Harman SF1500A Installation instructions

3-90-70744R11_05/13
R1
SAFETY NOTICE
PLEASE READ THIS ENTIRE MANUAL BEFORE YOU INSTALL AND USE YOUR HEATING APPLIANCE. FAILURE
TO FOLLOW INSTRUCTIONS MAY RESULT IN PROPERTY DAMAGE, BODILY INJURY, OR EVEN DEATH.
FOR USE IN THE U.S. AND CANADA. NOT SUITABLE FOR INSTALLATION IN MOBILE HOMES
IF THIS FURNACE IS NOT PROPERLY INSTALLED, A HOUSE FIRE MAY RESULT. FOR YOUR SAFETY, FOLLOW
INSTALLATION DIRECTIONS.
CONTACT LOCAL BUILDING OR FIRE OFFICIALS ABOUT RESTRICTIONS AND INSTALLATION INSPECTION
REQUIREMENTS IN YOUR AREA.
CONTACT YOUR LOCAL AUTHORITY (SUCH AS MUNICIPAL BUILDING DEPARTMENT, FIRE DEPARTMENT, FIRE
PREVENTION BUREAU, ETC.) TO DETERMINE THE NEED FOR A PERMIT.
THIS APPLIANCE IS ALSO APPROVED FOR INSTALLATION INTO A SHOP.
SAVE THESE INSTRUCTIONS.
SF1500A, SF2500A, SF2600A, SF3500A
Hot Air Furnaces
Installation & Operating Manual
“Ce manuel est disponible en Français sur demande”

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Table of Contents
Packing List 3
Installation 5
Mounting Blower & Filter Box 7
Wiring 8
Duct Work 11
Operation 11
Safety Tips 13
Chimney Troubleshooting 13
Maintenance 14
Specications    15
Coil Installation 16
Oil Burner Setup 18
Service Parts 19
Warranty 27
= Contains updated information

Harman® Central Heating Appliances are built and
tested to be complete Home Heating solutions. As with
any Central Heat system, a backup heating system may
be required in the event of power outages or during
appliance service or maintenance.

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Packing List - SF2600
Blue Angel Oil Burner- (Sold Separately)
Burner Gasket
Automatic Draft Control
Blower - (Sold Separately)
(2) Blower Brackets - (Included with blower)
Filter Box Kit (3 pieces) + Filter
Fan Control / High Limit
(2) Thermostats
(2) Junction Boxes
Relay
High Limit Snap Disc
(4) 1/4 X 3/4 bolts & (4) Filter Box Mounting Clips
36” Flex Conduit
(1) Straight Conduit Fitting
(1) Elbow Conduit Fitting
Ash Pan
Shaker Handle
Owner’s Manual
Warranty Registration
Filter Box
Mounting Clips
Flex- Conduit and Fittings
Junction Boxes
Ash Pan Shaker Handle
Oil Burner
Oil Burner Gasket
Fan Control /
High Limit
Relay
Snap Disc
Thermostats
Blower Brackets
Filter Box Kit
Blower
Automatic Draft Control
Filter

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Packing List for SF1500, SF2500 & SF3500
Blower Mounting Plate w/ 2= 5/16X3/4 bolts ( SF3500 Only)
Automatic Draft Control
Blower - (Sold Separately)
(2) Blower Brackets - (Included with blower)
Filter Box Kit (3 pieces) + Filter
Fan Control / High Limit
3-Speed Fan Switch (not on SF3500)
Thermostat
Junction Box
Relay
(4) 1/4 X 3/4 bolts & (4) Filter Box Mounting Clips
36” Flex Conduit
(1) Straight Conduit Fitting
(1) Elbow Conduit Fitting
Ash Pan
Shaker Handle
Owner’s Manual
Warranty Registration
Filter Box Kit
Flex Conduit & Fittings
Junction Box
Blower Mount-
SF3500 only
Shaker Handle
Ash Pan
Thermostat
Fan Control /
High Limit
Relay
3-Speed Fan Switch
Blower Brackets
Automatic Draft Control
Blower
Filter Box
Mounting Clips
Filter

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To ensure a safe installation, it is recommended
that this furnace be installed by a qualied
installer.
The sheet metal top and sides can be easily
removed to reduce the chance of dents or scratches
on the painted surfaces.
To remove the sheet metal, rst lift off the top
section. Now, the sides can be removed by lifting
up and out away from the furnace.
To lighten the SF2600, the oil burner heat exchanger
should be removed. Do so by rst removing the
sheet metal as described above. Remove the front
sheetmetalbyrstremovingtheburnercollar.Now
remove the the two long bolts on each side of the
heat exchanger.(Figure B) The entire unit can now
be lifted off and moved separately.
Caution: This furnace must not be installed
closer than 24 inches at the sides and 30 inches
from the rear to combustible materials. The unit
may only be installed on a non-combustible
oor surface such as concrete oor or concrete
pad on dirt oor. The hot air plenum must be a
minimum of 2 inches from the ceiling or other
combustibles above the plenum.
Locate the furnace as close to the chimney as possible while still maintaining
the above clearances. No more than 8 feet of stovepipe should be used,
including two or less 90° elbows. All horizontal runs of pipe should have a
minimum 1/4 in. rise per foot. All stove pipe must be 24 gauge or thicker.
When re-installing the heat exchanger, inspect the gasket around the
furnace opening, and replace if necessary. (Figure A) Place the heat
exchanger in position and secure with the long bolts and nuts. Be sure the
gasket is compressed evenly.
Re-install the sheet metal by sliding the groove on the bottom of each side
panel over the steel lip on the furnace. The top sheet metal piece holds the
sides in place. The SF2600 front cover gets installed by angling the bottom
edgeovertheliponthetopoftherebox.Thesideedgesmustslideinto
thegroovesoneachsideandpushedinushwiththesidesandtop.This
front piece is held in place by the black ring which gets tightened around
the burner pipe. Do not over tighten as this will push the sheet metal in
too far.
Furnace Installation
Figure A
Figure B
Inspect Gasket prior to re-
installing heat exchanger.
(4) 12in. bolts, two on
each side, attach the heat
exchanger to the furnace.

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Bolt the automatic
draft control to the
bottom door. Be sure
to hold the unit straight
while tightening. After
the automatic draft
control is mounted,
the two wires must
be strung through the
exible conduit and
two ttings supplied.
The knockout plug of
the junction box must
be removed to install
the conduit tting.
Check the door of the
automatic draft control
to assure proper
operation. Warning: Keep pieces of wood or coal out of
the draft door opening mechanism, as this could cause the
door to stick.
NOTE: Oil the hinge at the begining of the heating season
with a light oil.
The junction box is best mounted on the side of the furnace
about 1 in. back and 8 in. from the top of the sheet metal
side.(g.CorD)Ifthislocationisinconvenient,anywhere
on the right side will work.
SF1500, SF2500, SF3500.
This gure represents the models; SF1500, SF2500, and
SF3500. It’s intention is to represent the approximate
location of the various controls. This drawing may also be
used as a recommendation for routing of the wiring and
approximate dimension of control spacing.
Please note that this
drawing is for reference
only. Each specic
installation will vary.
Furnace Installation
Installing Wood/Coal High Limit Switch- SF2600 only.
First, install the sheet metal sides as described in the
previous section. Install the snap disc switch into the hole
on the right side sheet metal. Then mount the open backed
junction box around the snap switch. Proceed with wiring as
shown on page 10. Also refer to Figure D. in this section.
Mounting The Oil Burner- SF2600 only.
Remove oil burner unit from it’s box. Loosen the four bolts in
the pipe on the front of the furnace. Insert the nose of the oil
gun into the pipe. Before sliding the oil burner all the way in,
apply the gasket around the nose of the oil gun by wrapping
it around the nose. Next, slide the oil burner into the pipe
and secure it by tightening the four bolts around the collar.
Be sure to tighten the bolts evenly to locate the oil burner
inthecenterofthepipe.Thenalset-upoftheoilburner
should be done by an experienced oil burner technician with
the proper equipment. Refer to the SF2600 wiring diagram
on page 10 and the oil burner manual for proper burner set-
up. There is also a section at the end of this manual with
specicoilburnerinstructions.
Venting Guidelines.
Your Harman hot-air furnace must be vented to it’s own
separateue-lined“ClassA”chimney,notlessthan8”X8”
in size. The chimney must be capable of providing a draft
reading of at least .06” water column on a draft meter, in
order to function properly. The Chimney must be a minimum
of 16 ft. high, and must be two feet higher than anything
within 10 ft. The chimney must also be at least 3 ft. higher
than the point at which it exits or passes by the roof. A
barometricdampermustbeinstalledintheuetoeliminate
excessive draft. Any horizontal sections of connector pipe
must have at least 1/4 in. per foot rise. Limit the number of
elbows to two or less. All joints in the connector pipe must
be secured with sheet metal screws.
Assembly.
Bolt the shaker handle to the block on the lower left side of
the furnace, using the bolts and lock-washers provided.
Bolt the two manual draft controls to the front load door.
Proper installation allows the draft controls to open
approximately 1/2” from the door surface. See Figure 1.

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SF2600.
ThisgurerepresentsthemodelSF2600furnace.It’sintentionistorepresent
the approximate location of the various controls. This drawing may also be used
as a reference for wiring and control spacing. Please note that this drawing is for
referenceonly.Specicinstallationswillvary.
Mounting The Blower And Filter Box
Positionthelterboxbetweenthebracketsontherearofthefurnace,withthe
bottomoftheboxrestingontheangeatthebottomofthefurnace.Insertthe
mountingclipsintothebracketslotstosecurethelterbox.(seeFigure2)Next,
install the blower brackets onto the blower being sure to install the rubber feet
into the brackets. NOTE: On the SF3500, install the blower mount and blower
beforethelterbox.All hardware, brackets, etc. for the blower, will be found
in the carton with the blower.Next,positiontheblowerinthelterbox,centered
behind the inlet hole and allow approximately 1/8 in. space between the rear of
thefurnaceandtheblower outlet. Now,installthelter rail onto thelterbox.
NOTE:Thelterrailisbestinstalledonthesidetowardtheshakerhandle,so
thatany pipesfromthe hot water coil donot interferewith lterinstallation or
removal.
NOTE: Before proceeding with the installation of the access door, it is suggested
that the wiring be completed.
Theaccess door isinstalled by slippingthe angeon the bottomof the access
dooroverthebottomrailofthelterboxopening,thenpushthetopofthedooragainstthetopofthelterboxopeningand
secure with a sheet metal screw.
Furnace Installation
Figure 2
Filter box mounting clips
1/8 in. space between
blower and furnace

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Furnace Installation - Wiring
Wiring
Beforebeginninganywiring,studytheappropriatewiringdiagramforyourunit.AlsoreferbacktoguresCorDforan
example of what the completed job will look like. It is your reponsibility to follow all state and local electrical codes.
Locatethebestplacetoroutethepowerfortheblower,anddrilla7/8”holeinthelterbox.Thisholesizewillaccomodate
a“romex”connector.Attachtheblowerandpowerwiresasshownontheappropriatewiringdiagram.
Once you have the plenum installed, the fan control with high limit switch can be installed. The Fan control/high limit switch
is packaged with a jumper between the two sets of terminals inside. REMOVE THE JUMPER WIRE INSIDE THE FAN
CONTROL. The fan control should be installed in the right side of the plenum and 12 to 18 inches above the top of the
furnace. A separate conduit should be run from the fan control to the junction box.
Mount the thermostat in a central location of the area you want to heat. Run two wires to the junction box, from the heating
terminals on the thermostat. 22 gauge or thicker wire is acceptable.
The next step is to run a 120 volt line from your breaker panel to the junction box. Attach all wires according to the
corresponding wiring diagram, and install the relay into the junction box. DO NOT TURN ON THE BREAKER UNTIL ALL
WIRING IS COMPLETE AND THE RELAY IS SECURED.
SF1500 and SF2500 Wiring Diagram

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SF3500 Wiring Diagram

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SF2600 Wiring Diagram

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Duct Work and Operating Instructions
Duct Work.
This gure shows a typical duct system
layout. Be sure the entire system is properly
sized to provide the correct static pressure
for optimum blower performance. Have
any new duct system designed by a HVAC
professional.
Operating Instructions
Adjusting Automatic Draft Control - In
order for your new furnace to function, the
controls must be properly adjusted. The heat
output is regulated by the automatic draft
control, on the bottom door of the furnace.
Refertotheillustrationsatright;Theelectric
draftmotor(A)opensandclosestheapper
door(B).Theapperdooropenstofeedmoreairtothereandclosestoreducetheairtothe
re.Themaximumairowcanbeadjustedbyturningtheadjusterbolt(C)counter-clockwise
for more air and clockwise for less air. NOTE: To preserve motor life, all adjustments of this
boltshouldbedonewhiletheapperdoorisintheclosedposition.Theidleadjuster(D)
controlstheminimumamountofairthatentersthereboxwhentheapperdoorisclosed.
Adjustment is made by turning the adjuster vertical for zero air, or horizontal for maximum
idle air. It is best to start at a medium setting as shown at right.
Adjusting the fan control- Shut off the power at the circuit breaker before removing the
fan control cover. Make sure the copper jumper (circled below) is removed before using the
furnace. Note the three pointers on the dial. The one on the right is the high limit adjustment.
Pre-setat200degrees,it’sfunctionistoclosetheautomaticdraftcontrolapperdoorifthe
temperature in the plenum reaches 200 degrees. Do not change this setting. The center
pointer adjusts the temperature at which the blower starts. A good initial setting for this is
150 degrees. The pointer on the left is to adjust the temperature at which the blower stops. A good
initial setting for this pointer is 100 to 110 degrees. If it is set too low, the air will feel cool coming
out of the registers at the end of the blower cycle.
Thermostat- Set the thermostat to the desired temperature. When more
heatisneeded,thethermostatopenstheautomaticdraftcontrolapper
door.Thisallowsairintotherebox,whichraisestheoutputofthere.
When the temperature in the plenum reaches the set temperature of the
center pointer on the fan control, the blower will begin blowing heated
air through the ductwork. When the thermostat reaches it’s setpoint, the
automaticdraftcontrolclosestheapperdoor,thus,reducingtheoutput
ofthere.Asthetemperatureintheplenumdropstothesetpointof
theleftpointeronthefancontrol,theblowerwillstop.Asolidfuelre
cannot cease output immediately, therefore, your room temperature
may exceed the thermostat setting at times. You also may notice times
that the blower runs for a short period even though the draft control
isclosed.Again,youcan’t juststopawoodorcoalreinstantly,and
temperature may build enough to run the blower. This is normal and will
be noticed more with coal than with wood.
MED
MAX
ZERO
Return Air Supply Trunk
Plenum
Figure 5
Figure 6
Figure 7

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SF 2600 - Oil Operation as Backup -
The SF 2600 offers a unique option to the homeowner. The
abilitytohaveanefcientoilbackupheatsourcebuiltright
into a wood/coal furnace.
The operation of the oil burner as a backup system is as
simple as setting a thermostat. To use the oil portion of your
furnace as a backup proceed as follows:
1. Set the wood/coal thermostat to the comfort level you
desire.
2. Set the oil thermostat to a level 5 to 10 degrees but not
less than 3 degrees lower than the wood/coal thermostat.
That’s all there is to it. The idea is that when the wood/coal
portion can no longer maintain the level set on that thermostat
the oil portion will come on and maintain the temperature set
on the oil thermostat.
SF 2600 - Oil Operation Only - In the oil only mode, simply
turn the wood/coal thermostat to its lowest setting and select
the comfort level you desire on the oil thermostat. The SF
2600 will now act as a standard oil burner and maintain your
chosen temperature. NOTE: It is recommended that the
wood/coalreinthelowerportionofthefurnacebeoutor
nearlyoutbeforegoingto“oilonly”operation.
Curing Paint -Duringtherstfewhoursofburning,ablue
smoke will be observed rising from the painted surface of
the furnace. It is advisable to increase the amount of fresh
air in the room during this breaking-in period. This may be
achieved by opening doors, windows, etc. Don’t be alarmed.
This is normal.
Starting a Wood Fire - Open the bottom door to increase
the draft. Take about eight sheets of newspaper, crumbled
into balls and place on top of the grates. Next, lay some
nekindlingontopofthepaper.Thiskindlingmustbedry
and no larger than 3/4” diameter, and should be layered in
acriss-crosspatterntoallowgoodairow.Then,laysome
slightly larger pieces (2” diameter) of wood on top of the
kindling. Light the paper at the bottom just inside the door.
Now close loading door and allow kindling and wood to
catchre.Afteraboutveminutes,closethebottomdoor
and open the loading door an inch or two for a few seconds
before opening completely. This method will allow the smoke
toclearawayfromthedooropening.Nowthereshouldbe
well established and ready for some larger wood. Add four
orvepiecesof3”to4”diameterwood.Closeloadingdoor
and open bottom door again. Let burn for about 5 minutes.
Now open loading door using the same method as before,
always closing the bottom door before opening the top door.
Nowloadthereboxwithwoodtothedesiredfullness.All
Harman furnaces may be loaded with wood as full as possible
for high output and long burn time. Then close the door and
allowallthewoodtocatchre.Thebottomdoormayagainbe
opened to speed the process. The object is to get the wood
burning well enough so it will not go out when the automatic
draft shuts back to the idle setting. NOTE: When the bottom
door is open, the automatic draft cannot function to reduce
theamountofairtotherebox.Forthisreason,thefurnace
could overheat.
WARNING: NEVER LEAVE THE BOTTOM DOOR OPEN
WHILE FURNACE IS UNATTENDED!
After the wood is burning well, close the bottom door. The
automatic draft control will now regulate the re. The idle
control(as shownon Fig. 6) on the apper doormust be
adjustedsotheredoesnotgooutoroverheat.Experience
will dictate the best setting. Normally the two manual draft
controls on the loading door are kept closed to burn wood.
Starting A Coal Fire • Use the same procedure as for wood
except do not go to large diameter wood. Use wood about 2”
in diameter maximum. This size will form very hot wood coals
in less time. Here again, the bottom door may be opened to
speed the process. When a substantial bed of red wood coals
are developed, start adding a thin layer of coal. Pea or nut
sizedcoalisbetterforstartingarethanstovecoal.When
therstlayerisburningwithsomeblueame,continueto
add thin layers of coal until there is a solid bed of burning
coal.Leteachlayerburnablueamebeforeaddinganother
layer. Layers can be added until the bed is approximately ten
inchesdeep.Thisisaboutatthetopoftherebrick.Most
usersndthatiftheykeepthetwomanualdraftcontrolsopen
about one quarter turn, it helps keep the gasses burned off.
NOTE; Close the bottom door as soon as the desired coal
bed is made.
Loading - Coal should never be added unless there is a
reasonablyhotre.Thecoalbedshouldbebrightandvig-
orous.Ifthereisburninghotandthereisadeepbedof
coals, full loads of coal can be added at any time. However,
if there is not a deep bed of coals, it is best to add small
amountsofcoalatrst.
Shaking - Shaking should be done only when there is a well-
establishedre.Thefrequencyofshakingwilldependonthe
degree of burning. Shaking should be done whenever the
furnace is refueled. Best results for shaking Harman grates
will occur when short choppy strokes are used rather than
long even strokes.
Operating Instructions

13
3-90-70744R11_05/13
The amount of shaking is critical. Too much will disrupt the
rebedandtoolittlewillrestricttheairow.
Theproperamountnormallyoccurswhenredcoalsrststart
to drop through the grates into the ash pan.
Ashes - Ashes should never be allowed to accumulate in the
ashpitsothattheyinanywayimpedetheowofcombustion
airtothere.Excessashaccumulationcancausethere
to go out and also can cause severe damage to the grates
becauseoftheabsenceofacoolingowofairbeneaththem.
Ashes should be placed in a metal container with a tight
ttinglid.Theclosedcontainerofashesshouldbeplaced
onanoncombustibleoororontheground,wellawayfrom
allcombustiblematerials,pendingnaldisposal.Iftheashes
are disposed of by burial in soil or otherwise locally dispersed,
they should be retained in the closed container [outside the
dwelling) until all cinders have thoroughly cooled.
CAUTION: ASHES SHOULD NEVER BE ALLOWED TO
ACCUMULATE ABOVE THE TOP OF THE ASH PAN.
ASHES IN CONTACT WITH THE BOTTOM OF THE
GRATES ACT AS AN INSULATOR, INTENSIFYING THE
HEAT ON THE GRATES, AND COULD CAUSE THEIR
WARPAGE. WITH AN EXCESSIVE ASH BUILDUP,
PRIMARY COMBUSTION AIR IS RESTRICTED. THUS
THE UNIT’S OUTPUT COULD BE REDUCED.
Coal produces considerably more ash than wood. So the
intervals between emptying are much shorter. For equal
heat output,coal will produce seven to ten times more ash
than wood.
Draft Control Settings - The idle air adjustment on the
apperdoormayneedtobeadjustedslightlylessforcoal
than for wood. Here again, experience will dictate the best
setting. The maximum air adjustment bolt can be set at the
maximum position for quick recov-
ery. When a longer than normal burn time is desired, the
maximum air adjustment can be reduced. Never adjust the
maximumairboltwhentheapperdoorisopened.SeeFig.
6 on page 11.
Safety Tips
When opening the loading door, it should be cracked open
slightly for a few seconds to allow oxygen to burn any gases
that may be present and to allow smoke to be drawn away
from the door.
Whenever the bottom door is open, it should be closed before
opening the loading door. This is to increase draft through
the loading door and prevent excess smoke from escaping.
Thereboxshouldneverbelledwithexcessivecoalsothat
theueexitisblockedorimpededinanyway.Burningcoal
generatescarbonmonoxide.Iftheuegasexitisblocked,
the carbon monoxide can be forced out of the furnace into
the room with possible fatal consequences.
With the exception of start up or increasing heat from a low
re, or removing ashes, the bottom door should be kept
closed. Never install a Harman furnace to a chimney with a
history of down drafts.
KEEP CHILDREN AWAY - MAY CAUSE SERIOUS BURNS.
CAUTION: ALL SURFACES OF FURNACE ARE HOT. DO
NOT TOUCH. KEEP CHILDREN AWAY. SERIOUS BURNS
WILL RESULT IF TOUCHED. THIS IS A HEAT PRODUCING
APPLIANCE.
FUEL/FIRING WARNINGS -
DANGER! FIRE HAZARD! DO NOT USE CHEMICALS
OR FLUIDS TO START OR “FRESHEN UP” A FIRE.
SEVERE BODY BURNS OR A FIRE IN YOUR HOME
COULD RESULT. DO NOT BURN GARBAGE, GASOLINE,
THINNERS, DRAIN OR ENGINE OIL, KEROSENE, OR
FUEL OIL, ETC. AN EXPLOSION, A HOUSE FIRE OR
PERSONAL INJURY COULD RESULT. KEEP ALL SUCH
LIQUIDS WELL AWAY FROM THE FURNACE WHILE IN
USE.
Chimney Problems
Not Enough Draft - Chimney is too low. A chimney should
be two feet higher than anything ten feet around it.
Airmaybeleakinginaroundaloosettingclean-outdoor,
uepipemaynotbetightatjoints,orthemasonrymaybe
defective.
Chimney may be blocked with creosote or bird nests, etc.
Improper sized chimney or stovepipe.
Too many elbows.
Distance of more than eight feet between furnace and
chimney.
Down Drafts - Trees or other topographical barriers may
impede the chimneys operation causing a down draft
condition to exist. This can also be caused by adjacent
buildings or chimneys.
Creosote and Condensation - If creosote or condensation
runs out of the chimney or stovepipe, check the following.
Chimney cap or lining may be defective.
Furnace may be too far from chimney, not allowing the
chimney to get warm.
Wood being burned may be green or wet.
Unit may be too large for home causing wood to be burned
too slow.
Excessive Draft - This can be controlled with a barometric
draft control on the stovepipe.
Operating Instructions/Safety Tips

14
3-90-70744R11_05/13
Maintenance
The spiral chamber is basically self-cleaning. However, if
there is a draft problem and you have been burning wood
for a long time with little heat demand, the spiral chamber
may need cleaning. Soft coal will also require more frequent
cleaning. To clean, remove stovepipe and scrape the
creosote from the front and top of the chamber and remove.
The rear of the chamber will not accumulate creosote.
NOTE: 1/8” to 1/4” of creosote in the spiral chamber is normal.
Creosote can be burned off by burning coal for a few days.
Firebricks may become cracked during the course of normal
operation. A cracked brick that is still in place is still doing its
job and need not be replaced immediately. If a brick is broken
and has fallen out of place, it should be replaced immediately.
TherebrickusedintheHarmanfurnacesareinexpensive
and easy to replace.
The blower manufacturer recommends the blower motor to
be oiled once a year with 10 to 20 drops of light weight oil
[check instructions packed in blower box).
Cleaning Heat-Exchanger (SF2600 Only) -
Remove oil burner by removing four mounting bolts, Burner
can be tied up to ceiling to avoid having to remove the wiring.
Next, remove the collar from the front cover and remove front
coverbytiltingoutfromtoprst.Nowtheheatexchanger
will be exposed. Next, remove the four nuts that hold on the
cover, then remove the cover. This will expose the inside of
the heat exchanger. Remove spirals by simply pulling them
out and clean the tubes with a brush. Reinstall spirals so
theyareushwiththeendofthetubeandreassembleunit
in reverse of disassembly.
Maintenance

15
3-90-70744R11_05/13
Specications
SF1500 SF2500 SF2600 SF3500
Complete Complete Complete Complete
Heating Capacity- square ft. 2200 3200 3200 4200
Approximate BTU Input 90,000 120,000 120,000 170,000
Blower Size 1000 cfm 1000 cfm 1450 cfm 1450 cfm
Automatic Draft Standard Standard Standard Standard
Filter Box & Filter Standard Standard Standard Standard
3-Speed Fan Switch Standard Standard Single Speed Single Speed
Fan Control / High Limit Standard Standard Standard Standard
Thermostat Standard Standard Standard Standard
Domestic Hot Water Coil Optional Optional Optional Optional
Firebox Dimensions - Inches 16Wx22Lx20.5H 18Wx26Lx21.5H 18Wx26Lx21.5H 18Wx30Lx25H
Recommended Log Length 18 in. 22 in. 22 in. 27 in.
Maximum Log Length 22 in. 26 in. 26 in. 30 in.
Flue Size 6 in. 7 in. 7 in. 7 in.
Filter Size 14 X 20 14 X 20 14 X 20 14 X 20
Number of Grates 4 5 5 6
Weight 580 Lbs. 700 Lbs. 900 Lbs. 800 Lbs.
Plenum Dimensions 20 X 20 20 X 20 20 X 25 20 X 25
Clearance to Combustibles- Rear 30 in. 30 in. 30 in. 30 in.
Clearance to combustibles- Side 24 in. 24 in. 24 in. 24 in.
Dimensions:
A: 25 in. 26 in. 28 in. 28 in.
B: 20 in. 20 in. 20 in. 20 in.
C: 46.5 in. 47.5 in. 57 in. 52.5 in.
D: 27.75 in. 31 in. 31 in. 36 in.
E: 20 in. 20 in. 25 in. 25 in.
F: 40 in. 41.75 in. 40.5 in. 45 in.
G: 16.5 in. 16.5 in. 16.5 in. 16.5 in.
H: 44.5 in. 47.5 in. 48 in. 52.5 in.
K: 27.5 in. 27.5 in. 27.5 in. 27.5 in.
H
F
G
D
E
K
A
B
C

16
3-90-70744R11_05/13
Special Instructions
Hot Water Out Cold Water In
Pressure
Relief Valve
Existing Water
Heater Rear Of
Furnace
Automatic
Air Valve
Pressure
Relief Valve
(Must be within
2 feet of coil)
10 Feet Maximum
Drain
Valve
12
33
4
5
Plumbing Diagram For Thermo-Siphon Method - Maximum Distance = 10 Feet
Place one of the supplied nuts on each leg of the coil. Place the coil through the holes on the back of the furnace, and adjust
thenutssothatthepipesstickoutabout1¼to1½inchesfromtherearofthefurnace.Placetheatwashersandgaskets
over each pipe and tighten the nuts. You are now ready to run the piping.
This simple method is the most economical. However, the existing water heater must be less than 10 feet from the furnace.
The water inlet, where the Temperature / Pressure Relief valve is located, must be higher than the top leg of the water coil.
The water heater should be elevated, if necessary, to allow for proper thermo-siphon action.(The method by which hot water
will circulate automatically through the system.)
A. Shut off the water heater and the water supply to it. Drain the tank completely.
B. Remove the Temp. / Presure relief valve and discard. Install a short 3/4 in. nipple and tee (1) along with a new relief valve.
C.run3/4in.coppertubingbetweenthewatertankandthetoplegofthecoil.Installa3/4inventelbowandautomatic“oat
type” air vent (2) in the high point of the line. Within 2 feet of the top leg of the coil, install a 150 lb. pressure relief valve
(5). Run 3/4 in. tubing from the release exit of both relief valves downward (3) so the hot water can escape in the event
of an overheat situation.
D. Remove the drain valve, at the bottom of the tank. Install a short 3/4 in. nipple and tee and re-install the drain valve to
the tee (4). Run 3/4 in. tubing between the drain / tee combination and the lower leg of the water coil. After all of the
connectionsaresecured,rellthewatertank.Turn on the water heater only after the tank has been completely relled.
Coil Installation:

17
3-90-70744R11_05/13
Special Instructions
12
33
45
6
7
8
Hot Water Out
Cold Water In
Temp. / Pressure
Relief Valve
Aquastat, close on rise.
Optional
Automatic
Air Valve
Pressure Relief
Valve - Must be
within 2 ft. of coil
Optional Gate
Valve to Control
Rate of Flow
Circulator Pump
Drain
Valve
Distance between of more than 10 feet
Circulating Pump Method - Distance = 10 Feet or More
This method is used when the water heater tank is more than ten feet away from the furnace or the furnace is on a higher
level than the water heater tank. In addition to a circulator pump, you may want to add a aquastat to thermostatically control
the pump according to water temperature. This is optional and not necessary if the circulator pump is left run continuously.
Anotheroptionisagatevalveplacednearthepumptocontroltherateofwaterow.
A. Shut off the water heater and the water supply to it. Drain the tank completely.
B. Remove the Temp. / Presure relief valve and discard. Install a short 3/4 in. nipple and tee (1) along with a new relief valve.
C. Remove the drain valve, at the bottom of the tank. Install a short 3/4 in. nipple and tee and re-install the drain valve to the
tee (4).
D. Install a circulating pump as shown (6). Run 3/4” copper tubing from the circulating pump to the lower leg of the water
coil.Thisiswheretheoptionalgatevalve(5)canbeinstalledtoregulateow.
E. Install a 3/4 in. tee and a 150 lb. Pressure relief valve (7) in the top leg within two feet of the coil.
F. Complete the 3/4 in. line by running it back to the tee at the top of the water heater tank. Be sure to install the 3/4 in.
vent elbow and automatic air vent (2) at the high point of the line. The optional aquastat can be installed in this line, a
maximum of 6 feet from the furnace. This aquastat must close on rise in temperature and must be hooked up to turn on
the circulator when the water temperature reaches 120° f.
G.Aftersecuringallconnections,rellthetankwithwaterandthen,ONLYTHEN,turnonthepowertothewaterheater.

18
3-90-70744R11_05/13
SF2600 Burner Set Up
7”
12½”
7¾”
12⅞”
SF2600 Oil Burner Setup
Nozzle 80 Degree Solid Cone
Off Cycle Damper Setting (B) No.1 (as low as it goes
Flamelock Setting (A) No. 1
Combustion Air (C) No. 1 to 1¼
Draft - (Inches of water column) .06 to .08
Tests for CO² must be made without a fire in the wood/ coal firebox, and with all doors and draft controls completely closed.
The burner should be fired for several minutes prior to taking a reading. Normal CO² reading is 11 to 12 with a stack
temperature of 300 degrees or less. This would give you an efficiency of 84 to 85 percent.

3-90-70744R11_05/13
Service Parts SF1500A
Beginning Manufacturing Date: N/A
Ending Manufacturing Date: Active
IMPORTANT: THIS IS DATED INFORMATION. When requesting service or replacement
parts for your appliance please provide model number and serial number. All parts listed
in this manual may be ordered from an authorized dealer.
Stocked
at Depot
ITEM DESCRIPTION COMMENTS PART NUMBER
1 Load Door - Cast 4-00-00197P Y
Door Latch 4 Sets 1-00-00036 Y
Gasket, 1/2” Rope (Load Door & Ash Door) 20 Ft 1-00-53500 Y
2 Door Handle - Cast (not as shown in picture) Qty 2 req 4-00-00042 Y
3 Long Shaker Handle Weldment 1-10-01005 Y
Shaker Bar Weldment 5-3/16” 1-10-00668W Y
Shaker Block 2-00-01037-1 Y
Shaker Bracket 2-00-04129F
4 Shaker Handle Mount 2-00-01037-2 Y
5 Ash Door - Cast 4-00-00200-1D
Ash Pan 1-10-16027 Y
6 Automatic Draft Control Assembly 1-10-03375 Y
Draft Control Motor Mount Bracket 2-00-01010B
Draft Motor, 120v 3-20-45338 Y
7 Draft Control - Cast Qty 2 req 4-00-00109-1
Additional service parts on the following page. 1/13
Wood/Coal Hot Air Furnace
1-70-03232
5
2
6
4
7
1
3

3-90-70744R11_05/13
Service Parts SF1500A
Beginning Manufacturing Date: N/A
Ending Manufacturing Date: Active
IMPORTANT: THIS IS DATED INFORMATION. When requesting service or replacement
parts for your appliance please provide model number and serial number. All parts listed
in this manual may be ordered from an authorized dealer.
Stocked
at Depot
ITEM DESCRIPTION COMMENTS PART NUMBER
ADC Cover 2-00-01012P
ADC Hinge 3-31-01004
Blower Assembly 1000cfm 1-10-01006 Y
Replacement Motor (1000 cfm blower) 3-20-36648 Y
Blower Brackets 3-21-22335
Brick 9” X 4-1/2” x 1-1/4” (8 needed) Pkg of 7 1-00-900450125 Y
Set of Cut Brick 1-00-00839 Y
Brick, Used with Reducer, 9" x 4 1/2" x 2 1/2" 3-40-900450250
Brick, Full skid 414 Pcs 3-40-900450-414
Disconnects, Female Pkg of 25 1-00-00959 Y
Door Pins, 3/8 x 1 7/8 Qty 4 req 4-30-00138B
Fan Limit 3-20-23139 Y
Filter Box 1-10-3291
Air Filter-Furnace 14 x 20 x 1 Pkg of 12 3-40-14201-12
Filter Box Mounting Brackets Qty 4 req 2-00-01003
Flex Conduit 7 Ft 1-00-25043 Y
Furnace Kit 1-00-01007-1
Gasket Glue, 32 oz 3-42-4583
Grate Holder 2 - cast Qty 4 req 3-00-00193 Y
Grate Link 4 Hole - cast 4-00-00205D Y
Grate 13 in - Cast (4 needed) 3-00-00207 Y
Hot Water Coil Hardware 3-10-49000
Jacket Side w/o Shaker Hole 2-00-04130-15S
Jacket Side w/Shaker Hole 2-00-00304-15S
Jacket Top 2-00-08117-15S
Relay - Low Voltage 3-20-43393 Y
Spring Handles Pkg of 3 3-40-00086-3-3
Steel Box, 4 x 4 3-20-52171
Straight Hot Water Coil 3-10-49201
Coil Hole Plate Qty 4 req 2-00-04123L
Thermostat - Low Voltage 3-20-12080 Y
Toggle Switch, 3 Speed 3-20-70020 Y
Touch up Paint, Aerosol 3-42-7737