HearthStone AURORA SL-26N User manual

Hearthstone Quality Home Heating Products, Inc. ®
ORION 26 Series 8910
Manual: 6400-40492
R: 08/27/18
ORION 26
Series 8910
GAS-FIRED DIRECT-VENT HEATER
OEM Model# SL-26N & SL-26P
Owner's Manual
Installation & Operating
Instructions
Read This Manual in Its Entirety
Operate and Maintain This Gas Heater
According to This Instruction Manual.
SAVE THESE INSTRUCTION
Do not store or use gasoline or other flammable vapors
and liquids in the vicinity of this or any other appliance.
WHAT TO DO IF YOU SMELL GAS:
Do not try to light any appliance.
Do not touch any electrical switch; do not use any
phone in your building.
Leave the building immediately.
Immediately call your gas supplier from a neighbor’s
phone. Follow the gas supplier’s instructions.
If you cannot reach your gas supplier, call the fire
department or 911.
A qualified installer, service agency, or gas supplier must
perform installation and service of this appliance. In the
Commonwealth of Massachusetts, all installation of gas
lines and gas fittings must be performed by a licensed gas
fitter or licensed plumber.
Ce manual est disponible en Francais a
www.hearthstonetech.com
Report #0361GF001S

Hearthstone Quality Home Heating Products, Inc ORION 26 Series 8910
2
POÊLE AU GAZ À VENTILATION DIRECTE
Manuel de l'Utilisateur
Lire ce Manuel en Entier
Utiliser et Entretenir ce Poêle au Gaz
selon ce Manuel d'Instructions
CONSERVER CES INSTRUCTIONS!
Nepas entresposer ni utiliser d’essence ni d’autre
vaperurs ou liquides inflammables dans le
voisinage de cet apprareil ou de tout autre
appareil.
QUE FAIRE SI VOUS SENTEZ UNE ODEUR
DE GAZ:
Ne pas tenter d’allumer d’appareil.
Ne touchez à aucun interrupteur. Ne pas
vous servir des téléphones se trouvant dans
le batiment où vous vous trouvez.
Quittez le bâtiment immédiatement.
Appelez immédiatement votre fournisseur de
gaz depuis un voisin. Suivez les instructions
du fournisseur.
Si vous ne pouvez rejoindre le fournisseur
de gaz, appelez le service dos incendies
L’installation et l’entretien doivent être assurés
par un installateur ou un service d’entretien
qualifié ou par le fournisseur de gaz.

Hearthstone Quality Home Heating Products, Inc ORION 26 Series 8910
3
INDEX
IMPORTANT SAFETY INFORMATION.......................................................................4
SPECIFICATIONS..................................................................................................... .5
INSTALLATION REQUIREMENTS.............................................................................6
MASSACHUSETTS REQUIREMENTS...................................................................... 7
VENTING.................................................................................................................... 8
ASSEMBLY & INSTALLATION.................................................................................. 16
Fuel Conversion................................................................................................26
GAS CONNECTION...................................................................................................19 & 29
LIGHTING AND OPERATION....................................................................................32
MAXITROL CONTROL SYSTEM...............................................................................35
MAINTENANCE..........................................................................................................44
MAINTENANCE LOG FORMS...................................................................................47
INSTALLATION RECORD..........................................................................................48
REPLACEMENT PARTS LIST...................................................................................49
CONTROL SCHEMATIC............................................................................................50
TROUBLESHOOTING................................................................................................51
WARRANTY INFORMATION.....................................................................................53
WE STRONGLY SUGGEST THAT YOU READ THIS MANUAL THOROUGHLY BEFORE
BEGININNG THE INSTALLATION OF THE ORION 26 DIRECT VENT GAS FIREPLACE.
ALTHOUGH THE BASIC REQUIREMENTS FOR THE INSTALLATION OF ALL DIRECT VENT
GAS FIREPLACES ARE SIMILAR, EACH SPECIFIC PRODUCT HAS ITS OWN UNIQUE SET-UP
AND INSTALLATION REQUIREMENTS THAT MUST BE FOLLOWED EXACTLY. PLAN YOUR
INSTALLATION IN ADVANCE BY CAREFULLY REVIEWING ALL THE INFORMATION
CONTAINED IN THIS MANUAL.

Hearthstone Quality Home Heating Products, Inc ORION 26 Series 8910
4
Important Safety Information
The installation must conform with local codes or, in the absence of local codes, with the National Fuel Gas
Code, ANSI Z223.1/NFPA 54, or the Natural Gas and Propane Installation Code, CSA B149.1.
A manufactured home (USA only) or mobile home OEM installation must conform with the Manufactured Home
Construction and Safety Standard, Title 24 CFR, Part 3280 or when such a standard is not applicable, the
Standard for Manufactured Home Installations, ANSI/BCSBCS A225.1, or Standard for Gas Equipped
Recreational Vehicles and Mobile Housing, CSA Z240.4.
The appliance and its appliance main gas valve must be disconnected from the gas supply piping system during
any pressure testing of that system at test pressures in excess of 1/2 psi (3.5 kPa).
The appliance must be isolated from the gas supply piping system by closing its equipment shutoff valve during
any pressure testing of the gas supply piping system at test pressures equal to or less than 1/2 psi (3.5 kPa).
The installation must provide for adequate ventilation air to the appliance.
This gas appliance must not be connected to a chimney flue serving a separate solid-fuel burning appliance.
The appliance, when installed, must be electrically grounded in accordance with local codes, or, in the absence
of local codes, with the National Electrical Code ANSI/NFPA 70, or the Canadian Electrical Code, CSA C22. 1.
The appliance area must be kept clear and free from combustible materials, gasoline and other flammable
vapors and liquids.
The flow of combustion and ventilation air must not be obstructed.
Do not use this appliance if any part has been under water. Immediately call a qualified service technician to
inspect the appliance and to replace any part of the control system and any gas control which has been under
water.
Due to high temperatures, the appliance should be located out of traffic and away from furniture and draperies.
Installation of a TV or, any other electrical appliance, above this fireplace is not allowed.
Children and adults should be alerted to the hazards of high surface temperatures and should stay away to
avoid burns or clothing ignition.
Young children should be carefully supervised when they are in the same room as the appliance. Toddlers,
young children and others may be susceptible to accidental contact burns. A physical barrier is recommended if
there are at-risk individuals in the house. To restrict access to a fireplace or a stove, install an adjustable safety
gate to keep toddlers, young children and other at-risk individuals out of the room and away from hot surfaces.
A barrier designed to reduce the risk of burns from the hot viewing glass is provided with this appliance and
shall be installed for the protection of children and other at-risk individuals.
If the barrier becomes damaged, the barrier shall be replaced with the manufacturer’s barrier for this appliance.
Clothing or other flammable material should not be placed on or near the appliance.
Any screen or guard removed for servicing an appliance must be replaced prior to operating the appliance.
Installation and repair should be done by a qualified service person. The appliance should be inspected before
use and at least annually by a professional service person. More frequent cleaning may be required due to
excessive lint from carpeting, bedding material, etc. It is imperative that the control compartments, burners and
circulating air passageways of the appliance be kept clean.
WARNING: Do not operate the appliance with the glass front removed, cracked or broken. Replacement
of the glass should be done by a licensed or qualified service person.
WARNING: Use only glass assembly, 99-58105 which includes the glass panel, frame and gasket.

Hearthstone Quality Home Heating Products, Inc ORION 26 Series 8910
5
Specifications
Testing Agency: OMNI- Test Laboratories, Inc.
PO Box 301367
Portland, OR 97294
Listed: Direct Vent Gas Heater
Model: ORION 26 - 8910
Tested to: ANSI Z21.88b –2014/CSA 2.33b - 2014
Certified for Canada, CSA P.4.1
Approved for Mobile Home Installation
ORION 26 Dimensions
Specification
NG
LP
Input rating (Btu/hr)
19,000
19,000
Orifice size DMS 0-2000 ft
5/64”
55
Manifold pressure (in.w.c./kPa)
4.8/1.2
10.0/2.5
Minimum Supply Pressure (in.w.c./kPa)
5.5/1.4
11.0/2.8
Maximum Supply Pressure (in.w.c./kPa)
10.0/2.5
13.0/3.3
Minimum Inlet press.(in.w.c./kPa)
5.0/1.25
12.0/2.99
Minimum input rating (Btu/hr)
11,000
11,000
Maximum Observed Steady State Efficiency (%)
78.8
79.5
Steady State Efficiency (%)
65.0
61.4
Annual Fuel Utilization Efficiency (AFUE) (%)
64.2
60.5
Canadian P4 Efficiency (%)
55.1
50.0
It is recommended that the pilot flame be turned off if the appliance will not be in use for an extended period of
time.
This appliance is equipped for use with the fuel type indicated on the rating plate.
This appliance has been certified by OMNI-Test Laboratories, Inc. to ANSI Z21.88-2014/CSA 2.33-2014. Vented
Gas Fireplace Heaters and CAN/CGA-2.17-M91, Gas-Fired Appliances for Use At High Altitudes.
The ORION 26 is approved for installation at elevations up to 2000 feet in the U.S. and 1370 meters (4500 feet)
in Canada without change. If your installation is at an elevation greater than these, consult with the local
authority having jurisdiction for gas product installations to determine their specific requirements for high altitude
installations.
Certified for use by:
Board of State Examiners of Plumbers and Gasfitters
100 Cambridge Street, Room 1511
Boston, Massachusetts 02202
Manufactured and Warranted by:
Hearthstone Quality Home Heating Products, Inc.
317 Stafford Ave.
Morrisville, VT 05661-8695, USA
www.hearthstonestoves.com

Hearthstone Quality Home Heating Products, Inc ORION 26 Series 8910
6
Installation Requirements
Several issues must be addressed when selecting a suitable location for your ORION 26 fireplace. The
minimum clearances to combustible construction are listed below. In addition, access to the gas supply must be
considered. The location of the fireplace will also affect the venting requirements and you must be certain the
location will allow compliance with the venting requirements shown on page 8. You must also insure that your
installation provides adequate accessibility clearance for servicing and proper operation.
Installation and repair should be done by a qualified service person. The appliance should be inspected before
use and at least annually by a professional service person. More frequent cleaning may be required due to
excessive lint from carpeting, bedding material, etc. It is imperative that the control compartment, burners and
circulating air passageways of the appliance be kept clean.
MINIMUM CLEARANCES TO COMBUSTIBLE CONSTRUCTION
Fireplace to L. Side Wall 6” (152mm) Fireplace to Ceiling 8” (203mm)
Fireplace to R. Side Wall 6” (152mm) Fireplace to Rear Wall 0” (0mm)*
Fireplace to Corner Wall 6” (152mm) Fireplace to Floor 3” (76mm)**
Vent Pipe to Adjacent Materials 1.5” (38mm)
*Mounting plate bosses contact the wall
**The minimum required clearance to be maintained from the fireplace to combustible flooring is
measured from the top surface of carpeting, tile, etc.

Hearthstone Quality Home Heating Products, Inc ORION 26 Series 8910
7
The gas fireplace is shipped with a 3/8” tube OD (male) connection. The gas supply piping should have a
separate gas shutoff valve and a 1/8” NPT plugged tapping upstream of the valve. The stove and its main
control valve must be disconnected from the gas supply piping system during any pressure testing of that
system at test pressures in excess of 1/2 psi (3.5 kPa). The stove must be isolated from the gas supply piping
system by closing the main control valve during any pressure testing of the gas supply system at test pressures
equal to or greater than 1/2 psi (3.5 kPa). After the gas supply has been connected, use a commercial gas leak
detector or apply a soapy water solution to all the fittings to check for gas leaks. Never use a flame to test for
leaks.
REQUIREMENTS FOR THE COMMONWEALTH OF MASSACHUSETTS
This product must be installed by a licensed plumber or gas fitter when installed within the
Commonwealth of Massachusetts. If this appliance is installed in a dwelling, building or structure
used in whole or in part for residential purposes and the installation includes a horizontal vent
termination that is less than seven (7) feet above the finished grade in the area of the venting,
including but not limited to decks and porches, a hard-wired carbon monoxide detector with an alarm
and battery back-up must be installed on the floor level of the dwelling, building or structure where
the appliance is to be installed.
Additionally, a hard-wired or battery operated carbon monoxide detector with an alarm must be
installed on each additional level of the dwelling, building or structure served by the appliance. It
shall be the responsibility of the property owner to secure the services of qualified licensed
professionals for the installation of hard-wired carbon monoxide detectors.
In the event that the horizontally vented appliance is installed in a crawl space or attic, the hardwired
carbon monoxide detector with alarm and battery back-up may be installed on the next adjacent floor
level.
In the event that this requirement cannot be met at the time of completion of the installation of the
appliance, the owner shall have a period of thirty (30) days to comply with the requirement. However,
during said thirty (30) day period, a battery operated carbon monoxide detector with alarm must be
installed.
Each carbon monoxide detector as required in accordance with the above provisions must comply
with NFPA 720 and be ANSI/UL 2034 and IAS certified.
In addition when the vent termination is less than seven (7) feet above finished grade a metal or
plastic identification plate must be permanently mounted to the exterior of the building at a minimum
height of eight (8) feet above grade directly in line with the exhaust vent terminal. The sign shall read,
in print size no less than one-half (1/2) inch in size, “GAS VENT DIRECTLY BELOW. KEEP CLEAR OF
ALL OBSTRUCTIONS”.
A COPY OF THESE INSTRUCTIONS PLUS ALL VENTING INSTRUCTIONS WHICH INCLUDE PARTS
LISTS, AND/OR ALL VENTING DESIGN INSTRUCTIONS MUST REMAIN WITH THE STOVE AT THE
COMPLETION OF THE INSTALLATION.
ATTENTION INSTALLERS: Mark below which venting system was used in the installation. These
instructions must remain with the Orion Installation & Operation Manual.

Hearthstone Quality Home Heating Products, Inc ORION 26 Series 8910
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Venting
The ORION 26 Direct Vent Gas Fireplace has been tested and listed for installation with 4” X 6 5/8” Simpson
DuraVent GS/Pro®, Selkirk Direct-Temp®, Security Secure Vent™, AmeriVent Direct™, Metal Fab Direct Vent
and ICC EXCELDirect venting components. Although you may use the pipe components (straight pipe, elbows,
etc.) from any of the listed manufacturers, you may only use the vent terminations (caps) listed in the chart on
page 9. For installations where a snorkel is needed, please note that only three snorkels are approved for use.
Please plan your installation accordingly.
For all specific venting installation requirements, follow the installation instructions included by the venting
manufacturer with the venting system components you have chosen.
Please note:
•For venting configurations that include no vertical rise, a total horizontal vent run of up to 30 inches
(and including one 45° elbow) is allowed. However, if your installation has room to add a vertical pipe
section, we suggest adding at least one foot of vertical rise to the system.
•For venting configurations that include vertical rise, it is assumed that the installation will include at least
one 90° elbow. Up to three additional 90° elbows (or equivalent 45° elbows) may also be used. The
total venting may not exceed 20 feet of vertical rise and/or 10 feet horizontal run. Refer to the venting
charts starting on pages 10 & 11 for specific details while you plan your installation. Note: The number
of elbows impacts the maximum allowable horizontal vent run.
•Many installations will involve venting directly through standard 2 X 4 or 2 X 6 construction exterior wall
to a horizontal vent termination (cap). The vent starter pipe has been designed to accommodate those
two common installations without the use of any additional venting components other than a standard
horizontal cap. See the chart on page 9 for a list of approved vent caps.
•A special corner installation kit (pt# 90-99901 is also available that will allow the ORION 26 fireplace to
be mounted in a corner without constructing a 45° partition wall. This kit is available from your ORION
26 dealer and has its own installation instructions. Please refer to those instructions for specific details
regarding the installation using the kit.
•If the fireplace will be installed on an interior wall or other location that precludes venting directly through
an outside wall to a horizontal vent cap, or if the distance to the outside wall exceeds 30”, one or more
elbows will be required to allow addition of the required vertical venting to the installation. When vertical
venting is required, the fireplace venting may be terminated with either a vertical or horizontal vent cap
depending on the specifics of the installation. Refer to the venting charts starting on pages 9 & 10 for
specific venting requirements and see the chart on page 9 for a list of approved vent caps before you
plan your installation.
•There should be a 1 1/2” overlap of the vent and combustion air tubes, when telescopic joints are used.
•A minimum clear space of 1 1/2” must be maintained around the vent pipe where it penetrates the first
combustible wall adjacent to the fireplace (either the outside wall for the direct-through-the-wall
installation or the partition wall for the 45° or other interior wall installations). The special vent pipe heat
shields that are ORION 26 provided with the must also be installed in the first wall adjacent to the
fireplace. A minimum clear space of 1 1/2” must also be maintained where the vent pipe penetrates any
other interior wall, exterior wall, ceiling or roof.
•The ORION 26 may also be installed in front of an exiting fireplace opening utilizing special co-linear
venting components available from the venting manufacturers. These systems split and then recombine
the co-axial air and exhaust and allow the use of flexible venting. This makes it easier to run the venting
through the narrow fireplace damper opening to the top of the chimney. Refer to the vent
manufacturers’ instructions. Use the vertical venting column (0 feet Horizontal Run) in the venting
charts to determine the required restrictor settings depending on the height of chimney.

Hearthstone Quality Home Heating Products, Inc ORION 26 Series 8910
9
Using Vent Charts
The location of the vent termination must meet the requirements of the current edition of ANSI Z223.1/NFPA
54, National Fuel Gas Code or CAN B419.1, Natural Gas and Propane Installation Code and the
requirements shown on page 15 of this manual.
Just as with any other vented device, vertical vent rise creates draft (negative pressure) in the firebox as the
exhaust gases heat up. If this draft becomes excessive, it can affect the performance or appearance of the fire.
The ORION 26 fireplace includes air and exhaust restrictors that are used to balance the draft in the fireplace to
the optimal level for installations where excessive draft might occur. The venting charts on pages 10 and 11
provide an easy means for determining whether your specific installation requires inlet air or exhaust restrictors
or both. To make the determination about whether air or exhaust restrictors are needed, a venting chart
worksheet is provided on page 12. Follow the instructions and fill in the worksheet for your particular
installation. This will allow you to determine the recommended restrictor settings for your exact installation.
Although this might appear to be a complicated process at first glance, it is really quite straight-forward and the
result will be a fire that looks and performs as intended. Several examples of worksheet calculations are shown
on page 13 to help guide you.
Please be sure to note that:
1. There are separate venting charts for Natural Gas and LP Gas. Refer to the appropriate chart for your fuel
type to determine your specific restrictor requirements. The settings in the charts have been determined
based on extensive testing.
2. Determine the total vertical vent rise and total horizontal vent run for your installation. All measurements are
made from the center of the vent opening in the back of the fireplace.
3. If your fireplace will not be venting directly though an outside wall to a horizontal termination or if more than
30” of horizontal vent run is required, some vertical vent rise will be required for the fireplace to function and
vent properly. Elbows will also be required for those installations. However, installations are limited to a
maximum of four 90° elbows (or 45° elbow equivalents).
4. Note: Two 45° elbows equal one 90° elbow.
5. The recommended restrictor settings in the venting charts allow up to two 90° elbows (or 45° elbow
equivalents) to be used without affecting the restrictor settings. Additional elbows will require that you
calculate a new equivalent horizontal run for your installation to account for the additional flow resistance
caused by the extra elbows. For the purposes of calculating the equivalent horizontal vent run, each
additional 90° elbow is equivalent to three feet of horizontal vent run. The total horizontal vent run including
elbow equivalents cannot exceed 10 feet.
6. The maximum vertical vent rise cannot exceed 20 feet.
7. There are two exhaust restrictors that are provided with your ORION 26 fireplace. They are labeled “A” and
“B”. The A restrictor provides less exhaust restriction than B.
8. An air restrictor plate is also provided with your fireplace. It is a ring with bendable tabs that can be set to
adjust the amount of restriction in the air supply system. Once the appropriate number tabs are bent open
(in accordance with the requirements for your installation), the plate is inserted between the fireplace and
the vent starter pipe.

Hearthstone Quality Home Heating Products, Inc ORION 26 Series 8910
10
Natural Gas Venting Chart

Hearthstone Quality Home Heating Products, Inc ORION 26 Series 8910
11
LP Gas Venting Chart

Hearthstone Quality Home Heating Products, Inc ORION 26 Series 8910
12
Venting Chart Worksheet
A. FUEL TYPE: NATURAL GAS LP GAS (PROPANE)
B. TOTAL VERTICAL VENT RISE (MEASURED FROM HORIZONTAL CENTERLINE OF VENT OPENING ON
THE BACK OF THE FIREPLACE TO THE HORIZONTAL CENTERLINE OF THE VENT CAP (FOR HORIZONTAL
VENT CAPS) OR TO THE FLANGE ON THE CAP (FOR VERTICAL CAPS)): _____________ FEET
C. TOTAL HORIZONTAL VENT RUN (MEASURED FROM THE VERTICAL CENTERLINE OF THE VENT
OPENING ON THE BACK OF THE FIREPLACE TO THE FLANGE ON THE CAP (FOR HORIZONTAL CAPS) OR
TO THE VERTICAL CENTERLINE OF THE CAP (FOR VERTICAL CAPS)): _____________ FEET
NOTE: THE VERTICAL VENT RISE AND HORIZONTAL VENT RUN ARE THE OFFSETS IN THE LOCATIONS
OF VENT CAP RELATIVE TO THE VENT OPENING ON THE FIREPLACE. VENT PIPE THAT RUNS AT 45°
HAS BOTH A VERTICAL RISE AND HORIZONTAL RUN. SNORKEL CAPS HAVE BUILT-IN VERTICAL RISE
THAT MUST BE COUNTED.
D. TOTAL NUMBER OF 90° ELBOWS: _______ NOTE: SNORKELS COUNT AS 2- 90° ELBOWS
E. TOTAL NUMBER OF 45° ELBOWS: _______
TERMINATION (CAP) TYPE: HORIZONTAL VERTICAL SNORKEL
VENT BRAND:
Simpson DuraVent GS/Pro®Selkirk Direct-Temp®Security Secure AmeriVent Direct™
Metal Fab Direct Vent ICC EXCEL Direct
VENT CAP MODEL NO: _______________ NOTE: SEE APPROVED VENT CAPS ON PAGE 8
EXHAUST AND AIR INLET RESTRICTORS CALCULATOR
A. Fuel Type ________
B. Total Vertical Vent Rise: ________ feet
C. Total Horizontal Vent Run (Actual): ________ feet
D. 90° Elbows Needed: ________
E. 45° Elbows Needed: ________
F. Total 90° Elbows Equivalent: D +(E x ½) = ________
G. 90° Elbows in Excess of 2: F - 2 = ________
H. Additional Horiz. Feet Equivalent: G x 3 = ________ feet
I. Horizontal Vent Run (Equivalent): C + H = ________ feet
Find _____ Chart Settings for:
B._________ feet Vertical Rise and I.________ feet Horizontal Run (Equivalent).
Exhaust Restrictor Required: N Y IF YES: A or B
Air Restrictor Required: N Y IF YES: Number of Tabs Open: _______

Hearthstone Quality Home Heating Products, Inc ORION 26 Series 8910
13
Venting Chart Worksheet Examples
A. Fuel: Natural Gas
B. Total Vertical Vent Rise: 0feet
C. Total Horiz. Vent Run (Actual): 0 feet
D. 90° Elbows Needed: 0
E. 45° Elbows Needed: 0
F. Total 90° Elbows Equivalent : 0
G. 90° Elbows in Excess of 2: 0
H. Additional Horiz. Feet Equivalent 0
I. Total Horizontal Vent Run (Equivalent): 0
Use Natural Gas Chart Settings for:
0feet Vertical Rise, 0feet Horizontal Run.
Exhaust Restrictor Used: Restrictor Not Used
Air Restrictor Tabs Open: Restrictor Not Used
A. Fuel: LP Gas
B. Total Vertical Vent Rise: 1feet
C. Total Horizontal Vent Run (Actual): 3 feet
D. 90° Elbows Needed: 2
E. 45° Elbows Needed: 0
F. F. Total 90° Elbows Equivalent: 2+(0 x ½) = 2
G. 90° Elbows in Excess of 2: 2 - 2 = 0
H. Additional Horiz. Feet Equivalent: 0 x 3 = 0
I. Total Horiz. Vent Run (Equivalent): 3 + 0 = 3
Use LP Gas Chart Settings for:
1 feet Vertical Rise, 3feet Horizontal Run.
Exhaust Restrictor Used: Restrictor Not Used
Air Restrictor Tabs Open: Restrictor Not Used
A. Fuel: Natural Gas
B. Total Vertical Vent Rise: 12 feet
C. Total Horiz. Vent Run (Actual): 0 feet
D. 90° Elbows Needed: 1
E. 45° Elbows Needed: 0
F. Total 90° Elbows Equivalent : 0
G. 90° Elbows in Excess of 2: 0
H. Additional Horiz. Feet Equivalent 0
I. Total Horizontal Vent Run (Equivalent): 0
Use Natural Gas Chart Settings for:
12 feet Vertical Rise, 0feet Horizontal Run.
Exhaust Restrictor Used: A
Air Restrictor Tabs Open: Restrictor Not Used
A. Fuel: LP Gas
B. Total Vertical Vent Rise: 10 feet
C. Total Horizontal Vent Run (Actual): 7 feet
D. 90° Elbows Needed: 2
E. 45° Elbows Needed: 2
F. F. Total 90° Elbows Equivalent: 2+(2 x ½) = 3
G. 90° Elbows in Excess of 2: 3 - 2 = 1
H. Additional Horiz. Feet Equivalent: 1 x 3 = 3
I. Total Horiz. Vent Run (Equivalent): 7 + 3 = 10
Use LP Gas Chart Settings for:
10 feet Vertical Rise, 10 feet Horizontal Run.
Exhaust Restrictor Required: B
Air Restrictor Tabs Open: 3
A. Fuel: Natural Gas
B. Total Vertical Vent Rise: 6feet
C. Total Horizontal Vent Run (Actual): 6 feet
D. 90° Elbows Needed: 3
E. 45° Elbows Needed: 0
F. Total 90° Elbows Equivalent: 3+(0 x ½) = 3
G. 90° Elbows in Excess of 2: 3 - 2 = 1
H. Additional Horiz. Feet Equivalent: 1 X 3 = 3
I. Total Horiz. Vent Run (Equivalent) 6 + 3 = 9
Use Natural Gas Chart Settings for:
6feet Vertical Rise, 9 feet Horizontal Run.
Exhaust Restrictor Required: A
Air Restrictor Tabs Open: 4
A. Fuel: LP Gas
B. Total Vertical Vent Rise: 2feet
C. Total Horizontal Vent Run (Actual): 10 feet
D. 90° Elbows Needed: 2
E. 45° Elbows Needed: 0
F. Total 90° Elbows Equivalent: 2+(0 x ½) = 2
G. 90° Elbows in Excess of 2: 2 - 2 = 0
H. Additional Horiz. Feet Equivalent: 0 x 3 = 0
I. Total Horiz.Vent Run (Equivalent): 10 + 0 = 10
Use LP Gas Chart Settings for:
2 feet Vertical Rise, 10 feet Horizontal Run.
Exhaust Restrictor Used: Restrictor Not Used
Air Restrictor Tabs Open: 3 1/2

Hearthstone Quality Home Heating Products, Inc ORION 26 Series 8910
14
The illustration below shows some of the many ways the ORION 26 fireplace may be installed in the home.
This includes interior and exterior wall installations, corner installations and horizontal and vertical vent
terminations.
HORIZONTAL
TERMINATION
VERTICAL
TERMINATION

Hearthstone Quality Home Heating Products, Inc ORION 26 Series 8910
15
Vent Terminal Clearances
Assembly and Installation
UNPACKING AND INSTALLING THE ORION 26 WALL MOUNT FIREPLACE
The fireplace components are shipped in three cartons. By now, you will have opened the top of the first carton,

Hearthstone Quality Home Heating Products, Inc ORION 26 Series 8910
16
removed the glass protector and this manual. You will also have found the Left and Right decorative panels.
The second carton contains the vent starter pipe, vent heat shields and air and exhaust restrictors. The third
carton contains the fireplace surround.
1. Using the adjacent illustrations as a guide, first lift and remove Tube 1 from the carton containing the
firebox. Carefully unpack the contents of the tube and set aside. This should include the bag of glass
burner media, the remote control handset, a hardware bag and relief door with gasket.
2. Next lift and remove Tube 2 from the carton. Carefully remove the contents of the tube. This includes the
four decorative panels that will be attached to the fireplace during assembly.
3. Next, remove all remaining packaging materials from the carton.
4. Lift the firebox and the fireplace mounting plate as a unit up and out of the carton. The best place to lift is at
sides. Remove the fireplace mounting template from the face of the fireplace. You should now have all of
the parts as shown in the illustration below.
5. Next, unpack the vent starter pipe (with attached gasket), the inner and outer telescoping vent heat shields
and the air and exhaust restrictors from the second carton and set aside for later use.
6. Finally, unpack the fireplace surround from the third carton and set aside on a soft surface for later use.

Hearthstone Quality Home Heating Products, Inc ORION 26 Series 8910
17
Before you begin the fireplace mounting process there are several important installation requirements that must
be met. Careful planning will make the installation easier to accomplish and will reduce the chances of
encountering problems after you start.
1. The fireplace is designed to be wall-mounted using four lag bolts to secure the fireplace mounting plate to
the wall structure. The mounts are located 16” on center to correspond with standard building construction.
If your home has non-standard construction or the location you have chosen for the fireplace does not have
wall studs that correspond to location of the fireplace mounts, modifications to the wall structure will be
needed. It is critical that the four lag bolts that are provided for mounting the fireplace are firmly imbedded
into the wall structure at all four locations.
2. A hole must be provided in the wall for the vent to pass through. The hole must be large enough to provide
1 1/2” clearance around the outside of the vent pipe and to allow for installation of the vent heat shields that
are provided with the fireplace. Follow the hole size requirements that are provided below exactly to avoid
problems. If the location you have chosen does not allow for 1 1/2” clearance to wooden framing in the wall,
modifications to the wall structure must made to obtain the needed vent pipe clearance.
3. All required minimum clearances to adjacent combustible materials (including side walls, ceiling and floor)
must be achieved with the position you have chosen. See the clearance information on page 5. The listed
clearances are measured from the outermost front edges of the fireplace surround and not from the
fireplace body or mounting plate. In addition the requirements for clearance to combustible materials inside
the house, there are specific requirements and limitations that must be met for the location of the vent
terminal relative to doors, windows, corners, eaves, gas supply components and other structural elements of
the house. Please see page 15 for those specific requirements. Again, plan the installation in advance to
avoid problems.
4. The gas supply line must be located within a specific area behind the fireplace.

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Once you are certain that the location you have chosen meets all the necessary mounting and safety
requirements, you can begin the installation.
1. Tape or pin the installation template to the wall in
the position where the fireplace is to be mounted
(see image below) Note: It is important that the
fireplace is mounted in a level position. Use a
spirit level placed on the cross-hairs in the upper
mounting holes on the template and adjust the
template position until the mounting holes are
level. Refer to the adjacent illustration.
2. Next, carefully transfer the location of the two
upper and two lower mounting holes that you will
use for your installation. Use a sharp nail, awl or
pin to pierce the template on the mounting hole
cross-hairs to insure an accurate transfer to your
wall.
3. Next transfer the location for the center of the vent
pass-through hole on the wall. Also transfer at
least one point on the diameter of the vent pass-
through circle. This will make it easier to scribe
the circle later.
4. Finally, transfer the location of the gas supply line.
5. Remove the template and circle the transferred locations with a pencil or marker.
Vent Pass-Through (Parallel Wall Installation on an Outside Wall)
1. An unobstructed wall pass-through is required to allow for a safe installation of the fireplace vent
components. This will necessitate removal of a portion of the interior wall covering (e.g., sheetrock or
plaster and lath), outer wall sheathing and outer wall covering and any adjacent internal wall materials (like
insulation).
2. Scribe a 9 5/8” diameter hole around the vent pass-through center mark using a compass.
3. Use a long drill (1/8” diameter) that is held square and level to the inside wall to transfer the vent pass-
through center location from the inner wall covering through to the outer wall sheathing and outer wall
covering.
4. Carefully cut the inner wall covering along the scribed line and remove the circular wall piece. Note: It is
important to locate electrical wiring in the wall before beginning the installation process. An electrician
should be consulted if there is any question about wiring locations. Failure to locate and protect wiring
during the installation process my result in electrical shock or fire.
5. Remove any insulation materials from wall in the area defined by the pass-through hole.
6. Building codes in your area may require that you add blocking above and below the vent opening. The
blocking should be above and below the 9 5/8” vent opening you made in the wall and should not obstruct
that opening. The blocking should extend to adjacent wall studs.
7. Next, mark and cut a 9 5/8” diameter hole through the outer wall covering and sheathing using the locating
hole you drilled in Step 2.
8. Follow the instructions included with the vent termination (cap) to remove the appropriate amount of outer
wall covering (siding) or to install the vinyl siding shield if used. Do not install the chimney cap at this point.

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Vent Pass-Through (Parallel Wall Installation on an Interior Partition Wall)
1. An unobstructed wall pass-through is required to allow for a safe installation of the fireplace vent
components. This will necessitate removal of a portion of the interior wall covering (e.g., sheetrock or
plaster and lath), on both sides of the partition wall and any adjacent internal wall materials (like insulation).
2. Scribe a 9 5/8” diameter hole around the vent pass-through center mark using a compass.
3. Use a long drill (1/8” diameter) that is held square and level to the inside wall to transfer the vent pass-
through center location from the inner wall covering through to the wall covering on the back side of the
partition wall.
4. Carefully cut the inner wall covering along the scribed line and remove the circular wall piece. Note: It is
important to locate electrical wiring in the wall before beginning the installation process. An electrician
should be consulted if there is any question about wiring locations. Failure to locate and protect
wiring during the installation process my result in electrical shock or fire.
5. Remove any insulation materials from wall in the area defined by the pass-through hole.
6. Building codes in your area may require that you add blocking above and below the vent opening. The
blocking should be above and below the 9 5/8” vent opening you made in the wall and should not obstruct
that opening. The blocking should extend to adjacent wall studs.
7. Next, mark and cut a 9 5/8” diameter hole through the wall covering on the back side of the partition wall
using the locating hole you drilled in Step 2.
8. When installing the fireplace on a partition wall, the venting may be penetrating one or more interior walls,
an exterior wall, the ceiling or the roof.
9. It is important to lay out the locations of all vent pass-through’s before you begin the installation to insure
that the venting will line-up correctly and that the walls and ceiling meet the needed clearances to the vent
pipe.
10. The vent pass-through in the partition wall where the fireplace is mounted must be done in accordance with
the instructions for a parallel wall installation on an outside wall, following steps 1 through 6.
Gas Supply Line
1. Once the vent pass-through (or pass-through’s) are finished, the gas supply line should be installed. The
supply line should exit the wall that the fireplace will be installed on at the location specified on the installation
template We suggest the installation of a shut-off valve in the supply line between the wall and the
connection to the fireplace. Your professional gas installer or local gas company will determine the specific
requirements for the gas supply line as the requirements may vary in different locations. In every case, the
installation must conform with local codes or, in the absence of local codes, with the National Fuel Gas Code,
ANSI Z223.1 or the Canadian Installation Code, CAN/CGA B149.
Vent Pipe Heat Shields
Special telescoping double heat shields for the vent pipe are provided with the ORION 26 fireplace. These
heat shields are a critical part of a safe installation. They are designed to protect combustible materials in
the wall immediately behind the fireplace. The only exception to this is if the corner installation kit (pt# 90-
99901) is used. With the corner kit, the heat shields are installed where the venting passes through the first
adjacent side wall. See the instructions included with the corner kit for specific details.

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Installing the Fireplace Mounting Plate on the Wall
1. The fireplace mounting plate is attached to the wall
structure using four 1/4” X 1 1/2” long lag bolts and large
diameter washers that are provided with the fireplace. It is
important to use the included hardware as the full weight of
the fireplace is supported by the mounting plate.
2. Drill a 5/32” diameter pilot hole at each of the mounting hole
locations that you marked using the template. The pilot
holes should be the full depth of the lag bolts. Be sure that
there is solid wood at each mounting location. If not, the
wall should be reconstructed to provide the needed support.
3. Before the mounting plate can be lagged to the wall the two
tabbed sections of the telescoping vent pipe heat shields
that you set aside earlier must be attached to the mounting
plate. Each heat shield half is held in place with three sheet
metal screws (provided). The inner shield half (smaller
diameter) is installed from the front of the mounting plate.
Slide the inner heat shield half through the vent pipe
opening in the mounting plate. Align the three tabs with the
pilot holes in the mounting plate (as shown in the adjacent
illustration) and install the three screws.
4. The outer vent pipe heat shield half (larger diameter) is
installed on the rear of the mounting plate. Slip the outer
shield half over the inner shield and align and install the
three screws. See the adjacent illustration.
5. The fireplace mounting plate is now ready to be lagged to
the wall structure.
6. With a helper pick up and align the mounting plate over the
gas supply line and line up with the four mounting lag bolt
pilot holes. These holes are in recessed bosses. Use
either the 16” or 24” on center holes depending on the
construction of the wall.
7. Using the lag bolts and washers provided with the fireplace,
install the top lag bolts (with washers) first, followed by the
lower ones. Use a 7/16” socket wrench to tighten the lag
bolts.
Note: It may be helpful to put a light coating of dish or hand soap on the lag bolts to reduce resistance when
tightening.
8. At this point, check to be sure that there is a 5/16” air gap between the entire flat back surface of the
mounting plate and the wall surface. The gap is critical to a safe installation and if the gap is obstructed in
any way, remove the obstruction before proceeding.
9. Next check that the brackets on the mounting plate that actually hold the fireplace are level, again using a
spirit level. If the brackets are not perfectly level, you can adjust the right bracket by loosening the bracket
fasteners and moving the bracket until it is level with the left bracket. Remember to tighten the bracket
fasteners once you have achieved a level position.