HearthStone TUCSON User manual

OWNER’S MANUAL
TUCSON Gas-Fired Catalytic Vent-Free Room Heater (8740)
Manufacturedby:
HearthStoneQuality Home Heating Products, Inc.
317 Stafford Avenue
Morrisville, Vermont 05661
READ THIS OWNER’S MANUAL
Operate and maintain this gas heater according to
instructions in this manual.
Read this manual in its entirety.
WARNING
If the information in this manual is not followed exactly, a fire or explosion may result, causing
property damage, personal injury or loss of life.
Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other
appliance.
Installation and service must be performed by a qualified installer, service agency or the gas supplier.
This is an unvented gas-fired heater. It uses air (oxygen) from the room in which it is installed.
Provisions for adequate combustion and ventilation air must be provided. Refer to page 6 of this
manual.
FOR YOUR SAFETY - WHAT TO DO IF YOU SMELL GAS
* DO NOT ATTEMPT TO LIGHT THIS GAS HEATER OR ANY APPLIANCE
* EXTINGUISH ANY OPEN FLAME
* DO NOT TOUCH ANY ELECTRICAL SWITCH
* DO NOT PLUG IN OR UNPLUG ANY APPLIANCE
* DO NOT USE ANY PHONE IN YOUR BUILDING
* OPEN WINDOWS IN THE ROOM AND VACATE THE BUILDING
* TURN OFF THE MAIN GAS SUPPLY
* IMMEDIATELY CALL YOUR GAS SUPPLIER FROM A NEIGHBOR’S PHONE
* FOLLOW THE GAS SUPPLIERS INSTRUCTIONS
* IF YOU CANNOT REACH YOUR GAS SUPPLIER, CALL THE FIRE DEPARTMENT
6400-40434 12/01

OWNER’S MANUAL MODEL: 8740 TUCSON Vent-Free ROOM HEATER
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INFORMATION SHEET
Record, on this page, all relevant information concerning the purchase, installation, and maintenance of
your Tucson gas-fired heater. This information will facilitate servicing, purchase of replacement parts, and
warranty claims (if necessary). Keep your original receipt in a safe place as proof of purchase.
Serial Number:
Fuel type (check one) Natural Gas
Liquid Propane
Sold by:
Phone: Date of Purchase:
Installed by:
Phone: Date of Installation:
Gas Supplier:
Phone:
Read this Owner’s Manual before installing or operating the Tucson gas-fired heater. Retain this manual for
future reference.
SERVICE RECORD
Date Who Performed Work Work Performed Notes
WHAT WHEN WHAT WHEN
Firebox Cleaning............. annually Door Gasket.................... replacement as needed
Catalytic combustor......... visual check annually Glass Cleaning................ as needed
Catalytic combustor......... replacement every 5 yrs. or as needed (do not clean the catalytic combustor)

OWNER’S MANUAL MODEL: 8740 TUCSON Vent-Free ROOM HEATER
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INTRODUCTION
Welcome
Congratulations on the purchase of your HearthStone
Tucson Gas-Fired Catalytic Vent-Free Stove. The
Tucson incorporates the latest in energy and gas
technology which will provide you with clean, efficient
heat for years to come. The combination of natural stone
and cast iron gives the Tucson years of attractive looks
and allows for durable performance which can be
maintained with minimal care.
If there are any questions regarding installation or
operation, which are not answered within this manual,
contact your local dealer or your building inspector.
Your Tucson is equipped with a standing pilot which:
1) generates a millivolt signal that powers the
wall-mounted thermostat and;
2) lights the main burner when the thermostat
calls for heat. (The Tucson requires no
electrical power source for normal operation).
This unit is equipped with a variable output control
located on the gas control valve. It allows you to vary
the heat output, along with the flame height, to suit
personal needs. Heat output can be reduced during the
Fall and Spring (when the need for heat is reduced) and
increased during Winter months (when the need for heat
is the greatest). Regardless of how you set the variable
output control, the on/off cycling of the unit may be
controlled by the wall-mounted thermostat, or the
on/off/Tstat switch.
The Tucson will provide you with years of practical and
convenient service. However, as with any gas appliance,
the unit must be properly installed and maintained by
qualified service personnel to ensure safe and trouble-
free operation.
Table of Contents
Information Sheet...........................................1
Service Record...............................................1
Introduction....................................................2
Safety Information..........................................3
Clearances To Combustibles..........................5
Hearth Requirements/Floor Protection...........5
FreshAirRequirements.....................5
DeterminingSpace Classifications..................6
Meeting FreshAir Requirements....................9
PackingList&Items Required For
Installation......................................................9
Unpack &Inspect For Damage.......................9
Electrical Connections...................................10
Gas Supply &Connections............................11
LogSet Information.......................................12
Before The Stove Is Lit................................13
How To Turn The Unit On & Off................14
Burner Flame Appearance............................15
Initial Adjustments.......................................16
Daily Operation............................................16
Routine Maintenance and Care.....................17
Parts List.........................................19
Specifications...............................................19
Trouble Shooting.........................................20
Warranty......................................................22
READ THIS OWNER’S MANUAL
Operate and maintain this gas heater according to
instructions in this manual. Read this manual in its
entirety.

OWNER’S MANUAL MODEL: 8740 TUCSON Vent-Free ROOM HEATER
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SAFETY INFORMATION
Your Tucson Vent-Free is very attractive and extremely efficient,
utilizing today’s best technologies. By following a few simple
safety precautions and by performing minimal maintenance, the
unit will remain appealing while providing years of quality
performance.
WARNING
Installation and repair should be done by a qualified service
person. The appliance should be inspected before use and at
least annually by a qualified service person. It is imperative
that control compartments, burners, and circulating air
passages of the appliance are kept clean and free of
obstructions.
IMPORTANT
Please read and understand all warnings before installing or
operating this heater. Failure to follow these instructions or
improper use of this heater will void the warranty and can
cause serious injury or death from burns, fire, explosion and
carbon monoxide poisoning. Do not attempt to alter or modify
the construction of this heater or its components. Any
alteration or modification of construction voids the warranty
and the certification of this heater. Save this manual for future
reference.
DANGER: CARBON MONOXIDE
POISONING MAY LEAD TO DEATH!
Carbon Monoxide Poisoning: Early signs of carbon monoxide
poisoning resemble the flu with headaches, dizziness, and/or
nausea. If you have these signs, get fresh air immediately! Have
the heater serviced, as it may not be operating properly. As a safety
precaution, a CO monitor may be installed in or near the room
where the unit will be operating.
The installation must conform with local codes or, in the absences
of local codes, the current National Fuel Gas Code, ANSI Z223.1
(NFPA 54).
DO NOT INSTALL THIS HEATER IN A BEDROOM OR
BATHROOM.
Do not use this heater if any part has been under water.
Immediately call a qualified service technician to inspect the heater
and to replace any part of the control system and gas control which
has been under water.
This heater has a standing pilot which incorporates an Oxygen
Depletion System (ODS). The ODS shuts off the flow of gas to the
pilot and the burner in the event that sufficient fresh air becomes
unavailable for continued safe operation of the heater. If this heater
shuts off during operation, sufficient fresh air may not be available.
Refer to the Troubleshooting or Fresh Air Requirements sections
of this manual, or call a qualified service technician.
Avoid any drafts that alter the burner flame patterns. Do not
allow fans to blow directly into the heater. Ceiling fans may
create drafts that alter burner flame patterns. Sooting and
improper burning may occur.
This unvented gas heater is intended to be smokeless. During the
first few hours of operation the appliance may produce a slight
smoke and/or odor. This is normal during the first burn. During
the initial burn, open a window(s) to assist in the removal of the
smoke/odor. If the logs appear to smoke, turn the heater off and
call a qualified service technician.
During any pressure testing of supply piping system in excess of
½ psi (14" w.c.), the heater and its control valve must be
disconnected from the gas supply system.
If equal to or less
than ½ psig, it must be isolated from the gas supply piping
system by closing its individual manual shutoff valve.

OWNER’S MANUAL MODEL: 8740 TUCSON Vent-Free ROOM HEATER
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SAFETY INFORMATION cont.
WARNING: DO NOT OPERATE THIS HEATER
WITHOUT THE CATALYTIC COMBUSTOR PROPERLY
INSTALLED. IF THE CATALYST APPEARS ALTERED
OR DAMAGED, DO NOT USE THE APPLIANCE UNTIL
THE CATALYST IS REPLACED.
HOT SURFACES
Certain exposed surfaces of the Tucson will reach high
temperatures during normal operation. Clearances to
combustibles must be maintained, as specified in the Clearances
To Combustibles section of this manual. The Tucson should be
located out of traffic and away from furniture, draperies, clothing
and flammable materials. Do not place objects that may obstruct
air circulation on, under, or near the heater. Do not place objects
on the top grill of the stove. Doing so will obstruct the air flow
of the stove, preventing it from operating properly. Clean the
area around, under, and behind the unit on a regular basis to
prevent the accumulation of dust and lint.
Children and adults who are unfamiliar with heaters of this type
should be alerted to the hazards of high surface temperatures and
warned that they should stay away to avoid burns to skin and
clothing. Children should be carefully supervised when in the
same area as the Tucson heater. Do not leave children unattended
in the vicinity of this unit.
NEVER BURN PAPER, WOOD, OR OTHER
MATERIALS
This gas heater is designed to burn either natural gas(NG) or
liquid propane(LP). Never burn any fuel which was not intended
for use.
DO NOT LIGHT PILOT OR MAIN BURNERS BY
HAND
The standing pilot light equipped with this gas heater is lit by
using a piezoelectric spark generator, as described in the How To
Turn the Unit On & Off section of this manual. Never attempt to
light the pilot or main burners by hand (with a match or lighter).
After repeated attempts, if the pilot light fails to light,
discontinue operation, turn off the gas at the gas control valve,
and immediately contact qualified service personnel for
assistance.
FIRE HAZARD
Do not store or use gasoline or other flammable vapors and
liquids in the vicinity of this appliance. The Tucson should be
located out of traffic and away from furniture, draperies,
clothing, and flammable material.
CERAMIC FIBER LOG SAFETY INFORMATION
If the decorative ceramic logs and ember strip material
supplied with the Tucson are damaged or missing, they
must be replaced with the same, approved replacement
parts supplied by the manufacturer. These components
affect the combustion quality and safety of the heater. Do
not replace fiber ceramic logs or ember strip with
unapproved ceramic logs or any other material. Always
wear gloves and safety goggles while handling the log
set and ember strip.
SERVICE CAUTION
If you believe your Tucson is not, in any way, performing
properly, immediately discontinue operation until the unit
has been inspected and approved by qualified service
personnel. Prior to servicing the unit, turn the valve control
knob clockwise to “OFF”. The unit should be cool prior to
servicing and cleaning. Any component removed during
servicing should be replaced prior to operation. Use of any
components not supplied by HearthStone. on the stove
voids all warranties. Do not substitute components.

OWNER’S MANUAL MODEL: 8740 TUCSON Vent-Free ROOM HEATER
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CLEARANCES TO COMBUSTIBLES
Due to high surface temperatures,
the Tucson should be located out of
traffic and away from furniture and
draperies. Clothing and other
flammable material should not be
placed on or near the Tucson heater.
Always maintain adequate
clearances around the air openings
into the combustion chamber and
allow for adequate ventilation.
Minimum clearances to
combustibles must be maintained as
shown to the right, in Figures 1-4.
HEARTH
REQUIREMENTS/FLOO
R PROTECTION
The Tucson can be installed on wood
flooring or a non-combustible surface.
For installation of the Tucson on
carpeting, vinyl tile, or other combustible materials
other than wood flooring, the unit shall be installed on
a metal, wood, or other non-combustible hearth.
The required size of the hearth is thesame
as the outline of the stove (shown in Figure 19).
NOTE: Some wood floor varnishes, stains, or
polyurethane may be affected by heat.
CODES
Adhere to all local codes or, in their absence, the latest edition of THE NATIONAL FUEL GAS CODE ANSI Z223.1
(NFPA54) which can be obtained from:
AMERICAN NATIONAL STANDARDS INSTITUTE, INC.
1430 BROADWAY
NEW YORK, NY 10018
OR
NATIONAL FIRE PROTECTION ASSOCIATION, INC.
BATTERY MARCH PARK
QUINCY, MA 02269
FRESH AIR REQUIREMENTS
Your Tucson stove requires an adequate supply of fresh air
to function properly and safely. The fresh air supply must be
met within the space in which the heater is to be installed. To
ensure an adequate supply of fresh air is available for proper
and safe operation of your Tucson stove, the following
information must be considered when installing the appliance
in a mobile home, modular home, or an on-site house, Refer
to Figure 5.
The space in which the heater should be installed will fall

OWNER’S MANUAL MODEL: 8740 TUCSON Vent-Free ROOM HEATER
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into one of the following categories: 1. Unusually tight construction
2. Unconfined space
3. Confined space
WARNING: If the area in which the heater may be
operated is smaller than that defined as an unconfined
space, provide adequate combustion and ventilation air
by one of the methods described in the National Fuel Gas
Code ANSI Z223.1, Latest Edition, Section 5.3.
DETERMINING SPACE CLASSIFICATION
Unusually tight construction
This is construction where:
a. Walls and ceilings exposed to the outside atmosphere have
a continuous water vapor retarder with a rating of one perm
(6 x 10
G ¹¹ kg per pa-sec-m²) or less with openings gasketed
or sealed, and
b. Weatherstripping has been added on openable windows
and doors, and
c. Caulking or sealants are applied to areas such as joints
around window and door frames, between sole plates and
floors, between wall ceiling joints, between wall panels, at
penetrations for plumbing, electrical, and gas lines, and at
other openings.
If the space in which the heater will be installed falls into this
category, supplemental fresh air must be provided, as
outlined in the Meeting Fresh Air Requirements section of
this manual.
Unconfined space
If the space in which the heater is to be installed meets the
following criteria, it is considered to be an unconfined space.
The room in which the heater is to be installed has an air
volume of at least 50 cubic feet (cubic feet = length x width
x height of the space) for each 1000 BTU/hr (4.8 m³ / K. W.)
input rating for all appliances in the space. This includes
adjoining rooms only if there are doorless passageways
between them, or there are vents between the rooms. If the
space in which the unit is being installed is an unconfined
space, additional fresh air is not needed.
Confined space
If the space in which the heater is to be installed meets the
following criteria, it is considered a confined space.
The room in which the heater is to be installed has an air
volume of less than 50 cubic feet for each 1000 BTU/hr (4.8
m³ / K. W.) input rating for all appliances in the space. This
includes adjoining rooms only if there are doorless
passageways between them, or there are vents between the
rooms.(See Figure 5).
If the space in which the heater is to be installed is a confined
space, additional fresh air must be provided. This can be
done by one of the ways outlined in the Meeting Fresh Air
Requirements section of this manual.
Example (refer to Figure 5)
I. Determine the volume of the space where the unit will be
installed. Volume = length x width x height. Also included
in the volume of the space is the volume of any adjoining
rooms, only if there are doorless passage ways between them,
or if there are vents between the rooms.
II. Multiply the volume by 1000 BTU/hr, then divide that
number by 50 cubic feet, to obtain the

OWNER’S MANUAL MODEL: 8740 TUCSON Vent-Free ROOM HEATER
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The following formula can be used to determine the maximum heater rating per the
definition of unconfined space:
(L1 + L2) FT x (W) FT x (H) FT x 1000
BTU/HR =
50
EXAMPLE:
Consider two connecting rooms with an open area between, with the following dimensions:
L1 = 15 1/2 Ft., L2 = 12 Ft., W = 12Ft., H = 8 Ft.
(15 1/2 + 12) x (12) x (8) x 1000
BTU/HR =
50
BTU/HR = 52,800
If there were a door between the two rooms the calculation would be based only on the
room with the heater.
(15 1/2) x (12) x (8) x 1000
BTU/HR =
50
BTU/HR = 29,760
DETERMINING SPACE CLASSIFICATION cont.
total maximum BTU/hr rating which the room can support.
III. Add the BTU/hr ratings of all fuel burning appliances
installed within the same space. The BTU rating for this unit
is 20,000 BTU/hr. (Do not include any direct vent
appliances, as these types of appliances use outside air for
combustion and venting).
IV. Compare the maximum BTU/hr rating that the room can
support (from II.) with the maximum BTU/hr rating of the
combined appliances (from III.). If the number from III. is
smaller than the number calculated in II., the space should be
considered an unconfined space. If the number from III. is
larger than II., the space should be considered a confined
space, and additional fresh air must be provided. This can be
done by one of several ways.

OWNER’S MANUAL MODEL: 8740 TUCSON Vent-Free ROOM HEATER
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INLET AIR
OPENINGS
VENTILATION LOUVERS
(EACH END OF ATTIC)
VENTILATION LOUVERS FOR
UNHEATED CRAWL SPACE
FIGURE 6
FIGURE 7
FIGURE 8
(EACH END OF ATTIC)
VENTILATION LOUVERS
OUTLET
AIR
INLET AIR DUCT
(ENDS 1 FT ABOVE FLOOR)
FIGURE 9
OUTLET AIR
DUCT
INLET AIR
DUCT
OUTLET
AIR
MEETING FRESH AIR REQUIREMENTS
1. Air from inside the building.The confined space shall be
provided with two permanent openings communicating directly
with an additional room(s), of sufficient volume, so that the
combined volume of all spaces meets the criteria for an
unconfined space. The total input of all gas utilization equipment
installed in the combined space shall be considered in making this
determination. Each opening shall have a minimum free area of 1
square inch per 1,000 BTU/hr (22 cm² / kW) of the total input
rating of all gas utilization equipment in the confined space, but
not less than 100 square inches (645 cm²). One opening shall
commence within 12 inches (30 cm) of the top, and one opening
shall commence within 12 inches (30 cm) of the bottom, of the
enclosure. The minimum dimension of air openings shall not be
less than 9 square inches (8 cm) (see Figure 6).
2. All air from outdoors. The confined space needs to have two
permanent openings, one commencing within 12 inches (30 cm)
of the top, and one commencing within 12 inches (30 cm) of the
bottom, of the enclosure. The openings shall communicate freely
with the outdoors, either directly, by ducts, or by spaces (crawl or
attic). The minimum dimension of air openings shall be not less
than 9 square inches (8 cm). See Figures 7 thru 9.
A. Where directly communicating with the outdoors, each
opening shall have a minimum free area of 1 square inch per
4,000 BTU/hr (5.5 cm² / kW) of total input rating of all equipment
in the enclosure. See Figure 7.
B. Where communicating with the outdoors through vertical
ducts, each opening shall have a minimum free area of 1 square
inch per 4,000 BTU/hr (5.5 cm² / kW) of total input rating of all
equipment in the enclosure (See Figure 8).
C. Where communicating with the outdoors through horizontal
ducts, each opening shall have a minimum free area of 1 square
inch per 2,000 BTU/hr (11 cm² / kW) of total input rating of all
equipment in the enclosure (See Figure 9).
D. Where ducts are used, they shall be of the same cross-
sectional area as the free area of the openings to which they
connect.

OWNER’S MANUAL MODEL: 8740 TUCSON Vent-Free ROOM HEATER
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PACKING LIST & ITEMS REQUIRED FOR INSTALLATION
Packing list
1 - Tucson Vent-Free
Gas-Fired Heater
1 - Decorative Ceramic Fiber Log
1 - Ember Strip
1 - Thermostat with 40' wire
1 - Owners Manual
1 - Warranty Validation Form
Items Required For Installation
Ensure that the following items are available before proceeding with
installation:
1/8 Allen wrench
An external regulator (for propane/ L. P. gas only)
Gas piping which complies with local codes
Pipe sealants approved for use with propane/L. P. Gas (resistant to
sulfur compounds)
A manual shutoff valve for the gas supply
A sediment trap
Pipe wrenches
Phillips head screwdriver
Other parts required by local code
Safety glasses
Gloves
UNPACK & INSPECT FOR DAMAGE
Unpack
The Tucson is packaged by the manufacturer to
withstand shipment without damage under most
circumstances. However, damage can occur during
transit and handling. Care should be taken when
unpacking, inspecting for damage, and installing the
unit. If any damaged or missing parts are detected,
immediately contact your dealer.
After removing the shipping carton, carefully remove the
top three stones and grill. Use the protective wrapping
material to temporarily protect the stones from chipping
or damage while the unit is inspected and installed.
With the top stones and grill removed and set aside, undo
the lag bolts that fasten the unit to the pallet. Take care
not to mar or chip the legs if enameled. Lift the stove off
the pallet and set it in place, (with regards to the
Clearances To Combustibles section of this manual.)
Inspect for damage
Inspect the Tucson for visible and/or concealed damage.
The unit should appear to be square and true. The stones
should be whole and without cracks, chips, or breakage.
The sheet metal parts should be smooth and free of
bends and/or dents.
If the heater is enameled, the enameled cast iron should
be free of chips and/or cracks. If visible or concealed
damage is found or suspected, contact your local dealer
for instructions.
The Owner’s Manual, thermostat (with wire), removable
ash lip, and the decorative ceramic fiber logs, supplied with
the Tucson, are contained within the firebox. It is
important to wear the safety goggles and gloves when
handling the log set. Open the firebox door using a 1/8
allen wrench and inspect the logs for damage. If a damaged
log is encountered, contact your local dealer for
replacement logs. Put the logset, thermostat, and the ash lip
aside. They will be installed later.

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Violet
Black
Yellow
On/Off/T-stat
ELECTRICAL CONNECTIONS
NOTE: OPEN VALVE DOOR UNDER ASH LIP FOR
ELECTRICAL AND GAS CONNECTIONS
Thermostat
The Tucson may use the wall mounted thermostat for
operation, or the on/off/tstat switch. The thermostat controls
the unit by “calling for heat.” The thermostat turns the unit
on when the room is cold, and turns the unit off once the
room is warmed sufficiently. The thermostat is controlled by
a 750 millivolt DC two-wire circuit. Both the thermostat and
40' (12m) of thermostat wire are included as standard
equipment.
Thermostat Placement
The thermostat should be placed in the same room or living
space as the unit. Typically 5' (1.5 m) off the floor and away
from any influences that may cause the temperature in the
vicinity of the thermostat to be unrepresentative of the room
temperature in general. Such influences might include strong
lighting, a heater vent from the central heating system, or a
nearby drafty window.
Placement of the thermostat on an inside wall rather than an
outside wall is preferable. Do not place the thermostat
directly behind or too close to the unit, otherwise heat from
the unit will immediately satisfy the thermostat and turn the
unit off.
Thermostat Wiring
The thermostat wire from the unit to the thermostat can be
surface mounted, routed under the floor, or through walls,
etc. The thermostat should be connected to the unit using the
40' (12 m), or as much as needed, of insulated thermostat
wire provided. Be sure to leave a small coil of wire behind
the unit so that it can be moved out of position for servicing
and cleaning.
The proper location of wire connections is shown below and
in Figure 10. When making these connections, position the
thermostat wire so it extends towards the wall behind the
unit, then towards the thermostat. (At the thermostat, the
wires should be connected to the two connection screws on
the back of the thermostat per the instructions received with
the thermostat). Take care not to over-tighten the connection
screws and not to damage the internal parts of the thermostat.
Now attach the wires in their proper location, shown in
Figure 10.
Location of Wire Connections:
WIRE LOCATION LABEL
Thermostat(2 wires) 1- Top Post on Valve TH
1- On/Off/T-stat switch Yellow wire
Thermopile(2 wires) 1- Bottom Post TP/TH
1- Middle Post TP

OWNER’S MANUAL MODEL: 8740 TUCSON Vent-Free ROOM HEATER
-11-
Figure 11
GAS SUPPLY & CONNECTIONS
Gas Supply
NOTICE: A qualified technician must connect the
heater to the gas supply and leak test the unit before
it is approved for use. Consult all local codes.
WARNING: The unit must be installed and connected
in accordance with local codes, or in the absence of
local codes, with the most current edition of the
National Fuel Gas Code ANSI Z223.1/NFPA 54.
We recommend using new black iron or steel pipe
only. Internally tinned copper tubing can be used in
some areas when permitted by local codes. Only use
pipe of ½" or greater diameter to allow full gas volume
to heater. Excessive pressure loss will occur if the pipe
is too small.
The supply line must include a manual shut-off valve
and union so that the unit can be disconnected for
servicing Also a sediment trap must be installed
upstream of the heater. The sediment trap is installed to
prevent moisture and contaminants from passing
through the pipe to the heater controls and burners.
Failure to install a sediment trap could prevent the
heater from operating reliably.
The gas supply line connection is made to the Tucson’s
gas control valve just inside the left front leg of the unit
using a
d" male NPT fitting. The supply line should
be ½" diameter or appropriately sized to provide a
sufficient gas supply to meet the maximum demand of
the unit without undue loss of pressure. We
recommend a flexible line to avoid undue mechanical
load on the valve and to ease thread alignment, but also
refer to local code.
CAUTION: Check Gas Type! The gas supply must
be the same as stated on the heater’s rating
plate(located on the back of the unit). If the gas supply
is different, DO NOT INSTALL the heater. Contact
your dealer for the correct model.
Gas Pressure Adjustment
The supply line pressure is tested, to ensure it meets
the minimum pressure, as listed in the Specifications
sections of this manual, for the type of fuel in use (NG
or LP). The Tucson must be isolated from the gas
supply piping system by closing its individual manual
shutoff valve during any pressure testing of the gas
supply piping system at test pressures equal to or less
than ½" psig. During tests in excess of ½" psig. (14"
w.c.), the heater must be disconnected from the gas
supply system. Test by connecting a manometer to the
supply line. Adjust the incoming pressure, if
necessary, to meet the required supply line pressure.
Once connected to the gas supply, the gas inlet
pressure and manifold gas pressure must be tested. The
gas inlet tap (6) and manifold pressure tap (7) is
located on the control valve (see Figure 11). Connect
a manometer to the test points on the gas control valve,
refer to #’s 6 & 7 of Figure 11 for locations.

OWNER’S MANUAL MODEL: 8740 TUCSON Vent-Free ROOM HEATER
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Figure 13
Figure 12
LOG SET INFORMATION
CAUTION: Fragile! Handle log set and ember
strip with care. Always wear gloves and safety
goggles while handling the log set and the ember
strip.
Log Placement Within The Unit
Only the decorative ceramic fiber log set supplied with
the unit should be placed in the firebox. Do not place
other ceramic logs, real wood logs or other material in
the firebox. If the log set is damaged or broken contact
your dealer for replacement.
If the log set does not set into the firebox exactly as
outlined below, contact your dealer for assistance.
Exact positioning of the log set is required in order to
obtain a pleasing flame pattern and efficient
combustion. Incorrect log placement may cause carbon
build-up, excess thermal stress on the log set and stove
parts, reduced efficiency, and high levels of carbon
monoxide.
The decorative ceramic fiber log set will give long
service when in use; however, they will break if
subjected to rough or improper handling. Broken or
cracked logs should be replaced. When removing and
replacing the log set from the unit during routine
cleaning or service of the unit, take care not to damage
the logs and to position the log set per instructions
above. Also, take care not to chip the enamel on the
door and door frame when removing and replacing the
log set.
Installation of Log Set
Refer to figures 12 & 13 for log set assembly
.
1) Open the front door using a 1/8" allen wrench.
Loosen the bolt that fastens the door frame to the
firebox by turning it counterclockwise. Be careful not
to chip enamel when loosening the bolt. Pull the door
open by grabbing the top edge of the door frame.
2) Remove the packaging material around the log set
assembly. Be careful not to damage the log set when
unpacking.
LOG SET INFORMATION cont.

OWNER’S MANUAL MODEL: 8740 TUCSON Vent-Free ROOM HEATER
-13-
3) Gently place the Rear Log (1) in the firebox against
the center of the back wall.
4) Gently place the Middle Log (2) in the fire box
against the front of the Rear Log. There are slots on
the underside that fit in between the burner tube and
into the burner tube holder. The rear tabs on the
Middle Log should touch the front of the Rear Log, and
the log should be centered as best as possible.
5) Place the Ember Screen (3) on the front burner tube
with the long side of the Screen to the front, and the
tabs should be facing down.
6) Gently place the Front Log (4) in the firebox against
the front of the burner tube. Center as best as possible.
7) Spread evenly across the Ember Screen, the 2
ounces of Charcoal Embers (5).
8) Gently place the Top Log (6) in the firebox on top of
the Middle Log. The Middle log has 2 posts which
slide into the 2 holes on the underside of the Top Log.
The “leg” on the Top Log points towards the front.
9) With the 1/8" allen wrench fasten the door to the
firebox. Make sure the door is properly secured to the
firebox before turning the unit on. Be careful not to
chip the enamel when fastening the door.
Removal of Log Set
CAUTION: Log set and charcoal embers retain heat
and can be very hot! Allow 2 to 3 hours after pilot
light is turned off before handling.
CAUTION: Fragile! Handle log set and charcoal
embers with care.
Open door using the 1/8 allen wrench. Loosen the
screw that secures the door to the firebox by turning
it counterclockwise. Pull the door open by grabbing
the top edge of door frame. Take care not to chip the
enamel or to damage the log set when removing the
log set from the firebox. The log set assembly will be
in four pieces along with the charcoal embers as
shown in Figure 13. First, remove the Top Log(6) by
pulling it up off the Middle Log(2) and out of the
firebox. Next remove the charcoal embers. Then lift
upwards and pull the Front Log(4) out of the firebox.
Next remove the ember screen(3) from the burner
tube. Grip the Middle Log(2) and lift upward, off the
burner tube holder, and out of the firebox. The Rear
Log(1) can then be removed from the firebox. Place
the logs and charcoal embers in a safe area where
they will not be damaged.
BEFORE THE STOVE IS LIT
CAUTION: Lighting the Tucson for the first time
and adjustments to the unit should be performed
by qualified service personnel.
WARNING: If you do not follow these instructions
exactly, a fire or explosion may result causing
property damage, personal injury or loss of life.
Initial Adjustments
Once the Tucson has been set in place and connected
as described in the Gas Supply & Connections and
Electrical Connections sections of this manual, the
unit is ready to be lit for the first time. Each unit is
tested prior to shipment by the manufacturer, so
ignition should take place without failure. However,
a number of small adjustments may be necessary to
compensate for variations in gas pressure, altitude,
and other factors particular to each installation.
Smoke and Fumes Warning
When lit for the first time, the unit will emit some
smoke and fumes. This is normal “off-gassing” of
the paints and oils used in the manufacturing and
assembly of the unit. Open windows to vent the room
if necessary. The off-gassing and fumes will subside
after the first 10 to 20 minutes of operation.

OWNER’S MANUAL MODEL: 8740 TUCSON Vent-Free ROOM HEATER
-14-
BEFORE THE STOVE IS LIT cont.
Odors and Impurities
A Vent-Free combustion system is such that odors
may be produced during heater operation due to
impurities that may exist in the immediate area.
Sources of impurities can be cleaning solvents, paint
solvents, cigarettes, smoke, pet hair, dust, adhesives,
new carpet, and/or textiles. If any fumes of this sort
mix with the combustion fumes, an odor may
develop. Such odors will dissipate. However, the
condition can be alleviated by opening a window or
otherwise providing additional ventilation to the area.
If any odor persists, contact your dealer or an
authorized service technician.
WARNING: THE CONTROL HAS AN
INTERLOCK DEVICE. AFTER SHUTTING OFF
ALL GAS FLOW, THE PILOT BURNER CANNOT
BE RELIT UNTIL THE THERMOCOUPLE HAS
COOLED, ALLOWING THE ELECTROMAGNET
TO BE RELEASED (APPROX. 60 SEC). THE GAS
CONTROL KNOB IS DESIGNED TO BE
OPERATED BY HAND. NEVER USE ANY
TOOLS DURING THIS OPERATION. IF THE
KNOB WILL NOT PUSH IN OR TURN BY HAND,
DON’T TRY TO REPAIR IT, CALL A QUALIFIED
SERVICE TECHNICIAN. DAMAGED KNOBS
MAY RESULT IN FIRE, EXPLOSION, OR
SERIOUS INJURY.
Pilot Light Warning
The Tucson has a piezoelectric spark ignitor (the
push button located next to the gas control valve
behind the valve access door) which ignites the pilot
light by means of a spark at the pilot light assembly.
Do not attempt to light the unit with a match or by
any means other than the piezoelectric spark ignitor.
Prepare for Lighting
Prepare for the lighting procedure by adjusting the
thermostat to its lowest setting or OFF position. If the
gas control knob is not in the OFF position, turn the
knob fully clockwise to OFF. Locate the variable
output and turn it fully clockwise to the highest
setting.
Prior to lighting the unit for the first time, wait 5
minutes to allow any residual gas within the unit to
dissipate. Smell all around the appliance area for gas.
Be sure to smell next to the floor because some gases
are heavier than air and will settle on the floor. If you
do not smell gas after this five minute period, proceed
with the lighting procedure. If you do smell gas, do
not proceed with the lighting procedure. Instead,
immediately refer to the What To Do If You Smell
Gas Warning, on the cover of this manual.
HOW TO TURN THE UNIT ON & OFF
Lighting the Unit
1. STOP! Read the What To Do If You Smell Gas!
warning.
2. Set the on/off/T-stat switch or thermostat to the
off position.
3. Push in and turn the gas control knob clockwise
to “OFF”.
4. Wait (5) five minutes to clear out any gas. If you
then smell gas, STOP!, immediately follow the
What To Do If You Smell Gas! warning (on the
cover of this manual). Smell all around the
appliance area for gas. Be sure to smell next to
the floor because some gases are heavier than air
and will settle on the floor. If you do not smell
gas, proceed to the next step.
5. Turn the gas control knob counterclockwise to
“PILOT”.
6. Push in the control knob all the way and hold it in.
Immediately light the pilot with the gas lighter
(push in and “click” the piezoelectric spark
ignitor button several times until lit). Continue to
hold the control knob in for about 20 seconds after
the pilot is lit. Release the knob and it will pop
back out. The pilot should remain lit. If the pilot
goes out, repeat the operation.

OWNER’S MANUAL MODEL: 8740 TUCSON Vent-Free ROOM HEATER
-15-
Figure 14
HOW TO TURN THE UNIT ON & OFF cont.
* If the knob does not pop out when released, stop
and immediately call a qualified service
technician or gas supplier.
* If the pilot will not stay lit after several tries,
turn the gas control knob clockwise to “OFF”
and call a qualified service technician or gas
supplier.
7. After the pilot lights, turn the gas control knob
counterclockwise to “ON”.
8. Select the “ON” or “T-STAT” position of the
On/Off/T-stat switch. Shut the gas control
valve access door.
9. If the “T-STAT” position was selected, set
thermostat to “ON” and set the desired
temperature setting.
NOTE: When pressing/clicking the piezoelectric
spark ignition button to light the pilot, watch
through the glass (front door) of the unit. Click
the ignitor button until a flame is visible at the
pilot. Once the pilot is lit, continue to press on the
gas control knob for another 20 seconds, then
release. Ascertain that the pilot is still lit by
looking through the front door. If lit, then turn the
gas control knob fully counterclockwise to the
“ON” position. If the pilot fails to light or if it
went out due to a premature release of the gas
control knob while pressed in the “PILOT”
position, wait 60 seconds for the Interlock to
release. Then repeat the lighting process as
described in the Lighting the Unit portion of this
section of the manual.
Once the pilot has been lit, and the gas control
knob has been turned to the “ON” position, the
main burners are lit by selecting “ON” of the
On/Off/T-stat switch, or if “T-STAT” was selected,
by moving the thermostat to a high setting so that
it “calls” for heat (i.e. turns the unit on). The main
burners should light immediately. Note that the
on/off cycling of the main burners is controlled by
the thermostat, but the pilot remains lit regardless
of the thermostat setting. To turn the pilot off,
turn the gas control valve fully clockwise to the
“Off” position.
Turning Off the Unit
1. Set thermostat to the “Off” position.
2. If shutting the unit off for the non-heating
season, turn the gas control knob fully
clockwise to the “Off” position. Do not force
the knob to turn.
BURNER FLAME APPEARANCE
Burner Flame Appearance
Once the unit is lit, observe the flame pattern and
adjust as necessary. Also a periodic visual check of
the burner flame should be performed. To determine
if the burner flame needs adjustment, it is necessary
to view the flame pattern with the variable output
control knob at its highest setting(turned fully
clockwise). Allow the unit to operate for 10 minutes
enabling the entire unit to reach temperature and for
the flame pattern to stabilize. The flame pattern
should be similar to the one shown in Figure 14.
There are several guidelines to aid in determining if
the flame pattern is correct:
11) the flame should not be dirty or lick the top of the
stove
2) the flame should not raise off of the burner tube,
called “lifting”
3) flames should not impinge heavily on log set, they
should “fit” through the pre-formed spaces
designed in the log set

OWNER’S MANUAL MODEL: 8740 TUCSON Vent-Free ROOM HEATER
-16-
INITIAL ADJUSTMENTS
Variable Output Control
The gas control valve is equipped with a variable
output control. This control varies the rate of heat
produced by the unit by varying the gas pressure to
the main burner tube. The length of the burn cycle is
affected by a combination of heat output and the
thermostat setting. If your stove cycles on and off
often, try, first, reducing the burn cycle by turning the
HI/LOW knob, on the control valve to a lower setting.
Using the variable output control, the heat output of
the unit can be reduced for mild fall and spring
months, or maximized for the colder winter months.
This adjustment can be made by the homeowner as
necessary by turning the variable output control knob
to “HI”, “LO”, or any setting in between.
Air Shutter
The air shutter is preset by the manufacturer for
optimum operation and should not be adjusted by the
owner. The air shutter is used to regulate the air-to-
gas combustion mixture which in turn influences the
size and color of the flames.
Pilot Adjustment
The pilot light is preset by the manufacturer and
should not need adjustment. The pilot light flame
should be large enough to engulf the thermopile and,
on a NG assembly, the thermocouple as well (located
next to the pilot), but not so large as to create
excessive noise or consume excessive gas. However,
it can be adjusted by means of the pilot light
adjustment screw located on the gas control valve.
Open valve door to access the pilot adjustment
screw.
Refer to # 3 of Figure 11 to
determine the location of the pilot adjustment screw.
Note that the pilot flame must engulf the thermopile
so that the thermopile can generate sufficient milli-
voltage (325 to 750mv) to power the millivolt gas
control valve. The flame on the pilot should look like
Figures 15a & 15b. Controlling the Tucson by the
wall mounted thermostat may become erratic,
nonexistent, or the unit may go out, if the pilot light
flame is too small or misdirected away from the
thermopile.
Figure 15a Pilot Flame Pattern (NG GAS)
Figure 15b Pilot Flame Pattern (LP GAS)
DAILY OPERATION
Daily Operation
The Tucson gas-fired heater is easily operated by
the homeowner once installed and adjusted by
qualified service personnel. The unit is controlled
via the wall-mounted thermostat during the heating
season. Set the thermostat to the desired room
temperature and the unit will cycle on and off as
required. By adjusting the variable output control,
located on the gas control valve, the rate of heat
output can be varied to meet the heating
requirements of the season. Choosing a low flame
setting will result in longer burn cycles at a reduced
output, while choosing a high flame setting will
result in a shorter, hotter burn cycle.

OWNER’S MANUAL MODEL: 8740 TUCSON Vent-Free ROOM HEATER
-17-
DAILY OPERATION cont.
Through trial and error the homeowner can select
the optimum flame size for their setting and
application.
During the summer, non-heating season, switch
the wall thermostat to “OFF”, and turn off the
pilot. This will improve the overall efficiency of
the unit as the heat from the pilot is not wanted in
the summer. When putting the unit back into
service follow the Lighting
the Unit portion in the How To Turn the Unit On & Off
section of this manual.
When the unit is first lit, especially when cool, it is
normal to experience some condensation on the inside of
the glass window. This condensation will burn off
within the first few minutes of operation. If continuous
condensation or water drips are noted from any part of
the unit, immediately discontinue operation of the unit
and contact qualified service personnel.
ROUTINE MAINTENANCE AND CARE
Routine Maintenance and Care
The Tucson requires minimal routine maintenance
and care. The unit should always be cool and off
when being cleaned.
WARNING: Do not substitute Materials.
For replacement parts, or for information about parts
or service, contact your local HearthStone dealer.
Catalytic Combustor
The is the ceramic block with small square holes,
located on top of the combustion chamber. Do not
attempt to clean the catalyst. Attempts to clean the
catalyst may be dangerous. The catalytic combustor
does, however, require periodic visual checks.
Inspect for damage, free flow, and buildup of
contaminants. If any of these things are detected,
replace the catalyst immediately. The catalyst should
be replaced every 5 years (minimum).
Cleaning
The unit should receive regular cleaning on, under,
and around the stove to prevent the buildup of dust
and lint. The exterior surfaces of the unit can be
cleaned using soap, water, and a soft cloth. Do not
use abrasive or chemical cleaners and take care not to
scratch the stones, glass, or enamel finish (if so
equipped) when cleaning the unit. The use of
chemical or wax based cleaners or polishes is not
recommended due to the potential for discoloration of
the stones when the residue of the cleaners or
polishes is exposed to heat.
Firebox
The firebox should receive periodic cleaning to
prevent the accumulation of dust, lint, and other
debris. To clean the firebox, set the thermostat to the
“OFF” position, and turn off the gas at the gas control
valve. When the unit is cool, unfasten the front door
and carefully remove the decorative ceramic fiber log
set (after they have cooled), taking care not to
damage the logs or chip the enamel cast iron. Clean
the firebox, burner tube, pilot assembly, and
carefully vacuum the entire surface of the log set.
Take care to thoroughly vacuum the ports (holes)
along the top of the burner tubes and the pilot
assembly.
Pilot & Burner Flames
With the decorative ceramic fiber logs out of the
firebox, fasten the door shut and momentarily light
the unit according to lighting instructions described
in the How To Turn the Unit On & Off section of this
manual. Check to ensure a flame is burning from
each burner port. The pilot flame should be large
enough to engulf the thermocouple as shown in
Figures 15a and 15b. NOTE: Do not operate the unit
for more than 1-2 minutes without the log set in
place. Turn the unit off by setting the thermostat to
“Off”, and turning off the gas control valve. Allow
the unit to cool.

OWNER’S MANUAL MODEL: 8740 TUCSON Vent-Free ROOM HEATER
-18-
ROUTINE MAINTENANCE AND CARE cont.
Check and clean any burner ports which were not
burning properly or at all. Clean burner ports using
a soft brush or vacuum cleaner. If the pilot flame
height needs adjustment it should be adjusted by
qualified service personnel as described in the Initial
Adjustments section of this manual.
Complete the cleaning procedure by carefully placing
the log set within the firebox as described in the Log
Set Information section of this manual. Close and
fasten the front door. Turn on the gas, light the unit
and check for proper operation. Flame patterns
should look like Figure 14. Regularly check to insure
the area around the Tucson is kept free and clear from
combustible materials, gasoline, and other flammable
vapors and liquids. Check that the flow of
combustion and ventilation air is not obstructed.
Once a year the unit should be inspected by
qualified service personnel to ensure that it is
clean, free of obstruction, safe, and in good
working order. If service or maintenance is
required, it should be performed by qualified
service personnel.
Replacing the Door Gasket
Your Tucson uses a 3/8" rope-type fiberglass gasket
to make a tight seal between the door frame and the
firebox. In time, the gasket can become brittle and
compressed and should be replaced. New gasket
material is available from your Authorized
HearthStone Dealer.
Step 1. Allow the Tucson to cool completely.
Step 2. Open the door. Using a 1/8" allen wrench
remove the door screw by turning counterclockwise.
Step 3. Remove the existing gasket by grasping one
end and pulling firmly.
Step 4. Use a wire brush or the tip of a screwdriver to
clean the channel of remaining gasket.
Step 5. Determine the correct length of the
appropriate-sized gasket by laying it out in the
channel. Allow an extra 1" to 2" ( 25-50 mm), and
mark the spot to be cut.
Step 6. Cut the gasket at the marked spot with a
utility knife. Twist the ends slightly to prevent the
gasket from unraveling.
Step 7. Apply water glass adhesive to the gasket
channel.
Step 8. Starting at one end, press the gasket into the
channel. Ensure a good joint where the gasket ends
meet before trimming any excess. Do not overlap the
gasket ends or leave ends with ragged edges.
Step 9. Firmly and evenly press the gasket to seat it
in its channel.
Cleaning the Glass
If operating on propane, it may be necessary to clean
the inside of the glass occasionally. Do not use
abrasive cleaners, steel wool, or a razor blade.
Scratching the glass will weaken the integrity. Your
dealer will usually stock a gas fireplace glass cleaner
or a window cleaning fluid will work adequately. Do
not clean when hot!!
WARNING: Do not operate this appliance with the
glass panel removed, cracked or broken. Replacement
of the panel should be done by a licensed or qualified
service person. Contact your authorized dealer for
replacement glass.
WARNING: Do not substitute Materials.
For replacement parts, or for information about parts
or service, contact your local HearthStone dealer. For
the name of the dealer nearest to you, phone or write:
HearthStone Quality Home Heating Products, Inc.
317 Stafford Avenue
Morrisville, Vermont 05661-8695
E-Mail:[e-mail]

OWNER’S MANUAL MODEL: 8740 TUCSON Vent-Free ROOM HEATER
-19-
SIDE VIEW
FIGURE 19
FRONT VIEW
26.5"
21"
20"
PARTS LIST
Part # Description
2710-115 bottom
2710-220 ash lip
2710-321 right side
2710-326 left side
2710-420 exhaust baffle
2710-486 heat exchanger
2710-511 front door
5710-170 door hinge with bracket
5710-180 door latch bracket
2710-560 glass ret frame
2710-581 front grill
2710-810 top grill
2710-818 top
2710-655 handle, door
1741-350 top side stones 3
5 /16 " x10 5 /16"
1741-351 side stones 7½" x 6½"
1741-352 top center stone 8
e " x 3 e "
7211-554 rear log
7211-555 middle log
7211-556 front log
7211-557 top log
7211-558 charcoal ember (2 oz.)
5320-070 ember screen
5710-119 light shield
5710-120 back light shield
7000-015 thermostat wire
7200-506 thermostat
7000-200 3-way on/off switch
Part # Description
5710-121 valve bracket support
5710-128 valve door
5710-131 ODS pilot bracket
5710-152 burner tube holder
5710-160 log set holder
5710-470 stone clips
5710-511 firebox / air plenum
5710-515 exhaust baffle holder
5710-530 cat. heat shield
5710-597 back shroud
7200-120 burner orifice #55
7200-145 burner orifice #45
7211-005 ¾" Dia. gas line
7211-227 burner tube
7211-301 gas valve sit (NG)
7211-305 gas valve sit (LP)
7211-324 ODS pilot (NG)
7211-327 ODS pilot (LP)
7210-103 piezo igniter
3030-027 glass 13-3/16" x 11¼" x 5 mm
3010-157 catalyst combustion assembly
3160-080 ¾" tape (glass)
3110-057
d " low density door rope
SPECIFICATIONS
Listed:
Vent-Free Gas-Fired Room Heater
Model:
Tucson Vent-Free Room Heater
Tested to:
ANSI Z21.11.2-1993, AGA 5-95
Testing Agency:
Intertek Testing Services NA Inc. (ITS)
Conditionally approved for purchased mobile home
installation.
Natural Gas LP
Input rating (Btu/hr) 20,000 19,500
Maximum output (BTU/hr) 19,000 19,000
Minimum input rating (Btu/hr) 12,500 15,500
Orifice size DMS 45 55
Man. pressure-HI setting (in. w.c./kPa) 3.5/0.87 10.0/2.48
Man. Pressure-Lo setting (in.w.c./kPa) 1.6/0.42 6.4/1.59
Inlet pressure-HI (in. W.c./kPa) 10.5/2.6 14.0/3.47
Inlet pressure-LO (in. W.c./kPa) 5.0/1.24 11.0/2.88