United States Stove 24AF, 24AG, 24AZ User Manual

Wood & Coal Burning Furnace

Owners Manual

Models: 24AF, 24AG, 24AZ

TESTED TO UL 391

All installations must be made in accordance with local and state codes

which may differ from this manual.

UNITED STATES STOVE COMPANY

227 Industrial Park Road

P.O. Box 151

South Pittsburg, TN 37380

USSC Page 1851224C

R

US

CHIMNEY INSTALLATION

Your new furnace must be installed into a "Class A" Chimney only.
This type of chimney consists of a flue lined brick chimney, or an
approved "Class A" all fuel factory built (prefabricated) type. Any
other installation guarantees an immediate fire hazard.

Do not install the furnace into the same chimney serving other appli­ances.

When using 8" flue pipe, the chimney should have an 8" to 10" round
flue liner or 9"x9" square liner.

The chimney should have a minimum height of 3' from the top of the
chimney to the point at which it passes through the roof.

The top of the chimney must be at least 2' higher than the peak or the
highest portion of the roof within 10' horizontally.

A chimney that rises within the house is better insulated than a chim­ney that is located outside the house and exposed to the weather, the
north side of the house is the worst position.

Check manual for proper installation of flue pipe into chimney.

FURNACE INSTALLATION

Install your furnace as close to the chimney as possible with a minimum
of elbows, no more than two and a flue pipe run of no more than 6 feet
horizontally. Also, the flue pipe should contain a 1/2" rise per foot and
NEVER be installed closer than 18" from combustibles.

WOOD BURNING: Install a manual flue pipe draft damper at a safe,
convenient location between your furnace and chimney.

COAL BURNING: Install a barometric damper set at .05 Water Column.

AIR FLOW: Solid Fuel furnaces produce much hotter air than oil or gas
fired appliances so all clearances are mandatory.

AIR DUCT INSTALLATION: This furnace provides a 12" round (113 sq.
in.) opening, because of efficiency and general convenience.

United States Stove Company recommends a Parallel Furnace Installa­tion with direct (ducted) feed or return air to your furnace. NOTE:
Cold air duct intake must be at least 25% larger than hot air duct
outlet.

FURNACE ASSEMBLY

U.S. Stove provides easy step by step pictures, therefore, the fur­nace assembly procedure should be understandable.

FIRING YOUR FURNACE

Start on a conservative basis. Your new furnace, when properly fired
with hard dry wood will achieve approximately 6 to 8 hours of burn time
per load of wood, much longer with coal. If the furnace is being fired
hot constantly with full flames and only provides a 3 hour burn cycle,
the furnace is being overfired. Possibly your heating requirements are
too much for the size of furnace purchased. Certainly allowing your
existing furnace to assist in extremely cold weather is no crime. Re­member, your furnace can be damaged if fired continually at extremely
high temperatures and this procedure will void your warranty.

CAUTION: OVERFIRING YOUR
FURNACE VOIDS WARRANTY.

Page 2 USSC

OVER FIRING

This generally occurs when the following procedures are not fol­lowed, ash door is open (even partially open), the feed door pressure
relief flap is open, the feed door is open or the manual draft spinner
is open. Open the ash and feed doors only when in attendance,
never leave the furnace unattended when doors are open. This
furnace has an automatic draft fan so use the manual draft with a
specific purpose. Also, an overfilled ash drawer can cause grate
warpage, keep ash drawer clean. Don't use furnace if distribution
fan isn't functioning properly, and keep air filter clean. Draft fan
opening should be set at 1/2" open as a point of start, depending on
condition of fuel.

U. S. Stove recommends a very active fire at all times for
maximum results, but only as instructed.

SOME HELPFUL HINTS

•Your furnace will hold logs approximately 2" shorter than the length
of the firebox. Don't force in oversized logs.

•Unsplit, dry logs will provide longer burn time than split logs.

•Don't ever try to burn trash or garbage.

•Keep flue pipe stack temperature between 300 and 400 degrees.
This will reduce creosote build-up. A magnetic surface thermometer
can be obtained from your dealer.

•Weather is the most important determinant in how you operate your
furnace (assuming you have dry wood).

•The colder it is the stronger the draft, warm weather reduces draft.
Set your draft fan rheostat and manual draft accordingly.

•Open manual smoke damper only when starting the fire and when
chimney draft is marginal.

•Always place logs so air can flow between them.

•Shake gently (up to 10 o'clock down to 8 o'clock) don't try to loose
weight shaking down ashes!

•Wood ash is useful as a fertilizer because it contains potassium,
ashes also decrease the acidity of the soil. Coal ashes will provide
good traction on ice or snow, otherwise they are useless.

•Always store ashes in a metal container with a lid.

•Ashes are a good thermal insulator and will keep enough oxygen
away so embers will not burn out.

•Never, never let ashes accumulate up to grate level, this will greatly
reduce the life span of your grate.

•Coal produces much more ash than wood.

•Keep your chimney and flue pipe clean, check monthly.

•Smoke detectors and fire extinguishers should always be a part of
your equipment.

•Never use chemicals or fluids such as gasoline, charcoal lighter, drain
oil or kerosene to light a fire.

•Oil the air fan motors yearly. They do not contain bearings, sleeves
with felt. Therefore keeping fan air clean is more important than
oiling.

•Turn on your regular furnace once every month to keep it tuned up.

•Always shut the furnace down gradually to prevent excessive stress
on steel.

WARPAGE OF STEEL IS COMMON, AGGRESSIVE BUT GENTLE
FIRING CAN MINIMIZE WARPAGE.

•There is no substitute for dry hard wood. Wood requires 6 months
to a year to air dry to 25% moisture content or less.

•Don't throw heavy, wet wood into your Jensen, it could crack the
firebox and bricks.

•Treat your furnace with the proper respect and it will reward you
with much comfort, and a lifetime of central heat.

Welcome...

...to the world of solid fuel heating! Your new furnace has been designed and built
with a high grade of materials and the strictest regard to quality.

Before you start installing your new furnace, take the time to read these installation
and operating instructions. We have prepared them for your benefit to save time and
provide some helpful knowledge on wood and coal burning.

Save the instructions for future use. It won't take long for you to realize the benefit of
solid fuel heating, however, maintenance is the key to a long lasting relationship with
your new furnace. These instructions can help you now as well as in the future.

Note: This owners manual is provided for Forced Air add on furnaces. United States
Stove Company is constantly developing and improving its product line, therefore, we
reserve the right to change specifications without notice.

Table Of Contents

General Rules ..............................................................................................................................................................................4

How It Works ...............................................................................................................................................................................5

Parts List .................................................................................................................................................................................. 6-7

Installation Instructions ........................................................................................................................................................ 8-11

Assembly ..............................................................................................................................................................................12-16

Accessories ................................................................................................................................................................................17

Wiring ................................................................................................................................................................................... 18-23

Trouble Shooting .......................................................................................................................................................................24

Notes .................................................................................................................................................................................... 25-26

Warranty ....................................................................................................................................................................................27

How To Order Repair Parts ......................................................................................................................................................28

USSC Page 3

General Rules

Rules for the Safe Installation and Operation of Your
Furnace...

Check local codes, the installation must comply with strict
conformance in regard to clearances.

The Furnace must be installed on a noncombustible floor.

Connect the furnace to tile lined inside masonry chimney or
approved insulated all fuel prefabricated chimney only.

Keep smoke pipe connection as short as possible, using a
minimum 24 gauge pipe with a minimum 1/2" per foot rise
from the flue collar to the chimney opening.

Be sure there is a sufficient supply of combustion
air to the area where the furnace is to be located.

Do not over draft the furnace! It is designed to operate at
.04 to .06 inches of water column and must be set with a
draft gauge to maintain a steady draft.

Do not use flammable liquids for starting a fire.

Do not store fuel or combustibles near the furnace. Some
areas of the furnace are hot and could cause an explosion
and possible bodily or property damage.

Store all ashes in a metal container with a tight sealing lid
and allow ashes to cool before disposing of them, possibly
a week.

In the event of a chimney fire call the fire depart­ment, then be sure the furnace doors are closed
tightly and the power to the unit is turned off.

The furnace is designed to burn air dried wood and coal at
a predetermined firing rate. Over firing could result in dam­age to the heat exchanger and cause dangerous opera­tion. Over firing occurs when the ash door is left open
during operation or a highly volatile fuel, such as large
amounts of small kindling, is used. Note: This action voids
all warranty.

Follow a regular service and maintenance schedule of the
furnace and chimney for efficient and safe operation.

Do not leave the ash door open when the fire is burning.

Do not let ashes build up closer than 2" to the grate.

With new steel, there is a small amount of oil or dirt on the
metal. You may smell an odor. This is normal during the
first operation. You should assemble the furnace out of
doors and build a small fire in it to "burn off" this dirt and
oil before installing the unit.

During the first few fires, heat may slightly warp
the front and back panels. This is normal and will
not hamper your unit's operation.

Familiarize yourself with the furnace's solid fuel burning
characteristics before leaving unit unattended for long pe­riods of time.

The loading door and ash door must be tightly closed dur­ing furnace operation to insure safety and efficiency.

CAUTION ­The furnace has hot surfaces. Keep Children Away.
Do not touch during operation.

DO NOT CONNECT THIS UNIT TO A CHIMNEY FLUE SERV­ING ANOTHER APPLIANCE.

BURN WOOD OR COAL ONLY IN MODEL 24AF. DO NOT
MIX OTHER THAN THE USE OF WOOD TO START A COAL
FIRE.

DANGER - Risk of Fire or Explosion: Do not burn gar­bage, gasoline, drain oil or other flammable liquids.

WARNING - Risk of Fire:
Do not operate with flue draft exceeding 6 inches
water column.
Do not operate with fuel loading or ash removal
doors open.
Do not store fuel or other combustible material
within marked installation clearances.
Inspect and clean flues and chimney regularly.

This Furnace Must Be Installed By A Qualified Installer.

Page 4 USSC

How...

How Your New Furnace Works

Unlike conventional heating (gas, oil, electric), wood or coal
heating requires more user attention. Your furnace, with
its automatic combustion air blower, alleviates the constant
need for adjusting the burning rate common to other units
on the market. The fire, however, must be started and
subsequent fuel added by the user.

Conventional heating system produce heat only when the
thermostat calls for heat. This way of heating is inefficient
and often leaves part of the home either too hot or too
cold. Your furnace is designed to deliver heat as long as
there is a fire in it. The fire intensity is regulated by the
room thermostat, high or low, the fire continues to pro­duce heat. This heat is continuously distributed throughout
the home by a distribution blower. This constant supply of
heat is uniform and prevents drafts.

WARNING

Note: Improper firing. Wood or coal over firing oc­curs when the ash door is left open during operation
or a highly volatile fuel is used. Coal that exceeds the
fire brick line will cause overfiring...this type of op­eration will immediately void any warranty.

USSC Page 5

23

Parts

FOR MODEL(S): 24AF

2521

27

10
11

27
14

13
16

36

28

38

18
17

4 8 26 22

20
19

6
7

5
9

31

12

15

1

24

23

39

37

34

29
26

33

30 32

Page 6 USSC

35

Parts

KEY PART # DESCRIPTION QTY.

1 69072 FIREBOX WELDMENT 1
2 C97999 WATER COIL COVER GASKET 1

3 24220 INSIDE COVER PLATE 1
N/S C23799 12 x 3/4" TEKS SCREW 3
N/S 83236 1/4-20 x 3/4" HX SCREW 4

4 25085 FEED DOOR 1
N/S 88033 3/8" ROPE GASKET (FEED DOOR) 4.25 FT.
N/S C21390 7/32 x 1 ROLL PIN (FEED DOOR) 2

5 24482 PRESSURE FLAP 1
N/S 88075 3 /4 F L A T R O P E G A S KE T 1 FT.
N/S C21390 7/32 x 1 ROLL PIN (PRESSURE FLAP) 2

6 69077 FEED DOOR HANDLE ASSY. 1

7 83379 1/4-20 x 1 BOLT 1

8 83261 1/4-20 LOCK NUT 1

9 24485 ASH DOOR 1
N/S 88033 3/8 ROPE GASKET 2.29 FT.

10 24486 ASH DOOR HANDLE 1

N/S C21390 7/32 x 1 ROLL PIN (ASH DOOR) 2

11 83379 1/4-20 x 1 BOLT 1
12 83261 1/4-20 LOCK NUT 1
13 24382 SPIN DAMPER 1
14 83471 5/16-18 x 1-3/4" CARR. BOLT 1
15 83423 5/16-18 HEX LOCK NUT 1
16 69068 ASH DRAWER ASSY. 1
17 24501 SMOKE CURTAIN 1
18 83445 1/4-20 x 1-1/4" BOLT 2
19 83261 1/4-20 LOCK NUT 2

FOR MODEL(S): 24AF

20 23787 SMOKE DOOR CLIP 2
21 89799 STUB COLLAR 1
22 24528 DAMPER ROD 1

N/S 83874 1/8 DIA. x 1-1/2" COTTER PIN 1

23 69080 CONTROL CENTER 1
24 69097 FORCED DRAFT BLOWER ASSY. 1
25 80129 THERMOSTAT 1
26 89574 SPRING HANDLE (DAMPER ROD, SHAKER) 2
27 89849 HOOK SPRING HANDLE (FEED, ASH DOOR) 2
28 69082 JUNCTION BOX ASSY. 1
29 69069 SHAKER GRATE HANDLE 1
30 40369 SHAKER GRATE FRAME 2
31 40349 SHAKER GRATE 2
32 40366 FIREBOX LINER 2
33 24496 FRONT HEAT PLATE 1
34 24487 FURNACE HEAT PLATE 1
35 89066 FIREBRICK 10
36 24488 CABINET TOP 1
37 24489 CABINET RIGHT SIDE 1
38 24490 CABINET LEFT SIDE 1
39 C60456 1050 CFM DISTRIBUTION BLOWER 1

USSC Page 7

N/S = NOT SHOWN

Parts

FOR MODEL(S): 24AG, 24AZ

2521

27

10
11

27
14

13
16

434244

4826

6
7

5
9

31

41

22

23

28

38

12
15

40

39

20
19

36

1817

1

24

23

45

37

34

29
26

33

30 32

Page 8 USSC

35

Parts

KEY PART # DESCRIPTION QTY.

1 69315 FIREBOX WELDMENT 1

2 C97999 WATER COIL COVER GASKET 1

3 2422 0 INSIDE COVER PLATE 1

N/S C23799 12 x 3/4" TEKS SCREW 3
N/ S 83236 1/4-20 x 3/4" HX SCREW 4

4 250 85 FEED DOOR 1

N /S 88033 3/8" ROPE GASKET (FEED DOOR) 4.25 FT.
N/S C21390 7/32 x 1 ROLL PIN (FEED DOOR) 2

5 24482 PRESSURE FLAP 1

N / S 8807 5 3/4 FLAT ROPE GASKET 1 FT.
N/S C21390 7/32 x 1 ROLL PIN (PRESSURE FLAP) 2

6 69326B FEED DOOR HANDLE ASSY. 1

7 83379 1/4-20 x 1 BOLT 1

8 83261 1/4-20 LOCK NUT 1

9 24485 ASH DOOR 1

N /S 880 33 3/8 ROPE GASKET 2.29 FT.

10 25047B ASH DOOR HANDLE 1

N/S C21390 7/32 x 1 ROLL PIN (ASH DOOR) 2

11 83379 1/4-20 x 1 BOLT 1
12 83261 1/4-20 LOCK NUT 1
1 3 2438 2 SPIN DAMPER 1
14 83471 5/16-18 x 1-3/4" CARR. BOLT 1
15 83423 5/16-18 HEX LOCK NUT 1
16 69068 ASH DRAWER ASSY. 1
1 7 24501 SMOKE CURTAIN 1
18 83445 1/4-20 x 1-1/4" BOLT 2
19 83261 1/4-20 LOCK NUT 2
20 2 3787 SMOKE DOOR CLIP 2
2 1 8979 9 STUB COLLAR 1
2 2 24528 DAMPER ROD 1

N/ S 83874 1/8 DIA. x 1-1/2" COTTER PIN 1

2 3 69321G CONTROL CENTER 1
* * 69323 CONTROL CENTER (STAINLESS STEEL) 1
24 69097 FORCED DRAFT BLOWER ASSY. 1
2 5 8 0 129 THERMOSTAT 1
26 8 9 574 SPRING HANDLE (DAMPER ROD, SHAKER) 2
27 8 9849 HOOK SPRING HANDLE (FEED, ASH DOOR) 2
28 6908 2 JUNCTION BOX ASSY. 1
2 9 6 9 0 6 9 SHAKER GRATE HANDLE 1

FOR MODEL(S): 24AG, 24AZ

3 0 40369 SHAKER GRATE FRAME 2
3 1 40349 SHAKER GRATE 2
32 40366 FIREBOX LINER 2
3 3 24496 FRONT HEAT PLATE 1
3 4 24487 FURNACE HEAT PLATE 1
35 89066 FIREBRICK 10
3 6 25014G CABINET TOP 1
* * 25 015 CABINET TOP (STAINLESS STEEL) 1
3 7 25016G CABINET RIGHT SIDE 1
* * 25017 CABINET RIGHT SIDE (STAINLESS STEEL) 1
3 8 25018G CABINET LEFT SIDE 1
* * 25019 CABINET LEFT SIDE (STAINLESS STEEL) 1
39 25025B SIDE FILLER 2
4 0 25020G BOTTOM FRONT 1
* * 25021 BOTTOM FRONT (STAINLESS STEEL) 1
41 891049 CATCH 2

N/S 891048 BALL STRIKE 2

4 2 25022G CABINET DOOR 1

* * 25 023 CABINET DOOR (STAINLESS STEEL) 1
N/S 69318B TOP CABINET DOOR HINGE 1
N/S 69319B TOP CABINET DOOR HINGE 1
N/S 851405 ASHLEY SCRIPT LOGO 1

43 25024B LINER, CABINET DOOR 1

4 4 89943 DOOR KNOB 1

45 C60456 1050 CFM DISTRIBUTION BLOWER 1

N/S = NOT SHOWN ** = USED ON 24AZ

USSC Page 9