drawer closed.
• Inspect the furnace several times a year to ensure furnace caulking is adequate.
• Inspect chimney pipe for creosote formation.
• Use dry, seasoned hardwood and always keep your wood covered.
• Have access to a backup generator in case of power failure, minimum of 2000 watts.
NEVER:
• Allow anyone to operate the furnace that is not familiar with the unit.

18
• Operate the furnace with the spin draft wide open unattended.
• Operate with fuel door or ash drawer open.
• Use gasoline, oil, or any other ammable liquid to start or maintain the re.
• Burn garbage, plastic, wood containing glue or wood that has been treated with chemical preservatives.
• Operate your furnace without a backup power supply, or generator.
• Fuel your furnace with wet, unseasoned wood.
• Use 90° elbows when running ductwork.
• Operate the furnace without the chimney attached.
• Alter the furnace in any way.
CAUTION: HOT SURFACES. KEEP CHILDREN AWAY. DO NOT TOUCH DURING OPERATION.
CAUTION:
• INSPECT FLUE PIPES, JOINTS AND SEALS REGULARLY TO ENSURE THAT SMOKE AND FLUE GASES ARE
NOT DRAWING INTO, AND ARE NOT BEING CIRCULATED BY THE AIR-CIRCULATION SYSTEM.
• CLEANING OF THE FIREBOX, STOVE PIPE, CHIMNEY AND DRAFT BLOWER, IS ESPECIALLY IMPORTANT
AT THE END OF THE HEATING SEASON TO MINIMIZE CORROSION DURING THE SUMMER MONTHS CAUSED BY
THE ACCUMULATED ASH.
• Never use chemicals or gasoline to start or maintain your re.
• Do not burn oil, garbage, trash, plastic, or any fuel other than wood or coal in your furnace. Doing so will void the
warranty.
• DO NOT operate your furnace with the fuel bypass rod open; the handle must be pushed all the way in (except
when refueling).
WARNING: – RISK OF FIRE
• DO NOT operate with ue draft exceeding .08 water column inches (19.9 Pa).
• DO NOT store fuel or other combustible materials within marked installation clearances.
• Inspect and clean ues and chimney regularly.
• DO NOT operate your furnace with the fuel door or ash drawer open.
Canadian Requirements for Supplemental/Add-On Furnaces
• DO NOT USE DUCT ELBOWS HAVING AN INSIDE RADIUS OF LESS THAN 6 inches (150mm) ON OIL,
ELECTRIC, OR GAS FURNACES.
• DO NOT CONNECT TO A DOWNFLOW FURNACE.
• DO NOT CONNECT DUCTWORK SO THAT A REVERSE FLOW IS POSSIBLE.
• OPERATE THE GAS/OIL/ELECTRIC/ FURNACE PERIODICALLY TO ENSURE THAT IT WILL OPERATE
SATISFACTORILY WHEN NEEDED.
• CERTIFIED FOR INSTALLATION WITH APPROPRIATE DUCTWORK CONFIGURATIONS ONLY.
• DO NOT RELOCATE OR BYPASS ANY OF THE SAFETY CONTROLS IN THE ORIGINAL GAS/OIL/ELECTRIC
FURNACE INSTALLATION.
• DO NOT CONNECT TO ANY GAS FURNACE THAT HAS NOT BEEN CERTIFIED INITIALLY AS COMPLYING
WITH CAN/CGA-2.3.
• THE OPERATION OF THE GAS FURNACE MUST BE VERIFIED FOR ACCEPTABLE OPERATION BEFORE AND
AFTER INSTALLATION OF THE ADD-ON APPLIANCE BY A GAS FITTER WHO IS RECOGNIZED BY THE
REGULATORY AUTHORITY.
• DO NOT CONNECT TO ANY GAS FURNACE THAT IS NOT EQUIPPED WITH AN AIR-CIRCULATION BLOWER,
OR TO A CHIMNEY OR VENT SERVICING A GAS FURNACE OR GAS APPLIANCE.
The add-on unit should only be installed on a furnace duct system and chimney that are in good operating condition.
On a belt-driven system, blower and motor pulleys may be changed but the electrical current owing through the motor cannot exceed the
nameplate rating. On a direct-drive system, the motor should not be changed, however, the speed of the motor may be increased. The
blower cannot be changed. This equipment should be installed, acceptable to regulatory authority, by experienced licensed personnel.
The installation should comply with requirements of CAN/CSA-B365, and changes to the installation should comply with CSA-B139 (for
oil-red), C22.1 (for electric), or CAN/CGA-B149.1 or CAN/CGA-B149.2 (for gas-red).

Furnace Diagram - SF3048
19
PARTS LIST
DESCRIPTIONQTY
ITEM
FCOS (ASH PAN TRAY)
11
FC0S 1800 SHELL (SHELL)
1
2
SF42-36 (OUTER SIDE PANEL, RIGHT
)
13
FCOS10COLLAR (STARTER COLLAR 1
0")
14
SF42-47 (BLOWER HOUSING BASE)
15
SNGCLR12 (STARTER COLLAR 12")
16
SF42-45 (BLOWER HOUSING COVER
)
17
FCFLC (FAN LIMIT CONTROL BOX)
18
SF42-39 (OUTER BACK PANEL)
19
FC000-78 (INNER TOP PANEL)
1
10
FCH1800 (HINGE)
111
FC000-81 (HEAT DUMP LID INNER P
ANEL)
1
12
SF42-33 (HEAT DUMP LID)
113
FCHDSB (HEAT DUMP SPRING BRAC
KET)
514
FCFLAB(MACHINE SCREW)
115
SF42-40 (TOP OUTER PANEL)
116
FC000-74 (TOP PANEL C CHANNEL)
117
FC000-75(LEFT AND RIGHT INNER P
ANEL)
218
SF42-37 (OUTER SIDE PANEL, LEFT)
1
19
SFFDA2 (FUEL DOOR ASSEMBLY)
120
SF42-41 (DOOR SKIN)
121
FCDB (DRAFT BLOWER, 50 CFM)
1
22
1
2
18
3
4
5
6
7
8
9
10
11
12
13
15
16
17
18
19
20
22
21
14