COZY HEDV25 User guide

HI-EFFICIENT
DIRECT VENT
WALL FURNACE
- 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.
• 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.
- INSTALLATION AND SERVICE MUST BE PER-
FORMED BYA QUALIFIED INSTALLER,
SERVICE AGENCY OR THE GAS SUPPLIER.
WARNING: If the information in these instructions are
not followed exactly, a fire or explosion may result
causing property damage, personal injury or death.
HEDV25
HEDV40
Remove cabinet to access gas control knob.
WARNING: Operation of this furnace without the properly installed, factory furnished vent system
and vent cap could result in Carbon Monoxide (CO) poisoning and possible death. For your safety,
this furnace and the vent system should be inspected at least annually by a qualified service technician.
This unit is for residential use only and is not approved for installation in greenhouses, or environ-
ments involving dusty, wet, corrosive, or explosive conditions. Such conditions will invalidate the
warranty and may create unsafe conditions.
This appliance may be installed in an aftermarket, permanently located, manufactured home (USA
only) or mobile home, where not 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.
MODEL NUMBERS
NAT. GAS HEDV253A HEDV403A
L.P. GAS HEDV254A HEDV404A
Installation, maintenance, service, trouble shooting and repairs must be performed by a qualified
service agency. Mr./Mrs. Homeowner, do not attempt any of these procedures yourself as this could
expose you to property damage, personal injury, or loss of life and will invalidate all warranties.
INSTALLATION AND
OPERATING INSTRUCTIONS
P/N 72903 / JUNE 2015
INSTALLER: Leave this manual with the
appliance.
CONSUMER: Retain this manual for future
reference.

Page 2
INTRODUCTION
THIS ISAGAS-FIRED DRAFTINDUCED, POWER DEPENDENTDIRECT VENTWALLFURNACE
THAT WILL OPERATE SAFELY AND PROVIDE AN EFFICIENT SOURCE OF HEAT WHEN
INSTALLED, OPERATED AND MAINTAINED AS RECOMMENDED IN THESE INSTALLATION
AND OPERATING INSTRUCTIONS. READ THESE INSTRUCTIONS THOROUGHLY BEFORE
INSTALLING, SERVICING, OR USING THE APPLIANCE. IF YOU DO NOT UNDERSTAND ANY
PART OF THESE INSTRUCTIONS CONSULT LOCAL AUTHORITIES, OTHER QUALIFIED
INSTALLER, SERVICE TECHNICIAN, THE GAS SUPPLIER OR THE MANUFACTURER.
SPECIFICATIONS AND DIMENSIONS
Your Direct Vent Wall Furnace is shipped complete in one carton. This carton contains the furnace, vent
cap, collector box, vent exhaust tube, air inlet tube, wall template with rough-in dimensions, installation
and operating instructions, and wall thermostat.
Introduction…………………………...….. 2
Specifications and Dimensions…………. 2
Safety Rules………………………............. 3
Clearances…………………………..……. 4/5
Location…………………………..….…… 6/7
Installation…………………………...…… 7/9
Lighting Instructions……………….…… 10
Burner Orifice………………………...….. 11
Removing Main Burner…....…………… 11
Proper Burner Flame......………………… 11
Wiring Diagram..........…………………… 12
Sequence of Operation…………...……. 13
Optional Kits……………………….…… 14/16
Maintenance Instr./Service Record…... 17
Trouble Shooting...........……………….. 18/19
Parts Drawing…….....…………………... 20
Parts List ............………………………... 21
Warranty.................................................... 22
CONTENTS
Center
Model Input Type Gas Vent MAX. MIN.
No. BTU/HR Weight Width Depth Height Control CFM AMPS Conn. to Floor Wall Wall
(Adj.) THICKNESS
NATURAL GAS
HEDV253A 25,000 100 Lbs.24-1/2” 9-3/4” 32-1/4” 24 V. 200 1.88 3/8” 12-1/2” 32” 5”
HEDV403A 40,000 120 Lbs.34-5/8” 9-3/4” 30-1/2” 24 V. 500 2.18 3/8” 12-1/2” 32” 5”
L.P. GAS
HEDV254A 25,000 100 Lbs.24-1/2” 9-3/4” 32-1/4” 24 V. 200 1.88 3/8” 12-1/2” 32” 5”
HEDV404A 40,000 120 Lbs.34-5/8” 9-3/4” 30-1/2” 24 V. 500 2.18 3/8” 12-1/2” 32” 5”
The State of Massachusetts requires that installation and service of a gas
appliance be performed by a plumber or gas fitter licensed in the
Commonwealth of Massachusetts.

SAFETY RULES
1. Improper installation, adjustment, alteration, service, or maintenance can cause property damage, bodily
injury, or death.
2. Use in other than a residential application may result in unsatisfactory performance, may create unsafe
conditions and will invalidate the warranty.
3. The installation must conform with local codes or in the absence of local codes wtih the National Fuel
Gas Code, ANSI Z223.1/NFPA 54, Natural Gas and Propane Installation Code, CSA B149.1.
4. DO NOT INSTALLTHIS FURNACE IN ARECREATIONALVEHICLE ORTRAILER.
5. Do not operate wall furnace unless it is connected to the factory supplied vent system with vent cap in
place.
6. Check the rating label attached to the wall furnace to be sure it is equipped for the type gas you intend to
use.
7. Never use a match, candle, flame or other source of ignition to check for gas leaks. Use only soapy water
or liquid detergent.
8. Have your wall furnace and vent system inspected at least annually by a qualified service technician.
9. Before cleaning or servicing, turn off the gas and allow furnace to cool.
10. Do not operate wall furnace without all components properly installed (top, front, etc.).
11. Due to high temperatures, the appliance should be located out of traffic and away from furniture and
drapes.
12. Children and adults should be alerted to the hazards of high surface temperature and should stay away
to avoid burns or clothing ignition.
13. Young children should be carefully supervised when they are in the same room as the appliance.
14. Clothing or other flammable material should not be placed on or near the appliance.
15. INSTALLATION AND REPAIR SHOULD BE DONE BYA QUALIFIED SERVICE TECHNICIAN.
THE APPLIANCE SHOULD BE INSPECTED BEFORE USE AND AT LEAST ANNUALLY BYA
QUALIFIED SERVICE TECHNICIAN. More frequent cleaning may be required due to excessive lint
from carpeting, bedding material, etc. It is imperative that control compartments, burners, and circulating
air passageways of the appliance be kept clean.
16. Do not install in a closet, alcove, or small hallway where the furnace could be isolated from the space to
be heated by closing a door.
17. Do not put anything around the furnace or vent cap that will obstruct the flow of combustion and
ventilation air.
18. The appliance, when installed, must be electrically grounded in accordance with local codes or, in the
absence of local codes, with the latest edition of National Electrical Code, ANSI/NFPA 70, or Canadian
Electrical Code, CSA C22.1, if an external electrical source is utilized.
19. Never operate this furnace without the sight glass in place or with the glass broken or missing.
20. If it is suspected that rising water may enter the furnace, turn off the gas immediately.
21. Do not use this appliance if any part has been under water. Immediately call a qualified service techni-
cian to inspect the appliance and to replace any part of the control system and any gas control which has
been under water.
22. It is necessary to replace damaged gaskets or sealing material within the vent or air intake system. Failure
to do so may result in property damage, personal injury or loss of life.
23. Any safety screen or guard removed for servicing must be replaced prior to operating heater.
24. A gas appliance must not be connected to a chimney flue serving a separate solid fuel burning appliance.
25. The appliance area must be kept clear and free from combustilbe materials, gasoline and other flammable
vapors and liquids.
26. Any safety screen or guard removed for servicing an appliance must be replaced prior to operating the
appliance.
Page 3

VENT TERMINAL CLEARANCES
Page 4
REFERENCE LETTER TO
DRAWING CANADIAN INSTALLATIONS¹ U.S. INSTALLATIONS²
A= Clearance above grade,
veranda,porch, deck, or
balcony
12 Inches (30 cm) 12 Inches (30 cm)
B= Clearance to window or door
that may be opened 12 Inches (30 cm) 9 Inches (23 cm)
C= Clearance to permanently
closed window 12 Inches (30 cm) 9 Inches (23 cm)
D= Verticalclearance to
ventilated soffit located above
the terminal within a horizontal
distance of2 Feet (61 cm)from
the center line of the terminal
18 Inches (46 cm) 18 Inches (46 cm)
E= Clearance to unventilated
soffit 18 Inches (46 cm) 18 Inches (46 cm)
F= Clearance to outside corner 12 Inches (30 cm) 12 Inches (30 cm)
G= Clearance to inside corner 12 Inches (30 cm) 12 Inches (30 cm)
H= Clearance to each side of
center lineextended above
meter/regulator assembly
3 Feet (91 cm) within a height
15 Feet (4.5m) above the
meter/regulator assembly
Clearances are in accordance
withlocal installationcodesand
the requirements of the gas
supplier
I= Clearance to service regulator
vent outlet 3 Feet (91 cm) Clearances are in accordance withlocal installationcodesand
the requirements of the gas
supplier
J= Clearance to nonmechanical
air supply inlet to building or the
combustionairinlet toany other
appliance
12 Inches (30 cm) 12 Inches (30 cm)
K= Clearance to a mechanical
air supply inlet 6 Feet (1.83 m) 3 Feet (91 cm) above ifwithin 10Feet (3 m) horizontally
L= Clearance above paved
sidewalk or paved driveway
located onpublicproperty
7 Feet (2.13m) A vent shall
not terminate directlyabove
a sidewalk or paved driveway
that islocated betweentwo
singlefamilydwellingsand
serves both dwellings.
Clearances are in accordance
withlocal installationcodesand
the requirements of the gas
supplier.
M=Clearanceunder veranda,
porch, deck, or balcony 12 Inches (30 cm) permitted only if veranda, porch, deck,
orbalconyisfullyopenona
minimum of two sides.
Clearances are in accordance
withlocal installationcodesand
the requirements of the gas
supplier.
¹ In accordance with the currentCSA-B149.1 Natural Gas andPropane Installation Code
² In accordance with the current ANSI Z223.1 / NFPA 54 National Fuel Gas Code
Vent Terminal Air Supply Inlet Area where terminal is not permitted
FIGURE 1

Page 5
CLEARANCES
1. As you face the heater, the clearance to a side wall on the right side is 0” (Fig. 2), and the left side
is 1” (Fig. 2).
2. The minimum clearance from the top of the heater to the ceiling or any projecting overhang is
10”. (See Figure 2).
3. The minimum clearance from the bottom of the heater to the floor, or the top surface of carpeting,
tile, etc. is 0”. (See Figure 2).
4. When the appliance is installed directly on carpeting, tile or other combustible material other than
wood flooring, the appliance shall be installed on a metal or wood panel extending the full width
and depth of the appliance.
5. The minimum clearance from the edge of the vent cap to any overhanging obstruction, perpen-
dicular side wall, or corner of building is 12”. (See Figure 1).
6. Vent cap must be located at least 9” from any opening that would allow combustion products to
enter the building, windows, doors, etc., and 12” above the ground or shrubbery (See Figure 1).
Do not install vent cap in a window well. Provisions must be made to prevent snow accumula-
tion from infringing on vent cap clearances.
7. Clearances around vent cap must be maintained to assure adequate combustion and ventilation
air.
8. Clearances listed are minimum. Adequate accessibility clearances for servicing must be main-
tained.
0” FLOOR
0” FLOOR
HEDV40 HEDV25
10”
10”
CEILING OR OVERHANG CEILING OR OVERHANG
1”
1”
Left
Side
Wall
0”
Right
Side
Wall
0”
Right
Side
Wall
Left
Side
Wall
FIGURE 2
ATTENTION ALL CANADIAN CONTRACTORS/INSTALLERS: Before install-
ing this heater into a multi-family hi-rise exceeding four stories, contact the local build-
ing code inspector to verify the building construction complies with the Progressive
Collapse requirements as listed in the National Building Code of Canada 2005.

CLEARANCES
9. RESIDENTIALGARAGE INSTALLATION: Gas utilization equipment in residential garages
shall be installed so that all burners and burner ignition devices are located not less than 18 inches
(46 cm) above the floor. You must build a platform 18” above floor, the full width and depth of the
heater, including the rear trim kit. HEATER IS NOT DESIGNED TO HANG ON WALL.
Unit should be located or protected so it is not subject to damage by a moving vehicle. Use care in
selecting a good location within the garage. DO NOT locate the appliance where heated air will be
directed onto a nearby parked vehicle. Paint may discolor or rubber may harden and crack. DO
NOT allow open or closed containers of paint, gasoline or other liquids having flammable vapors to
be stored or used in the same area as the heater.
LOCATION
1. The wall furnace must be installed on an outside wall, unless optional Kit No. HEVK-5 is used.
2. For most efficient performance, locate furnace as centrally as possible in the area to be heated and
where occupants may move about freely without coming into contact with the cabinet, and within
reach of a 115V wall outlet.
3. If the furnace is installed in a basement, a 12” clearance must be maintained between ground
level and the bottom of the vent cap. Do not install furnace where vent cap will terminate in a
window well or any other opening below ground level. (See Figure 3). Do not allow snow
accumulation to build up within 12” of the vent cap.
OPTIONALKITS
1. HEVK-5 - To extend vent 5 foot from heater. This will allow vent cap to be installed above
grade from basement or to an outside wall. Atotal of 3 kits with 2 additional elbows may be
used.
Page 6
12” Minimum above grade
without excavation
FIGURE 3

INSTALLATION
Failure to follow these instructions carefully could result in poor performance, property damage, personal injury,
or death.
STEP 1. LOCATE VENT OPENING (Requires 3-1/2” diameter wall opening)
a) Select area on wall where heater will be installed. Using template (packed with heater) mark shaded area
where hole can be cut and to locate the wall brackets. (See Figure 4).
b) Locate studs on each side of this area.
c) Mark location for 3-1/2” diameter hole between studs. Hole should be offset to miss studs. (See Fig. 4).
d) Check outside wall at this location for proper clearances around vent cap. (See Fig. 1).
e) Cut vent openings into both the inside and outside walls, being sure to maintain level across both open-
ings.
STEP 2. ROUGH-IN GAS SUPPLY (See Figure 5)
Install at least 3/8” gas supply line. Contact local gas supplier if any questions.
Install a drip leg in gas supply line immediately upstream from the gas connection to heater (see local
codes), and provide a 1/8” N.P.T. plugged tapping, accessible for test gauge connection and an indi-
vidual manual shut off valve accessible within room where heater is installed. (See Figure 5). The
heater and its individual shut off 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 psig (3.5Pa). The heater must be
isolated from the gas supply piping system by closing its individual manual shut off valve during any
pressure testing of the gas supply piping system at test pressures equal to or less than 1/2 psig (3.5Pa).
Test all connections for leaks using a soapy solution. NEVER USE AN OPEN FLAME TO TEST FOR
LEAKS.
The maximum inlet gas supply pressure for Natural or L.P./Propane gas is 1/2 p.s.i. or 14” w.c.
The minimum inlet gas supply pressure for the purpose of adjustment is 4.5” w.c. for Natural gas or 11.0” w.c. for
L.P./Propane gas. Page 7
FIGURE 5
Gas Valve
Back of
heater
Wall
Gas Supply Drip
Leg
Manual shut-off valve
must be accessible in
room where heater is
installed
Manual shut off valve with
1/8” NPT plugged tapping
Must be accessible in room
where heater is installed
3/8” Black iron pipe
Template
Shaded
Area
Wall
Studs
16” O.C.
FIGURE 4
ATTENTION ALL CANADIAN CONTRACTORS/INSTALLERS: Before installing
this heater into a multi-family hi-rise exceeding four stories, contact the local building
code inspector to verify the building construction complies with the Progressive Col-
lapse requirements as listed in the National Building Code of Canada 2005.

INSTALLATION - CONTINUED
STEP 3 INSTALLING VENT SYSTEM 5” - 32” WALLTHICKNESS (12.7 cm - 81.3 cm)
a) Use only factory supplied parts. Do not attempt to modify in any way. To do so could cause a system
imbalance resulting in poor performance and/or unsafe operating conditions.
b) Slide collection box pipes through cutout and secure collection box to inside wall. Anchors (not sup-
plied)
may be required. (See Figure 5).
c) From outside house, mark collection box pipes and cut off 1/2” beyond outside wall.
d) Slide vent cap pipes onto collection box pipes and push in until flange is flush against house. Secure vent
cap assembly to outside wall with a slight downward slope. This will prevent water from entering and
allow condensation to drain. Caulk around the edges of the vent cap mounting plate. NOTE: It may
be necessary to build a metal or wood frame to provide a flat surface for the mounting plate to be flush
against or to attain the 5” minimum wall thickness.
Page 8
FIGURE 5
6-1/4”
(15.9 cm)
Trim Kit Brackets
Gas Inlet
Air Intake
Flue Outlet
6-1/8”
(15.6 cm)
4-1/8”
(10.2 cm)
25”
(63.5 cm)
20-11/16”
(52.5 cm)
7-9/16”
(19.2 cm)
HEDV40 - Figure 6
6-3/8”
(16.2 cm)
4”
(10.2 cm)
29-5/8”
(75.2 cm)
25-1/16”
(63.7 cm)
7-9/16”
(19.2 cm)
5-7/8”
(14.9 cm)
Trim Kit Brackets
Gas Inlet
Air Intake
Flue Outlet
HEDV25 - Figure 6
Collection Box
Assembly
Vent Cap
Assembly
Vent Cap
Mounting
Plate
FIGURE 7 FIGURE 8

Page 9
STEP 4. INSTALLING HEATER
a) Locate (and mark) wall mounting bracket location on wall using template supplied.
b) Secure wall brackets to wall, anchors (not provided) may be required.
c) Secure trim kit brackets to back of heater using eight #8 screws provided. (See Figure 9).
d) Slide heater to approximately 5” of wall.
e) Secure air intake hose to back of heater and the collector box assembly using hose clamps provided. (See
Figure 8).
f) Secure vent exhaust tube to exhaust tube on back of heater and the exhaust tube on the collection box
assembly using hose clamps provided. (See Figure 8).
g) Connect 3/8” minimum gas supply line to manual cut-off valve on back of the heater. (See Figure 5).
h) Locate factory installed thermostat wires extending from rear of the heater. Connect 24 V. thermostat
wall thermostat (provided) using a maximum 20’ of thermostat wire. Do NOT splice thermostat wire.
i) Secure right and left trim side panels to the wall and trim kit brackets with eight #8 screws provided.
(See Figure 9). This will space the back of the heater 5” from the wall.
j) Secure trim top to trim sides using four #8 screws provided.
k) Plug three-pronged factory wired power cord into a properly grounded 115 Volt electrical outlet. NEVER
use an extension cord. If homeowner desires, heater can be hard wired by a licensed electrician. See
local electrical codes.
l) Turn the manual gas control valve on. Check all connections for leaks using a soapy solution. NEVER
check for leaks with an open flame.
HEATER IS NOW INSTALLED, FOLLOW LIGHTING INSTRUCTIONS TO PLACE HEATER INTO SER-
VICE. FRONT PANEL MUST BE REMOVED FOR ACCESS TO LIGHTING INSTRUCTIONS AND GAS
CONTROL.
FIGURE 9
Trim Kit Top
1/2”
Bushing
Trim Kit
Left Side
Trim Kit
Bracket (4)
Trim Kit
Right Side

OPERATING INSTRUCTIONS
TO TURN OFF GAS TO APPLIANCE
1. Set the thermostat to lowest setting.
2. Turn off all electric power to the appliance if service is to be performed.
3. Turn gas control knob clockwise to “OFF”. Do not force.
A. This appliance does not have a pilot. It is - If you cannot reach your gas supplier, call
equipped with an ignition device which the fire department.
automatically lights the burner. Do not try
to light the burner by hand. C. Use only your hand to push in or turn the gas
control knob. Never use tools. If the knob will
B. BEFORE OPERATING smell all around the not push in or turn by hand, don’t try to repair
appliance area for gas. Be sure to smell next it, call a qualified service technician. Force or
to the floor because some gas is heavier than attempted repair may result in a fire or explosion.
air and will settle on the floor.
WHAT TO DO IF YOU SMELL GAS: D. Do not use this appliance if any part has been
- Do not try to light any appliance. under water. Immediately call a qualified service
- Do not touch any electric switch; do not technician to inspect the appliance and to
use any phone in your building. replace any part of the control system and any
- Immediately call your gas supplier from a gas control which has been under water.
neighbor’s phone. Follow the gas supplier’s
instructions.
FOR YOUR SAFETY READ BEFORE OPERATING
WARNING: If you do not follow these instructions exactly, a fire or explosion may result
causing property damage, personal injury or loss of life.
Gas control knob shown
in “OFF” position
1. STOP! Read safety information on this label. 7. Wait five (5) minutes to clear out any gas. If
2. Set the thermostat to the lowest setting. you smell gas, STOP! Follow “B” in safety
3. Turn off all electric power to the appliance. information on this label. If you don’t smell
4.. This appliance is equipped with an ignition device gas, go to next step.
which automatically lights the burner. Do not try 8. Turn gas control knob counterclockwise
to light the burner by hand. to “ON”.
5. Remove cabinet to access gas control knob. 9. Turn on all electric power to the appliance.
6. Turn gas control knob clockwise to 10. Set thermostat to desired setting.
“off”. Do not force. 11. If the appliance does not operate, follow
instructions “To Turn Off Gas To Appliance”
and call your service technician or gas
supplier.
12. Replace cabinet.
Page 10

Page 11
NOTE: THE FURNACE AND ALL COMPO-
NENTS MUST BE INSPECTED AT LEAST
ANNUALLY BY A QUALIFIED SERVICE
TECHNICIAN. THISSHOULDINCLUDETHE
BURNER, HEAT EXCHANGER, AND VENT
SYSTEM. BE SURE THAT THE FLOW OF
COMBUSTIONAND VENTILATIONAIRARE
NOT OBSTRUCTED AND THAT ALL HOSES
ARE UNDAMAGED,ANDALLCLAMPSARE
SECURELY TIGHTENTED.
Primary Flame
Burner
Secondary Flame
Heat Exchanger Tube
FIGURE 10
FIGURE 11
Burner
Box Top
Manifold
Burner
Burner
Bracket
Direct Spark Ignitor
Maxitrol
Gas Valve
MODEL 0 to 2,000’ 4,000’ 6,000’ 8,000’ -
NO. 2,000’ 4,000’ 6,000’ 8,000’ 10,000’
NATURALGAS
HEDV253A 51 52 52 53 54
HEDV403A 45 47 48 49 50
L.P. GAS
HEDV254A 58 60 62 63 64
HEDV404A 55 55 56 56 57
PROPER BURNER FLAME
The burner flame may be observed by raising the sight
glass cover. A proper flame will have a dark blue inner
mantle, with a lighter blue outer mantle that extends from
the burner into the heat exchanger tube, (see Figure 10).
Thereisnoprimaryair adjustmenton theburner, andproper
flame is assured since the correct manifold pressure and
orificing have been done at the factory.
TO REMOVE MAIN BURNER FOR
INSPECTIONAND CLEANING
1. Turn off all electrical supply to heater.
2. Turn off gas supply.
3. Remove front panel.
4. Unplug wire to direct spark ignitor and sensor.
(See Fig. 11.)
5. Disconnect vacuum hose from burner box.
6. Remove screws holding burner box top to
burner box. (See Figure 11.)
7. Remove burner plate and burner box top. Take
care not to contact, or strain ignitor in any way
as it is extremely fragile. (See Figure 11.)
8. Remove 2 nuts holding burner bracket. (See
Figure 11).
9. Slide burners toward heat exchanger and lift up
from rear and back. (See Figure 11).
10. Clean or replace as needed.
11. Reinstall by reversing Steps 9 - 1.
BURNER ORIFICE
This appliance equipped only for altitudes 0 - 2,000 ft.
Appliance input ratings are based on sea level operation
and need not be changed for operation up to 2,000 feet
(609.9 m) elevation. For operation at elevations above
2,000 feet (609.9 m).
The BTU input must be reduced 4% per 1,000 ft. Orifice
change must be completed by a qualified installer or ser-
vice technician. See the following orifice chart for the
proper orifice drill size for a specific elevation.
SPECIFIC ELEVATIONS

WIRING
This appliance is equipped with a three prong power cord
with grounding plug. For your protection against shock
hazard, this appliance should be plugged directly into a
properly grounded three-prong receptacle. Do not cut or
remove the grounding prong from this plug.
NOTE: If any of the original wire supplied with this
appliance has to be replaced, it must be replaced with
type 105ºC wire or its equivalent.
CAUTION: Label all wires prior to disconnection when
servicing controls. Wiring errors can cause improper and
dangerous operation.
Verify proper operation after servicing.
WARNING
THIS IS A GAS-FIRED APPLIANCE. KEEP THE
AREA CLEAR OF GASOLINE AND OTHER FLAM-
MABLE VAPORS AND LIQUIDS. ALL COMBUS-
TIBLE MATERIALMUST BE KEPTCLEAR OF THIS
AREATOAVOID FIRE OR EXPLOSION.
Page 12
Ground Brown 24 VAC
HEDV25-A,
HEDV40-A
PICTORIAL
Thermostat
Purple
Red
White
Black
Black
Orange Red
Black
Black
R G W C
Pressure
Switch
Gas
Valve
Draft
Inducer
Circulating
Blower
Limit
Switch
Yellow
24 V
CMB Blower
Circuit
Board
Transformer
Black
ACC
AC8 COOL
L1
Blue
24
VAC
Green
HEDV25-A,
HEDV40-A
LADDER
Gas Valve
Pressure
Switch
Limit Switch
Thermostat
CIRCUIT BOARD
115 VAC
Draft Inducer
Circulating
Blower
HEDV253A, HEDV254A, HEDV403A, & HEDV404A
WIRING DIAGRAM

Page 13

Pressure switch
closes proving
inducer
Heater
in
stand-
by
Thermostat
calls for
heat
Power
on to
draft
inducer
Pressure
switch
closes
inducer
proved
Spark
ignition
energized
Gas
valve
opens
gas
flow to
burner
Burner
flame
proved
Blower
on Heat
cycle Thermostat
satisfied




Gas
valve
closes
gas flow
to burners
off
Draft
inducer
off
Blower
off
Heater
in
stand-
by

Inducer
continues to
run

One Hour
Lock Out

15 Sec.
inter
purge
3 Attempts
for ignition




30 Sec. 180 Sec.
90 Sec.
4 Sec.
NO
NO
YES
YES
NO
NO
YES
YES
STEP # 1) Thermostat calls for heat. 2) Draft Inducer turns on. 3) Pressure switch closes. 4) Spark ignition begins. 5) Gas flow to burner. 6) Burner ignition proven. 7) Circulating Blower on. 8) Heater burns through heating cycle. 9) Thermostat satisfied. 10) Gas flow off to burner. 11) Draft inducer off. 12) Circulating Blowers off. 13) Heater in stand-by. NOTE: IF THERE ISA MALFUNCTION IN STEPS 3, 5, 6 THE OPERATION SEQUENCE WILL STOPAT THAT POINT. FOR STEPS 5 OR 6, IF AFTER 2 ADDITIONALATTEMPTS MALFUNCTION STILL OCCURS, THE CONTROL WILL LOCK OUT FOR ONE HOUR. FOR PURPOSE OF TESTING, THE ONE HOUR LOCKOUT CAN BE OVERRIDDEN BY RESETTING THE THERMOSTAT OR INTERRUPTING THE ELECTRICAL POWER.
HEDV SEQUENCE OF OPERATION

P/N 72612
2”x6’ Black
Flex Tubing P/N 72532
Use only if connecting
flex tubing of 2 or
more ktis
P/N 72575 2”x5’
Black Flocked Tube P/N 72593
2” Hose Clamps
P/N 41515
Support
Brackets (2)
P/N 72578 2”x3”
Black Silicone
Wrapped Coupling
P/N 41520
Center Bracket
HEVK-5 5’VENT EXHAUST KIT
INSTALLATION INSTRUCTIONS
WARNING: Use only Louisville Tin & Stove Company factory supplied parts and kits. Failure to do so could result in loss
of life, personal injury, property damage, or unsatisfactory performance. This kit must be installed by a qualified installer or
service technician. CONTENTS OF KIT
1 only P/N 72532 2”x3” Steel Coupling 1 only P/N 41520 Center Bracket
1 only P/N 72575 2”x5’ Black Flocked Tube 8 only P/N 72593 2” Hose Clamps
1 only P/N 72612 2”x6’ Black Flex Tubing 1 only P/N 72578 2”x3” Black Silicone
2 only P/N 41515 Support Brackets Wrapped Coupling
STEP 1 - LOCATE VENT OPENING
a) Select location on outside wall that vent will exit through.
b) Check outside for proper clearances around vent cap. See installation instructions.
c) Mark and cut 3-1/2” hole through both inside and outside walls, being sure to maintain level across both openings.
d) Measure wall thickness. Mark and cut off both intake and exhaust pipes to 1/2” beyond outside wall.
e) Secure collection box to wall. Wall anchors, not provided, may be required.
STEP 2 - INSTALL HEATER
a) Select location on wall where heater will be installed.
b) Using wall template supplied with heater, mark location for trim kit wall brackets.
c) Attach brackets to wall (wall anchors, not provided may be required) and back of heater. Using screws provided on
back of heater.
d) Slide heater into position and secure brackets togehter. This should position back of heater 5” off wall.
e) Select direction vent will exit trim kit, left, right, or straight up.
f) Before installing trim kit remove knockout on this side.
STEP 3 - INSTALL VENT
a) Remove and discard P/N 72611 2”x24” black flex tubing from air inlet. (Save hose clamp).
b) Attach P/N 72612 2”x6’ black flex tubing to air inlet. Secure with P/N 72593 2” hose clamp.
c) Slide P/N 72575 2”x5’ flocked tube through trim kit opening (knockout) and attach to P/N 72610 orange silicone
90E elbow supplied with heater. Secure with 2” hose clamp.
d) Attach P/N 41515 support brackets to wall. Wall anchors, not provided, may be required. Postion support brackets
within 8” from side of trim kit and end of pipe. Secure flex tubing and flocked tube to brackets using 2” hose
clamps.
e) Attach P/N 41520 center bracket 2-1/2’ from pipe end and insert flex tube through bracket. This will prevent the
flex tube from touching the black flocked exhaust tube.
f) Connect flex air intake tube and flocked exhaust tube to collection box.
g) Complete gas connection and attach trim kit to brackets.
h) Follow lighting instructions.
SPECIAL NOTES
a) You may use up to three HEVK-5 Kits for a total of 15’vent extension with two additional elbows. DO NOT
EXTEND VENT BEYOND 15’OR USE MORE THAN THREE TOTAL ELBOWS (one elbow comes with the
heater).
b) To connect two vent kits together use P/N 72532 2”x3” steel coupling. Secure with 2” hose clamps.
c) If you are using one, two, or three kits, after installation is complete you will discard 2 P/N 72593 hose clamps and
one P/N 72532 steel coupling.
d) If you need to make a 90E offset you will need to order P/N HEEL-1 90E Elbow Kit. Two offsets require two kits.
e) If complete vent extension is horizontal, pipes may be sloped down slightly to allow any condensate to
drain through the exhaust pipe to the outside. DO NOT ALLOW TO DRAIN ONTO WALKWAY. If any part of
vent extension is vertical or local codes do not allow draining of condensate to outside you must add P/N 18900
Condensate Kit.
f) For cosmetic purposes, the addition of the HEVK-5 Kit can be enclosed by adding a HEVE-5 Vent Enclosure Kit.
To completely enclose the HEVK-5 Kit one HEVE-5 will be needed for each HEVK-5 used.
Page 14

HEVE-5
VENT ENCLOSURE KIT
INSTALLATION INSTRUCTIONS
This kit must be installed by a qualified installer or
service technician.
STEP 1) Position end of Part No. 41610 enclosure body to
heater trim kit where pipes exit trim kit, centering
pipes inside body and attach to wall. Wall anchors,
not provided, may be required. Collector box may
be behind HEVE-5 Kit.
STEP 2) Cut to fit enclosure panel 1” beyond end of vent
run. Insert Part No. 41620 End Cap and attach
using three #8 screws provided.
SPECIAL INSTRUCTIONS
STEP 3) If more than one HEVE-5 Kit is used, attach Part
No. 72604 Trim Kit where ends meet.
STEP 4) If making a 90º turn, measure 1” beyond outside
turn and cut off enclosure panel. Notch panel on
surface of direction turn is being made to allow
pipes to pass through into next HEVE-5 Kit.
Attach second panel to wall and attach Part No.
72604 Trim Kit where two bodies meet. Install
end cap Part No. 41620.
Page 15
HEEL-1
90ºELBOW KIT
Contains 1 only P/N 72613 90º Elbow 2”

Page 16
72618 -
Condensate Trap
80190 - Casing
Black Plug
Inducer
Drain Cap
72538 -
Flex
Hose
72539 - Hose
Clamp (2)
50606 - #8x12 Screw
(2)
FIGURE 2
Weld
Pin (2)
Condensate Pan
Assembly
Wing Nuts (2)
FIGURE 1
18900 CONDENSATE KIT
INSTRUCTIONS
HI-EFFICIENT DIRECT-VENT WALL FURNACE
Always use this kit when the vent has a vertical run, or where local codes prohibit draining condensate to the outside. Use
only Cozy Heating Systems supplied parts. Failure to use factory supplied parts or to follow these instructions may result
in unsatisfactory performance, property damage, personal injury and/or loss of life.
Before beginning kit installation, open carton and identify the following components.
A) P/N 18910 Condensate Pan Assembly
B) P/N 72618 Condensate Trap Assembly
C) P/N 72538 3/8” Tubing
D) P/N 72539 3/8” Hose Clamp (2)
E) P/N 50606 #8 x ½” screws (2)
Step 1. Set thermostat to “off” and allow heater to cool.
Step 2. Turn off gas supply to heater.
Step 3. Turn off electric power to heater.
Step 4. Remove the cabinet.
Step 5. Loosen the two wing nuts located in the heater base. See Figure 1.
Step 6. Slide the condensate pan into the bottom of the heater with slots in tabs onto the weld studs and under the wing
nuts. Use care to not rip the insulation in bottom of heater. Tighten the wing nuts to secure condensate pan.
See Figure 1.
Step 7. Remove and discard the button plug located at center lower area of heater back.
Step 8. Attach condensate trap to heater back so bottom of trap is inside the bottom of the condensate pan. Secure
using the (2) #8 screws provided. Fill trap with water. See Figure 2.
Step 9. Remove and discard plastic cap from bottom of the draft inducer drain tube. See Figure 2.
Step 10. Connect the tubing to the draft inducer drain tube and the condensate trap. Secure both ends with two 3/8”
hose clamps provided. See Figure 2.
Step 11. Fill the condensate pan with water.
Step 12. Reverse steps 4 – 1. Follow lighting instructions to place heater in operation.
WARNING: The water level in the condensate pan must be checked and maintained to completely cover the condensate
trap. The water provides a seal to prevent combustion products from coming through the condensate trap and entering the
living area.
Form No. 72936

MAINTENANCE INSTRUCTIONS
For proper and safe operation keep furnace and furnace area clean. At regular intervals turn control valve to off, let
cool and clean inside control and heat exchanger compartment. To clean front panel use only a damp cloth, do not
use any kind of solvent or cleaning fluid that could leave a residue to burn or give off fumes when furnace is
turned on.
Have the furnace checked, cleaned, and repaired by a qualified service technician. Check venting system, and
burner operation prior to use each year.
Follow a regular service and maintenance schedule for safe and efficient operation.
Do not obstruct combustion and ventilation air. Examine the venting system as a routine part of the safety perfor-
mance check on an annual basis.
If the heat exchanger is removed, check the heat exchanger intake gasket and draft inducer gasket and replace if there
is any sign of damage. Be sure all gaskets are in place when the heat exchanger is replaced.
Failure to replace any gasket that has been damaged may result in property damage, personal injury or loss of life.
Oil the bearings of the fan motor every 6 months with S.A.E. 20 oil.
SERVICE RECORD
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Page 17

TROUBLE SHOOTING CHART - For use by a qualified service technician.
Page 18
CORRECTIVE ACTION
SYMPTOM POSSIBLE CAUSES To be taken by Contractor
Flame too large 1. Defective operator section of valve. 1. Replace valve.
2. Burner orifice too large. 2. Check with local gas company for proper
orifice - size and replace.
3. If installed above 2,000 ft. 3. See burner orifice section, Page 11.
Yellow burner flame 1. Clogged burner ports. 1. Remove burners and check for obstruc-
tions in throats, ports, and orifices. Clean -
but do not enlarge ports or orifices.
2. Obstruction around vent cap. 2. Make sure area around vent cap is clear, be
sure vent system is sealed.
Gas odor 1. Gas leak. 1. See Page 1.
Delayed Ignition 1. Low gas pressure. 1. Check gas supply pressure.
2. Igniter not properly located. 2. Check ignitor location and correct if
necessary.
Failure to ignite 1. Main gas off. 1. Open manual gas valve.
2. Thermostat not set high enough to call 2. Set thermostat to higher temperature.
for heat.
3. Clogged burner orifice. 3. Clean burner orifices (do not enlarge).
4. Incorrect wiring. 4. Check wiring diagram.
5. Defective valve. 5. Replace valve.
6. No power to unit. 6. Plug in power supply cord. Check 115 V.
wall outlet.
Burner won’t 1. Defective or damaged thermostat wire, 1. Can be checked by removing wire from con-
turn off or thermostat. trol board terminal. If burner goes off, replace
thermostat.
2. Thermostat location. 2.Re-locate out of drafts, hot, or cold spots.
3. Defective or sticking valve. 3. Replace valve.
4. Excessive gas pressure. 4. Contact utility supplying gas.
5. Defective or damaged thermostat. 5. Replace thermostat.
Incorrect gas 1. Gas input not checked. 1. Re-check gas input.
input 2. Clogged orifices. 2. Clean orifices with a smooth wood toothpick,
do not enlarge.
Not enough heat 1. Furnace undersized. 1. This is especially true when a dwelling or
room is enlarged. Have the heat loss
calculated and compare to furnace output.
Your gas company can supply you with this
information. If furnace is undersized,
replace with correct size unit.
2. Thermostat temperature set too low. 2. Raise thermostat temperature setting.
3. Incorrect supply pressure. 3. Check supply pressure.
Too much heat 1. Temperature set too high. 1. Lower temperature setting.
2. Combination control valve stuck open. 2. Replace combination control valve.
Main burner 1. Defective flame sensor. 1. Check voltage and replace if low.
goes out 2. Input too high. 2. Check input rate.
during normal 3. Sight glass not air tight. 3. Tighten screws securing sight glass. Check
operation and replace gasket if needed.
4. Vent tubes not properly installed or 4. Follow instructions. Check both exhaust and
sealed. air intake tubes, and vent cap. Be sure all
gaskets are in place and properly sealed. Use
only tubes and vent cap supplied. Do not
alter vent tubes or cap.
5. Limit switch opens. 5. Check for blockage of discharge air.
6. Exhaust or Air Intake tubes blocked. 6. Check for and remove any obstruction to
incoming circulating air.

# OF REASON FOR CORRECTIVE ACTION
FLASHES INDICATION POSSIBLE CAUSES TO BE TAKEN BY CONTRACTOR
Slow Flash Normal operation,
no call for heat
Fast Flash Normal operation,
call for heat
2 System lockout a.) Defective ignitor. a.) Replace ignitor.
failed to detect or b.) Ignitor cable defective. b.) Replace ignitor cable.
sustain flame c.) Ignitor cable disconnected. c.) Connect ignitor cable.
d.) Manual gas valve in “OFF” d.) Turn manual gas valve to “ON”.
position. No gas to valve.
e.) Defective wire to gas valve. e.) Replace defective wire.
f.) Wire to gas valve disconnected. f.) Connect gas valve wire.
g.) Obstruction to vent outlet. g.) Remove obstruction.
h.) Obstruction to air inlet. h.) Remove obstruction.
3 Pressure switch a.) Defective pressure switch. a.) Replace pressure switch.
Open or Closed b.) Pressure switch tubing b.) Replace damaged tubing.
damaged, kinked or collapsed.
c.) Pressure switch tubing c.) Connect pressure switch tubing.
disconnected.
d.) Defective draft inducer. d.) Replace draft inducer.
e.) Pressure switch tubing to e.) Reverse tubing connections on
wrong connection. pressure switch.
4 Limit Switch opens a.) Defective limit switch. a.) Replace limit switch.
b.) Damaged limit switch wire. b.) Replace damaged wire.
c.) Limit switch wire c.) Connect limit switch wire.
disconnected.
d.) Blockage in front of front d.) Remove blockage.
panel.
e.) Heater over rate. e.) Check orifice, pressures, rate.
5 Flame sensed gas a.) Defective gas valve. a.) Replace gas valve.
valve not energized b.) Defective control module. b.) Replace control module.
Steady light Internal failure a.) Defective control module. a.) Replace control module.
No Flashes (control module
failure and power
on self-check)
TROUBLE SHOOTING CHART- for use by a qualified service technician.
To assist in diagnosing and servicing, this heater is equipped with a self-diagnosing
control module. Should a malfunction occur, the green indicator light on the control
module will flash a varying number of times indicating the circuit in which malfunction
is located.
Page 19

HI-EFFICIENT DIRECT VENT
WALL FURNACE
Prices and specifications subject
to change without notice.
All prices are F.O.B. factory.
Page 20
MODEL NUMBERS
HEDV253A - NAT. GAS
HEDV403A - NAT. GAS
HEDV254A - L.P. GAS
HEDV404A - L.P. GAS
ATTN: CONTRACTORS AND SERVICE TECHNICIANS, we only sell parts through our wholesalers, but the prices
listed are for your convenience. For prompt parts service, contact the wholesaler from which you purchased your Cozy
heater. NOTE: Parts & schematic drawings on current models are shown at www.cozyheaters.com.
Rev. 05/2012
44
40
3
2
42
29
1
4
45
30
31
32
33
35
39
38 41 23
22 43
36
37
28
24
21
20 15
14
1719
18
16
12 13
11
810
27
7
6
9
526
25
47
46
34