HearthStone Sterling-Ht 8532 Troubleshooting guide

Sterling Ht Model 8532
Manual: 6400-40428
Revised: 5/31/11
Sterling-Ht (Model 8532)
GAS-FIRED DIRECT VENT HEATER
Owner’s Manual
& Installation Guide
Operate and Maintain This Gas Heater
According To This Instruction Manual
Read This Manual in Its Entirety
WARNING: If the information in these instructions
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 near this or any
other gas appliance!
WHAT TO DO IF YOU SMELL GAS:
Do not try to light any appliance.
Do not touch electrical switches; do not use the
phone in your building.
Immediately call your gas supplier from a
neighbor’s phone. Follow your gas supplier’s
instructions.
If you cannot reach your gas supplier, call the fire
department.
A qualified installer, service agency, or gas supplier
must perform installation and service. In the
Commonwealth of Massachusetts, all installation of
gas lines and gas fitting shall only be done by a
licensed gas fitter or licensed plumber.
AVERTISSEMENT: Assurez-vous de bien suivre les
instructions donné dans cette notice pour réduire
au minimum le risque d’incendie ou pour éviter tout
dommage matéeriel, toute blessure ou la mort.
Ne pas 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.
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 service doit être exécuté par un
qualifié installer, agence de service ou le
fournisseur de gaz.

Hearthstone Quality Home Heating Products, Inc STERLING-Ht Model 8532
INFORMATION SHEET
Use this page to record al l relevant information con cerning the purchase, installation, and maintenance of your
STERLING Ht Model 8532 Gas-Fired Direct Vent Heater. This information will facilitate servicing, purchase of
replacement parts, and warranty claims (if nece ssary). Keep your original re ceipt in a saf e 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 STERLING heater. Retain this manual for future
reference.
SERVICE RECORD
Date Who Performed Work Work Performed Notes:
WHAT WHEN
Firebox cleaning............. annually
Glass cleaning................ as needed
Door Gasket.................... Replacement as needed
1

Hearthstone Quality Home Heating Products, Inc STERLING-Ht Model 8532
2
WELCOME
Congratulations on your purchase of Hearthstone’s
Sterling Ht Gas-Fired Direct Vent heater. The
Sterling incorporates the latest in balanced vent gas
technology, which will provide you with clean,
efficient heat for years to com e. Combustion air
comes directly from the outside of you r home to the
sealed firebox system, eliminating the potential for
annoying back drafts or other problems associated
with home depressurization. The com bination of
natural stones with cast iron gives the Sterling a
pleasing look, which can be maintained with
minimum care.
The Sterling will provide you with years of practical
and convenient service. However, as with an y gas
appliance, the unit must be properly and safely
installed and maintained by qualified service
personnel to ensure safe and trouble-free operation.
READ THIS OWNER’S MANUAL
Operate and maintain this gas heater according to the
instructions in this m anual. Read this manual in its
entirety.
THIS HEATER MUST BE INSTALLED AND
MAINTAINED BY QUALIFIED SERVICE PERSONNEL
Verify the gas connections, and venting systems with
requirements of local, regional, or natio nal
installation codes. Qualified service personnel must
inspect the gas heater before use, and at least
annually.
ALWAYS VENT TO THE OUTSIDE
Never vent the gas heater to other rooms, or
buildings. Do not con nect this gas appliance to a
chimney flue serving a s eparate solid-fuel burni ng
appliance.
MANUFACTURED BY:
Hearthstone Quality Home Heating Products, Inc.
317 Stafford Avenue
Morrisville, Vermont 05661-8695
USA
E-mail: [e-mail]
Web: www.Hearthstonestoves.com
TABLE OF CONTENTS
WELCOME .................................................. 2
OWNER’S INFORMATION............................ 4
LIGHTING INSTRUCTIONS .................................4
DAILY OPERATIONS .........................................4
INSTALLER’S INFORMATION ...................... 5
UNPACKING AND INSPECTION ..........................5
STOVE DIMENSIONS & CLEARANCES TO
COMBUSTIBLES................................................6
VENTING INFORMATION...................................9
ATTACHING YOUR VENTING..........................15
GAS CONNECTIONS .................................. 16
LOG PLACEMENT ...........................................17
INSTALLATION OF THE LOG SET.....................17
REMOVAL OF THE LOG SET............................18
LIGHTING THE UNIT THE FIRST TIME ..... 19
ODORS AND IMPURITIES.................................19
PREPARE FOR LIGHTING.................................19
INITIAL ADJUSTMENTS...................................19
LIGHTING INSTRUCTIONS ...............................19
TURNING OFF THE UNIT.................................20
PILOT AND BURNER FLAMES ......... 20
VARIABLE OUTPUT CONTROL........................20
GAS CONVERSIONS................................... 21
ROUTINE MAINTENANCE AND CARE ....... 22
PARTS LISTS ............................................. 24
TROUBLESHOOTING GUIDE ..................26

Hearthstone Quality Home Heating Products, Inc STERLING-Ht Model 8532
3
SERVICE CAUTION
Any shield, door, or other component removed for
servicing must be replaced prior to o perating. Any
components of the stove rem oved for servicing m ust
be replaced prior to operating. If you believe y our
Sterling is not perform ing properly, immediately
discontinue operation until the unit has been
inspected and approve d by qualified service
personnel. Prior to servicing the unit, turn the valve
control knob clockwise to “OFF”. Ensure the unit is
cool before servicing and cleaning. Any safety
screen, guard, or component removed during
servicing must be r eplaced before operation. Do
not use any components other than those approved
by Hearthstone Quality Home Heating Products,
Inc., otherwise all warranties are void. Do not
substitute components!
FIRE HAZARD
Do not store or use gasoline, or oth er flammable
vapors or liquids near this appliance. The Sterling
should be l ocated out of traffic, and away from
furniture, draperies, clothing, an d other flammable
materials.
SHOCK HAZARD (IF EQUIPPED WITH ACCESSORY FAN)The
accessory blower is equipped with a three-prong
(grounding) plug for protection against shock hazard
and must be plugged directly into a properly
grounded three-prong receptacle. Do not cut or
remove the grounding prong from the plug.
HOT SURFACES
Certain exposed surfaces of the Sterling will reach
high temperatures during n ormal operation.
Clearances to combustibles must be maintained, as
specified in the “Clearances To Co mbustibles”
section of this manual. Due to high tem peratures,
the appliance should be located out of traffic an d
away from furniture, draperies, clothing, and
other flammable materi als. Children and adults
should be al erted to the hazards of high surface
temperatures and m ust stay away to avoid burns
to skin or possible cloth ing ignition. Ensure tha t
young children ar e carefully supervised when in
the same room as the appliance. Clothing or other
flammable material must not be placed on or near
the appliance. (Surveille les enfants. Garder les
vêtements, les meubles, l’essence ou autres liquides à
vapeur inflammables lin de l’appareil.) Clean the
area around, under, and b ehind the unit on a regular
basis to prevent the accumulation of dust and lint.
WARNING: do not operate the appliance
with the fr ont glass removed, cracked, or
broken. Replacement of glass sh ould be
done by a licensed or qualified service
person. Only open front fo r routine
service. Do not slam, or strike the glass.
WARNING: A qualified service t echnician
should do installation, and repair. A qualified
service technician must inspect the appliance
before use, and at least annuall y. More frequent
cleaning may be required due to excessive lint
from carpeting, bedding material, pets, etc. It is
imperative that the c ontrol compartments,
burners, and circulating air passag es of the
appliance are kept clean and free of obstructions.
(S’assurer que le brûleur et le compartiment des
commandes sont propres. Voir les instructions
d’installation et d’utilisation qui accompagnent
l’appareil.)

Hearthstone Quality Home Heating Products, Inc STERLING-Ht Model 8532
4
OWNER’S INFORMATION
The installation must conform with local codes or, i n
the absences of local codes, the current National Fuel
Gas Code, ANSI Z223.1 ( NFPA 54), or CAN/CGA
B149 Installation Code. (Installer l’appareil selon les
codes ou règlements locaux, ou, en l’absence de tels
règlements, selon les Codes d’installation CAN/CGA-
B149.)
Warning: Do not use this appliance 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 that has
been under water. (Ne pas se servir de cet appareil
s’il a été plongé dans l’eau, complètement ou en
partie. Appeler un technicien qualifié pour inspector
l’appareil et remplacer toute partie du système de
contrôle et toute commande qui ont été plongés dans
l’lau.)
Certified for use by:
Board of State Examiners of Plumbers and Gasfitters
100 Cambridge Street, Room 1511
Boston, Massachusetts 02202
LIGHTING INSTRUCTIONS
The gas control knob is located on the top of the
stove, in the rear, right-hand corner.
1. Set the on/off/T-stat switch or thermostat to the
off position.
2. Unplug the blower accessory, if so equipped
3. Push in and turn gas control knob clockwise to
“OFF”. (If not previously lit, the knob should be
in this position.)
4. Wait (5) five minutes to clear out any gas. If you
then smell gas, STOP! Smell all around the
appliance area for gas. Be sure to smell next to
the floor because some gases (LPG) are heavier
than air and will settle on the floor. If you smell
gas immediately follow the What To Do If You
Smell Gas! warning on the cover of this Manual.
If you do not smell gas, go to the next step.
5. Turn gas control knob counterclockwise to
“PILOT”.
6. Push in control knob all the way and hold in.
(You should hear the clicking of the igniter in the
firebox) Verify ignition of the pilot. 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. Pilot should remain lit. If the pilot
goes out, repeat the operation.
If 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 “OFF” and call a
qualified service technician or gas supplier.
7. Turn gas control knob counterclockwise to
“ON”.
8. Select “ON” or “T-STAT” position on the
on/off/t-stat switch.
9. Plug in the blower accessory, if so equipped.
10. Set thermostat to “ON” and set the desired
temperature setting.
Normally, if the “T-STAT” position was selected, the
main burner is cycled on and off by the Thermostat
or the “on”, “off” switch located on the bottom of the
Thermostat body.
TO TURN OFF THE GAS TO THE APPLIANCE
Turn the ga s control k nob clockwise to “OFF”
position. If s hutting the unit off for the non-heating
season, this will improve the overall efficiency of the
unit as the heat from the p ilot is wasted in the
summer. W hen putting the unit back into service
follow the lighting instructions described on thi s
page.
VARIABLE OUTPUT CONTROL
The gas con trol valve is equipped with a variable
output control. This contr ol varies the rate of heat
produced by the unit by vary ing the gas pressure to
the ember burner.
DAILY OPERATIONS
The homeowner can easily operate the Sterling gas-
fired heater. The unit comes wit h a standard
thermostat. Remote thermostats, or wall switches are
available for purchase fr om your local Hearthstone
dealer. Once the therm ostat is installed and properly
adjusted, the desired room temperature is maintained.
By adjusting the variable output contr ol 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, whil e choosing a
high flame setting will result in a short er, hotter burn
cycle. Thr ough trial an d error, the h omeowner can
select the optim um flame size for thei r setting and
application. Also available is a variable speed blower.
(Kit# 95-57320)

Hearthstone Quality Home Heating Products, Inc STERLING-Ht Model 8532
5
INSTALLER’S INFORMATION
Codes
Adhere to ALL local codes or, in their absence, the
latest edition of THE NATIONAL FUEL GAS
CODE ANSI Z223.1 (NFPA 54) or CAN/CGA B1 49
Installation Code, 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
The appliance, when inst alled, must be el ectrically
connected and grounded in accordance with local
codes or, in the absenc e of local co des, with the
current NFPA 70-National Electrical Code or CSA
C22.1-Canadian Electric Code.
A manufactured home (mobile) OEM installation
must conform with the Manufactured Ho me
Construction and Safety Standard, Title 24 CFR, Part
3280 (U.S.) or Standard for Manufactured Ho me
Installation, ANSI/NCBCS A225.1 or Standard for
Gas Equipped Recreational Vehicles and mobile
Housing, CSA Z240.4 .CAN/SCA Z240 M H
(Canada). (Installer l’appareil selon les codes ou
règlements locaux, ou, en l’absence de tels
règlements, selon les Codes d’installation CAN/CGA-
B149.)
FIBER LOG SAFETY INFORMATION
If the decorative fiber logs supplied with the Sterling
are damaged, they must be replaced. The
manufacturer, through your local Hearthstone dealer,
supplies replacement parts. Do not replace fiber logs
with any materials not approved by Hearthstone
Quality Home Heating Products, Inc.
UNPACKING AND INSPECTION
Unpack and Inspect for Damage
The Sterling is packaged by the m anufacturer to
withstand normal shipment without dam age.
However, damage can still occur during transit, so
take care to inspect for damage when unpacking and
installing the unit. If any damage, or a missing part, is
detected, immediately contact y our dealer. Do not
install or put into service a damaged or incomplete
heater.
The unit should appear to be square and level. The
sheet metal parts should be smooth and free of bend s
or dents. The ena meled cast iron should be free of
chips or cracks. If visible or concealed damage is
found, contact your dealer.
The decorative fiber logs supplied with the Sterling
are located in the firebox. Alway s use great car e
when handling the decorative fiber logs, as they are
very fragile and subject to damage and breakage. To
open the front, grasp both sides of the front cast
facade, toward the bottom, and lift upward and then
outward. The bottom will slide up an d out. The
whole piece is then easil y removed. Set the front
aside taking care not to chip or scratch the enamel .
Next, locate the two rotating clips above the glass.
Rotate the clips out of the “locked” position and tilt
the top of the glass outward. Lift the e ntire glass up
and out. The log set can now be inspected for
damage. To take the unit off the pallet, rem ove the
lag bolts, which fasten th e unit to the pallet. Tak e
care not to chip the enameled legs. H ave someone
help lift the stove off the pallet, and set it into place.
Packing List
1-Sterling Gas-fired Heater containing:
3-Decorative Fiber Logs
1- Bag Platinum Bright Embers
1-AA Battery
1-Owner’s Manual and Warranty Card
1-Thermastat and wire
1-LP Conversion kit

Hearthstone Quality Home Heating Products, Inc STERLING-Ht Model 8532
WARNING! Do not oper ate the stove with
the glass front remov ed, cracked, or
broken.
6
ITEMS REQUIRED FOR INSTALLATION
* External regulator (for propane/L.P.G. only)
* Piping which complies with all codes
* Pipe sealant approved for use with propane/L.P.G.
(resistant to sulfur compounds)
* Manual shutoff valve
* Sediment trap (page 16)
* Tee joint
* Pipe wrench
* Phillips head screwdriver
* Other parts as required by local code
*Safety Glasses
*Gloves
*Stone Set
AIR SUPPLY
The Sterling Direct-vent does not requi re additional
installer provided ventilation.
STOVE DIMENSIONS & CLEARANCES TO
COMBUSTIBLES
Always maintain clearances around the stove, as
shown in the Clearan ces to Com bustibles figures.
This allows for adequate ventilation.
Sterling Dimensions
If this appliance is to be installed on carpeting, vinyl
tile or combustible material other than wood flooring,
it must be installed on a metal or wood panel extending
the full width and depth of the stove.

Hearthstone Quality Home Heating Products, Inc STERLING-Ht Model 8532
7
18" (458mm)
3" (76mm)
14" (355mm)
3" (76mm)
Corner Installations
2" (51mm)
Floor
4" (102mm)
2" (51mm)
Parallel Installations 1" (26mm)
2" (51mm)
Mantel Installations
CLEARANCE TO COMBUSTIBLES
SPECIFICATIONS:
LISTED: DIRECT VENT GAS HEATER
Model: 8532-Sterling Ht DV
Testing Agency: Intertek Testing Services NA, Inc. (ITS)
Tested to: ANSI Z21.88-1998CSA 2.33-M98 CAN/CGA 2.17
* You may keep your orifices the same if you wish to burn at the lower 33,000 btus with the top exit kit.
Venting Exit Type Rear Exit – 5”x8” Pipe *Top Exit – 4”x6” Pipe
Gas Type NG LP NG LP
Input rating (Btu/hr) 0-2000ft 33,000 33,000 38,000 38,000
Maximum output (Btu/hr) 0-2000ft 26,600 27,400 30,200 31,300
Minimum input rating (Btu/hr) 13,600 11,900 13,900 11,600
Orifice size DMS 0-2000ft 43,52 55,63 38,51 53,63
Man. pressure- HI setting (in.w.c./kPa) 3.5/0.87 10.0/2.48 3.5/0.87 10.0/2.48
Man. pressure- LO setting (in.w.c./kPa) 1.2/0.3 3.3/0.8 1.2/0.3 3.3/0.8
Minimum inlet pressure (in.w.c./kPa.) 5.0/1.24 11.0/2.88 5.0/1.24 11.0/2.88
Maximum inlet pressure (in.w.c.) 7.0 13 7 13

Hearthstone Quality Home Heating Products, Inc STERLING-Ht Model 8532
8

Hearthstone Quality Home Heating Products, Inc STERLING-Ht Model 8532
VENTING INFORMATION
The Sterling is approved for installation only
with the following venting manuafcturers
products.
Simpson Dura-vent Direct Vent GS
AmeriVent Direct
Secure Vent systems
9
Selkirk Direct-Temp™
EXCELDirect
WARNING
This appliance must not be connected to a chimney
flue serving a separate solid-fuel burning appliance.
The Sterling can be vented two ways:
A) Straight out the back exit, using 5”x8” pipe.
B) Top exit, using kit #95-60320. If you want to
run your vent vertically, you must buy this
vertical vent kit which will convert the venting
pipe to 4"x6". The restrictor will be part of this
kit. No restrictor is needed for a horizontal
exit.
When referring to the rest of this section ensure
which way your unit is being vented.
APPROVED VENTING SYSTEM
COMPONENTS
Component Description
90 0 Elbow
45 0 Elbow
6" Straight
9" Straight
12" Straight
24" Straight
36" Straight
48" Straight
11"-14 5/8" Adjustable Pipe Length
Horizontal Vent Cap
Vertical Vent Cap
Snorkel 36”
Vinyl Siding Standoff 4 x 6 5/8”
Round Ceiling Support Wall
Thimble Covers
Wall thimble
If the vent air intake s ystem, for any reason, is
disassembled, it m ust be reinstalled per the
instructions provided for in the initial installation.
Allowable Venting Configuration Graphs
When determining the venting configuration, you
must consider the position of the termination cap.
There are 5 possible categories.
A) Fireplace & Existing chimney
installation
B) Horizontal termination for 5”x8” pipe
C) Horizontal termination for 4”x6” pipe
D) Vertical termination straight or 2 45O
elbows (4”x6” pipe only)
Note:
If the unit is vented vertically, 4”x6” pipe
must be used.
If using Top Exit Kit, a 24” section of pipe
must be used directly off of stove.
E) Vertical termination, 1 or 2 90 O elbows
(4”x6” pipe only)
Every venting configuration must fall into one of
these categories.
The vent/air intake termination clearances above the
high side of an angled roof as follows:
The termination cap must not
be recessed into a wall or
ceiling.
Roof Pitch Feet Meters
Flat to 6/12 1 0.3
7/12 to 9/12 2 0.6
10/12 to 12/12 4 1.2
13/12 to 16/12 6 1.8
17/12 to 21/12 8 2.4
Termination Clearances
Horizontal
Overhang
Termination
Cap
Vertical Wall

Hearthstone Quality Home Heating Products, Inc STERLING-Ht Model 8532
A. Fireplace & Existing Chimney Installation
The use of an existing chimney as an air intake is not covered under the ANSI Z21.88-1998•CSA 2.33-M98
test methods and the resulting ITS/WHI product certification. The Code Authority Having Jurisdiction must
be consulted prior to proceeding with this installation method.
10

Hearthstone Quality Home Heating Products, Inc STERLING-Ht Model 8532
B. Horizontal Terminations for 5"x 8" Pipe.
11

Hearthstone Quality Home Heating Products, Inc STERLING-Ht Model 8532
12
C. Horizontal Terminations for 4"x 6" Pipe (Requires the use of Top Exit Kit, # 95-60320)
Note: All top exit configurations require a minimum of a 24” section of pipe directly off the unit.

Hearthstone Quality Home Heating Products, Inc STERLING-Ht Model 8532
D. Vertical Terminations - Straight or (2) 45O Elbows (4"x 6” Pipe Only)
13

Hearthstone Quality Home Heating Products, Inc STERLING-Ht Model 8532
E. Vertical Terminations - (1) or (2) 90O Elbows (4"x 6" Pipe)
14

Hearthstone Quality Home Heating Products, Inc STERLING-Ht Model 8532
15
ATTACHING YOUR VENTING
Follow the instructions in either of the 5”x8”
starter kits. If you are attaching the Top Exit kit,
(#95-60320) for vertical v enting configurations,
the instructions will be provided with the kit.
INNER COLLAR:
Locate the 8 screw holes where the in ner collar
attaches to the heat exch anger. Attach t he inner
collar and gasket with the 8 screws provided
with the collar.
OUTER COLLAR:
Locate the 8 screw holes where the outer collar
attaches to the heat exch anger. Attach t he outer
collar and gasket with the 8 screws provided
with the collar.
You are now ready to install your venting.
1. Gasket
2. Inner Starter
3. Gasket
4. Outer Starter
VENT RESTRICTOR
hen converting the u nit to a top exit, (4”x6”
pipe), a restrictor is supplied with the kit.
supplied with our restrictor
e
middle of the stove to
position which corresponds to the ap propriate
roximate
locations of the settings 1-3; however it can be
set in any position. Ti ghten the screw in the
desired setting.
Note:
These positions are based on lab results and can
have some variance.
IF the vent-air intake s ystem is disasse mbled for
any reason, reinstall per the instruction provided
for the initial installation.
The flow of combustion and ventilation air
must not be obstructed.
Loosen the Phillips head screw and rotate th
locator, found on the rear
a
chart setting. Shown below are the app
W
Instructions for installation of the restrictor are
the kit. To adjust y
for maximum flame appearance, first ensure the
unit is cool before touching any part of the stove
or venting. Refer to the Venting Configurations
for recommended restriction plate positions.
Restrictor Plate Setting Locations

HearthStone Quality Home Heating Products Inc STERLING Ht Gas-Fired Direct Vent heater
Cet appareil peut être installé dans un maison
préfabriquée (mobile) déjà installée à d emeure si les
règlements locaux le permettent.
Cet appareil doit être utilisé uniquement avec les
types de gas indiqués sur la plaque signalétique. Ne
pas l’utiliser avec d’autres gas sauf si un kitde
conversion certifié est installé
3" MIN.
Cap
Nipple
To Equipment
Inlet Tee Fitting
Gas Supply
Inlet
Sediment Trap is required
GAS CONNECTIONS
A top plate and a side cover must be removed to
access the gas control valve. First re move the gas
control valve knobs, b y grasping the knobs firm ly
and gently pulling straight up o n the knobs. Next
remove the six screws holding the top pl ate on. Two
are located on the sides, a nd four are located on top.
To remove the side cover, loosen the two screws
which have holes in the side for acce ssing. Do not
remove these screws, just loosen them.. Slide the
side cover upward and remove. The gas suppl y line
connection is made to the Sterling’s gas control
valve, located on the back of the unit, in the lower
right corner, using a 3/8" NPT fitting. The pipe must
be sized to provide sufficient gas supply to meet the
maximum demand of the unit. The supply line must
include a manual shut-off valve and union so that the
unit can be disconnected for servicing.
Use of a dedicated sedi ment trap is required by code ,
and by Heart hstone. Damage to com ponents caused
by the lack of a sediment trap is not covered by
Conditionally approved for purchased mobile home
installation. This appliance may be installed in an
aftermarket permanently located, manufactured
(mobile) home, except where prohibited by local
codes.
This appliance is only for use with the type of gas
indicated on the rating plate. This appliance is not
convertible for use with other gases, unless a
certified kit is used, available through your local
Hearthstone dealer.
16

HearthStone Quality Home Heating Products Inc STERLING Ht Gas-Fired Direct Vent heater
warranty.
Once connected to the gas supply , the gas inlet
pressure, and m anifold gas pressure, must be tested.
The gas control valve has built in pressure taps for
test gauge connections. The supply line pressure must
be tested to ensure it meets the minimum pressure for
the type of fuel in use (NG or LP).
Pressure Measurements: To measure the gas
pressures, connect a manometer to th e gas inlet tap
(6) and manifold pressure tap (7) in the Valve
Description Figure.
GAS PRESSURE ADJUSTMENT
A qualified technician must connect the heater to the
gas supply, and leak test the unit before it is approved
for use. Consult all applicable codes. The appliance,
and its main gas valve, must be isolated from the gas
supply piping system by closing its individual manual
shutoff valve during any pressure t esting of the gas
supply piping system at test pressures equal to o r
greater than ½ psig (3.5kPa).
REPLACING THE GLASS
To replace the front glass, first shut the pilot light off.
Next remove the front cast and glass assembly, as
described in Installation of Log Set s ection. If the
glass is broken, pull the broken fragments of glass
away from the glass fra me using heavy-duty gloves,
as the pieces will be very sharp. Carefully replace the
glass gasket as necessary, and repla ce the glass
assembly and front cast.
WARNING! Do not use substitute materials.
Use only parts that have been sup plied by
Hearthstone, through an authorized
Hearthstone dealer.
CAUTION! Do not clean the glass while the
unit is hot. Allow app roximately one hour
before attempting cleaning.
LOG PLACEMENT
Place only the decorative fiber log set supplied with
the unit in the firebox. This log set is specifically
designed to work with the provided em ber burner.
Do not use any other type of fiber logs, wood logs, or
other materials in the firebox. If the original log set
is damaged, or broken , contact yo ur Hearthstone
dealer for replacement. The decorative fiber log s et
will last a long tim e; however, they will break easil y
if subjected to rough or improper handling.
Exact positioning of the log set is required in order t o
obtain a pleasing fla me pattern a nd efficient
combustion. Incorrect log placement can cause
carbon build-up (soot); excess ther mal stress on the
log set and stove parts, reduced efficie ncy, and high
levels of carbon monoxide. If the log set does not fit
into the fire box exactly as outlined, contact your
dealer for assistance.
INSTALLATION OF THE LOG SET
1) First remove the front cast and glass asse mbly.
To remove the front, grasp both sides of the
front cast fa cade, toward the bottom , and lift
upward and then outward. The bottom will slide
up and out. The whole piece is then easily
removed. Set the fro nt aside taking care not t o
chip or scratch the enam el. Next, locate the two
rotating clips above the gl ass. Rotat e the clips
out of the “locked” position and tilt the top of
the glass outward. Lift the entire glass asse mbly
up and out.
2) Gently take the logs out of the fire box and
remove the bubble wrap from the log set. Be
careful not to damage the log set when
unpacking. There are three logs, a Right, a Left
and a “Twig”.
3) Gently place the Right Log (1) in the firebox, on
the ember burner. The right log has a portion of
twig on the top part of it. On the underside of
the log there is an “L-shaped” cutout that lines
up the log on the ember burner, in the
appropriate position. It should sit as shown.
1
4) Gently place the Left Log (2) in the firebox, on
the ember burner. On the underside of the log
there is an “ L-shaped” cutout that lines up the
17

HearthStone Quality Home Heating Products Inc STERLING Ht Gas-Fired Direct Vent heater
log on the ember burner, in t he appropriate
position. It should sit as shown.
5) Gently place the Twig Log (3) in the firebox, on
the ember burner and agai nst the Right Log (1).
The twig sits in a recess ed part of the e mber
burner, which lines it up, in the appropriate
position. It should sit as shown.
6) Open the bag of Platinum Bright Embers. Fluff
up the pieces, and spread randomly over the logs
and burners. These em bers will glow brightly
when the unit is running.
7) Re-install the glass a ssembly by lining up the
three tabs on the bottom of the assembl y with
the three slots on the fire box. Slide t he lower
portion of the glass as sembly into the slots and
push it flush against the firebox. Rotate the clips
into the “loc ked” position. Re-install the front
cast by sliding the upper portion under the lip of
the top and t ilting the bottom in flush with the
glass assembly. It should then slide downward
and be snug in place. Make sure t he glass
assembly is properly secured to the firebox
before turning the unit on. Be careful not to chip
the enamel when installing the glass assembly or
front cast.
REMOVAL OF THE LOG SET
Caution
Log set retains heat and can be very hot, if
previously lit! Allow 1 hour after pilot light is turne d
off before handling.
2
To remove the log set, follow the Installation of
Log Set instructions in reverse. Place the logs and
in a safe area where they will not be damaged.
CAUTION
Fragile! Handle log set with care.
3
18

HearthStone Quality Home Heating Products Inc STERLING Ht Gas-Fired Direct Vent heater
LIGHTING THE UNIT THE
FIRST TIME
CAUTION: Lighting th e Sterling-Ht for the
first time a nd adjustments to the unit should
be performed only by quali fied service
personnel.
SMOKE AND FUMES WARNING
When lit for the first time, the Sterling will emit some
smoke and fumes. This is norm al “off-gassing” of
the paints an d oils used in the m anufacturing and
assembly of the unit. Open windows to vent the
room if nec essary. The off gassing and fum es will
subside after the first 10 to 20 minutes of operation.
ODORS AND IMPURITIES
A heater of this t ype may produce odors d uring
heater operation due to im purities that may exist in
the immediate area. Sources of i mpurities can be
cleaning solvents, paint s olvents, cigarettes, s moke,
soot from scented candles, pet hair, dust, adhesives,
new carpet, and/or textiles. Such odors will dissipate.
However, opening a wind ow or otherwise providin g
additional ventilation to the area can alleviate th e
condition. If any odor persists, contact your dealer or
an authorized service technician.
PILOT LIGHT
The Sterling has a batte ry operated electric spark
igniter, which ignites the pilot light by m eans of a
spark at the pilot light assembly. To activate the
igniter, turn the gas control knob to ‘Pilot’ and push
and hold it down. You must install the included
battery for the igniter. The battery compartment is
located in the lower rear area of the s tove. Do not
attempt to light t he unit with a m atch or by any
means other than the electric spark.
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 variabl e
output control knob and turn it f ully counter-
clockwise to the highest setting.
INITIAL ADJUSTMENTS
Once the Sterling-Ht is set in place, connected and
assembled as described in the Asse mbly of the Unit,
Electrical Connections, and Gas Suppl y &
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 com pensate for
variations in gas pressure, altitude, and other factors
particular to each installation.
Prior to light ing the unit for the first time, wait 5
minutes to allow any residual gas within the unit t o
dissipate. Smell all around the appliance area for gas.
Be sure to smell next to the floor because some gases
(LP) 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 th e What to Do If
You Smell Gas Warnin g, on the c over of this
manual.
LIGHTING INSTRUCTIONS
The gas control knobs are located at the top, right
rear corner of the unit (see diagram on next page).
1. Set the on/off/T-stat switch or thermostat to the
off position.
2. Unplug the blower accessory, if so equipped
3. Push in and turn gas control knob clockwise to
“OFF”. (If not previously lit, the knob should be
in this position.)
4. Wait (5) five minutes to clear out any gas. If you
then smell gas, STOP! Smell all around the
appliance area for gas. Be sure to smell next to
the floor because some gases (LPG) are heavier
than air and will settle on the floor. If you smell
gas immediately follow the What To Do If You
Smell Gas! warning on the cover of this Manual.
If you do not smell gas, go to the next step.
5. Turn gas control knob counterclockwise to
“PILOT”.
6. Push in control knob all the way and hold in.
(You should hear the clicking of the igniter in the
firebox) Verify ignition of the pilot. Continue to
hold the control knob in for about 20 seconds
after the pilot is lit (ensures thermocouple is up to
temperature). Release the knob and it will pop
back out. Pilot should remain lit. If the pilot goes
out, repeat the operation.
If knob does not pop o ut 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 “OFF” and call a
qualified service technician or gas supplier.
19