Lennox DT3025, DTH3025, DR3025, DRH3025, DT3530 Installation Instructions Manual

E

2001 LennoxIndustries Inc.

Dallas, Texas



INSTALLATION
INSTRUCTIONS

DT/DTH/DR/DRH

DR4035 FLUSH-FACED MODEL SHOWN

This appliance may be installed in an aftermarket
permanentlylocated,manufactured(mobile)home,
wherenotprohibited bylocalcodes.Thisappliance
is onlyfor use withthe type ofgas indicated onthe
rating plate. This appliance is not convertible for
use with othergases, unless a certifiedkit is used.

RETAIN THESE INSTRUCTIONS

FOR FUTURE REFERENCE

MERITt

DIRECT VENT
VENTED GAS FIREPLACE/
VENTED GAS FIREPLACE HEATER
850,010M
05/2001
Supersedes 504,023M 11/99

Series

Litho USA

Table of Contents

DT/DTH/DR/DRH Unit Dimensions 2..................

MerittSeries DT/DTH/DR/DRH 2....................

Shipping and Packing List 3..........................

Requirements 3....................................

General 3.........................................

Combustion Air 4...................................

Location Selection 4................................

Installation Clearances 5............................

Framing 6.........................................

Installation 6......................................

Venting 12.........................................

Gas Piping 21......................................

Unit Start-up 21....................................

Adjustments 23.....................................

Service 24.........................................

Wiring Diagram - Millivolt Gas Valves 24...............

Wiring Diagram - Electronic Gas Valves 25.............

Repair Parts List 25.................................

Venting Kits & Available Components 26...............

WH Report No. J20046561

FORYOURSAFETY

Do not store or use gasoline or other
flammable vapors and liquids in the
vicinity of this or any other appliance.

Installation and service must be
performed by a qualified installer,
service agency or the gas supplier.

WARNING

If the information in this manual is not
followed exactly, a fire or explosion
may result causing property damage,
personal injury or loss of life.

WHAT TO DO IF YOU SMELL GAS:

Do not try to light any appliance.
Extinguish any open flames.
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.

Page 1

DT/DTH/DR/DRH Unit Dimensions - inches (mm)

D

D

D

D

D

FRAMING
SPACERS

(Top and Sides

and Rear)

A

G

7 (178)

(Louvered Front Model Shown)

COMBUSTION AIR - 7-1/2 (190)

*CONCENTRIC FLUE

FLUE - 4-1/2 (114)

* DT/DTH - top flue only

DR/DRH - rear flue only

TOP VIEW

NOTE - Eyebrow

hood shown as positioned

in louvered front model.

ELECTRICAL

INLET

2-3/4x2 (70x51)

COVER PLATE with

KNOCKOUT)

C

GAS INLET
(Either Side
and bottom)

3 (76)

2 (51)

B

3 (76)

E

D

FRONT VIEW

Model No. A B C D E **F G

T/DR3025

T/DR3025

DTH/DRH3025

DT/DR3530

T/DR3530

DTH/DRH3530

DT/DR4035

T/DR4035

DTH/DRH4035

T/DR4540

in. 19-7/8 30-1/8 30-1/8 24-1/2 14
mm 505 765 765 616 356
in. 24-7/8 35-1/8 32-1/8 29-1/2 16
mm 632 892 816 749 406
in. 29-7/8 40-1/8 37-1/8 34-1/2 21
mm 759 1019 943 876 533
in. 34-7/8 45-1/8 37-1/8 39-1/2 21
mm 886 1146 943 1003 533

16

(406)

9-3/4
(248)

RIGHT SIDE VIEW

**DR/DRH -rear flue only

1/2 (13)

2 (51)

1-5/8

(42)

18-1/4

464

20-1/4

514

25-1/4

641

25-1/4

641

FIGURE 1

Meritt Series - DT/DTH/DR/DRH

MerittSeries fireplaces are sealed-combustion (direct
vent), heat-circulating gas appliances. The appliances
utilizea100 percentsafetyshut-offgas controlwitheither
a Piezo ignition system or an electronic ignition system.
Models equipped with either electronic ignition or the op­tionalforcedair fanassemblyrequire 120Velectricalcon­nection. Decorative trim kits, a brickaded firebox lining,
forced air fan assemblies, a wall thermostat (for usewith
vented gas fireplace heater models only), and hand-held
remote ON/OFF controls are available as options. Refer
to table 1 for model designations.

Thefireplacehas provisionsforside(s) orbottomentryfor
gas piping. This appliance must be vented to the outside
andmustnot be connectedtoa flueservicinganotherap­pliance.

The appliance must be installed using only approved Lennox
concentric venting components (4-1/2 in. / 7-1/2 in.).

Themillivolt gasvalveused innon-electronicigni­tion units is self-powered and does not require
120V power wiring.

Do not attempt to alter or modify the construction of the
appliance or venting components. Any modification or al­teration ofconstructionwillvoid the warranty,certification
and approval of these units.

In vented gas fireplace heater models, burner operation
can be controlled by: a unit- or wall-mounted ON / OFF
switch, or an approved thermostat.
In vented gas fireplace models, burner operation can be
controlled by: a unit- or wall-mounted ON / OFF switch.
On modelswiththeoptional manually-modulated gas valve,
flame appearance and heat output can be controlled at the
gas valve.

TABLE 1

Models Listed
to Vented Gas

Fireplace

Standard

DT/DR3025
DT/DR3530
DT/DR4035
DT/DR4540

*DRH/DTH models available with louver front only.

Models Listed to

Vented Gas

Fireplace Heater

Standard

DTH/DRH3025
DTH/DRH3530
DTH/DRH4035

Suffixes Used with

C - Louver front
F - Flush-Faced Front*
N-NaturalGas
P - Propane Gas (LP)
M - Millivolt System
E - Electronic system

F**

9-15/16

252

12-7/16

316

14-15/16

379

17-7/16

443

Both Models

Page 2

Shipping and Packing List

Package 1 of 1 contains:

1 - Assembledventedfireplace /vented fireplaceheater

(includes log set, rock wool)

1 - Envelope containing installation instructions, user’s

manual,warranty,surveycard;and with theDT/DTH
models, also a vent restrictor

1 - Eyebrow

Check for shipping damage. The receiving party should con­tact last carrier immediately if any shipping damage is found.
All venting components are ordered and shipped separately.

Requirements

Lennox MerittSeries vented gasfireplaces/vented gas
fireplace heaters are Warnock Hersey certified to ANSI
Z21.88b-1999 inUSA(In Canada, CSA-2.33b-M99), and
CAN/CGA-2.17-M91 in both USA and Canada.

Installation of Lennox gas appliances must conform with lo­cal buildingcodes.Inthe absence of local codes, unitsmust
be installed according to the current National Fuel Gas
Code(ANSI-Z223.1)inthe United St ates.The National Fuel
Gas Code is available from:

American National Standards Institute, Inc.
11 West 42nd Street
New York, NY 10036

In Canada,installationmust conform with current Nation­al Standard of Canada CAN/CGA-B149.1 “Installation
Code for Natural Gas Burning Appliances and Equip­ment” and CAN/CGA-B149.2 “Installation Code for Pro­pane Gas Burning Appliances and Equipment” and other
applicable local codes.

This appliance is Warnock Hersey certified for installation
clearances to combustible material as listed on appliance
rating plate and in table 2. Accessibility and service clear­ances must take precedence over fire protection clear­ances.

TABLE 2 - CLEARANCES TO COMBUSTIBLES

BACK 1/2 in. (13 mm); 0 in. (0 mm) spacers

SIDES 1/2 in. (13 mm); 0 in. (0 mm) spacers

TOP SPACERS 0 in.(0 mm)

FLOOR 0 in. (0 mm)

VENT 1 in. (25.4 mm)*

SERVICE CLEARANCES

FRONT 3 FeeT. (0.9 meters)

* 3 in. (75mm) above any horizontal vent component.
NOTE - For installation on combustible floors, appliance shall

not be installed directly on carpeting, tile, or other combus­tible material other than wood flooring.

Fireplace must be installed so thatelectrical components
(if applicable) are protected from water.

When120volt power isinstalled,appliance must beelec­trically grounded in accordance withlocalcodes.Inaddi­tion, in the United States, installation must conform with
the current National Electric Code, ANSI/NFPA No. 70.
The National Electric Code (ANSI/NFPANo. 70) is avail­able from:

National Fire Protection Association
1BatteryMarchPark
Quincy, MA 02269

In Canada, all electrical wiring and grounding for the unit
must beaccordingtothe current regulations of the Cana­dian Electrical Code Part I (C.S.A. Standard C22.1) and/
or local codes.

Field wiring connection with unit must meet or exceed
specifications of type T wire and withstand a maximum

°

temperature rise of 180
These units have been Warnock Hersey certified for

installation in bedrooms and mobile homes.

F(82°C) .

General

These instructions are intended as a general guide and do
not supersede local codes in any way. Consult authorities
having jurisdiction before installation.

WARNING

Product contains fiberglass wool.
Disturbing the insulation in this product during

installation,maintenance, or repairwill expose you
to fiberglass wool. Breathing this may cause lung
cancer. (Fiberglass wool is known to the State of
California to cause cancer.)

Fiberglass wool may also cause respiratory, skin,
and eye irritation.

To reduce exposureto this substanceor for further
information, consult material safety data sheets
available from address shown below, or contact
your supervisor.

Lennox Industries Inc.
P.O. Box 799900
Dallas, TX 75379-9900 USA

1 - This appliance is certified for use with the factory-sup-

plied glass panel only. Do not operate the appliance if
the glass is broken or cracked or if the glass has been
removed. Striking the glass panel may result in glass
breakage. Replacement glass panel must be ordered
from Lennox andshouldonlybeinstalled by a qualified
service technician.

2 - All parts removed for servicing should be replaced be-

fore operating the appliance.
3 - Solid fuel must not be used with this appliance.
4 - Surface temperatures on the appliance are very high.

Make sure that both children and adults are aware of

the danger of burns or clothing ignition.

Page 3

5 - W arn the homeowner against leaving young children

unsupervised in the room with the appliance.

6 - Due to high temperatures, locate the appliance out of

traffic and away from furniture and draperies.

7 - Instruct the homeowner not to leave damp or wet

clothingorother flammablematerialto dryonor near
the appliance.

8 - Keep the appliance area clear and free of combustible

materials, gasoline and other flammable vapors and
liquids.

9 - Oninitialstart-up, operate theappliancecontinuous-

ly for10 to 12hoursonthe high flamesetting.During
this period, make sure that the room is well venti­lated. This “break-in” procedure is required to burn
off the odors associated with a new fireplace.

Combustion Air

Location Selection

Install the fireplace out of direct sunlight to maximize the
unit’s visible glow effect. Also, consider the following
when selecting a location for the Lennox vented gas fire­place / vented gas fireplace heater :

1 - Allrequirementsindicated inventing section mustbe

met. Thisincludesrestrictions onhorizontalandver-

tical vent lengths and vent termination locations.
2 - Centerappliance betweentwo wallstuds,if possible,

to simplify venting.
3 - If optional blower is used, consider power wiring re-

quirements.
4 - Air circulation patterns should be unobstructed.

These Lennox MerittSeries vented gas fireplaces / vented
gas fireplace heaters havebeen designed to use 100 per­cent air from outdoors for combustion.

WARNING

Do not installappliancein a corrosive or contaminated
atmosphere. Meet all combustion and ventilation air
requirements, as well as all local codes.

TYPICAL APPLIANCE APPLICATIONS

TOP VENT

APPLICATION

REAR VENT

APPLICATION

TOP VENT

APPLICATION

*RECESSED INSTALLATION

(Side walls must not extend

beyond front edges of

fireplace.)

REAR VENT

APPLICATION

5 - See figure 2 for typical appliance applications.
6 - Do not install appliance directly on carpeting.
7 - If fireplace is to be installed on tile or other combus-

tible material other than wood flooring, it must be

installed on a metal or wood panel extending the full

width and depth of the base.
8 - Providea minimum3ft.(.9m)clearanceinfrontofthe

appliance for service and proper operation.

Note - DT/DTH models have only a top flue outlet .

DR/DRH models have only a rear flue outlet.

*Note - The side walls of mantels may protrude
beyond the front face of the fireplace a maximum
of 5 inches (127mm). See figure 3 for mantel
clearances above the fireplace.

*INSTALLATION WITH ONE SIDE OF UNIT

FLUSH WITH A WALL (Opposite wall must

not extend beyond front of fireplace.)

TOP VENT

APPLICATION

VERTICAL VENT

(Top Vent

Application)

HORIZONTAL VENT

(Top Vent

Application)

TOP VENT

APPLICATION

HORIZONTAL VENT

(Rear Vent Application

With a chase)

FIGURE 2

Page 4

VERTICAL VENT

(Rear Vent

Application)

HORIZONTAL VENT

(Rear Vent Application

without a chase)

Installation Clearances

MANTEL CLEARANCES

Inches (mm)

Clearances to Combustibles

TheLennoxMerit

t

Seriesventedfireplaces /ventedfire­place heaters are approved with zero clearance to com­bustible materialsonall sides (as detailedin table 2),with
the following exception: When the unit is installed with
one sideflushwithawall, the wall on theothersideof the
unit must not extend beyondthe front edge of the unit. In
addition, when the unit is recessed, the side walls sur­rounding the unit must not extend beyond the front edge
of the unit. See figure 2.

Mantel Clearances

Vertical installation clearances to combustible mantels
varyaccordingto thedepthofthemantel. Figure3 details
these required clearances. Mantels constructed of non­combustible materials may be installed at any height
above the appliance opening; however, do not allowany­thing to hang below the eyebrow.

NOTE -Paint or lacquerusedto finishthemantel mustbe
heat resistant in order to avoid discoloration.

12 (305) MANTEL
10 (254) MANTEL

8 (203) MANTEL

14

(356)

12

(305)

10

(254)

8

(203)

6

(152)

NOTE -Eyebrow shown as positioned
in louvered front model. The eyebrow
position in the flush faced front model
is lower than shown.

6 (152) MANTEL

4 (102) MANTEL

2 (51) MANTEL

4

(102)

TOP OF

APPLIANCE

FIGURE 3

Corner Installations

Units installed across the corner of two joining walls re­quire a minimum diagonal span as detailed in figure 4.
This span accommodates the unit depth.

CORNER INSTALLATIONS

Top (DT/DTH) or Rear (DR/DRH) Vent Application

7in.

Back wall of chase/enclosure

(including any finishing materials)

DR/DRH

DT/DTH

C

Model No. A B C D E F

DT/DTH/DR/DRH 3025

DT/DTH/DR/DRH 3530

DT/DTH/DR/DRH 4035

in.
mm
in.
mm
in.
mm

30-1/8 57-1/2 40-5/8 13-1/2 28-3/4 5

765 1461 1032 343 730 127

35-1/8 57-1/2 40-5/8 13-1/2 28-3/4 5

892 1461 1032 343 730 127

40-1/8 61-3/16 43-11/32 15-7/16 30-11/16 6-3/8

1019 1554 1101 392 779 162

F

A

B

(178 mm)

RECTANGULAR

TERMINATION

b

NOTE -

D

a

Venting requirements for DR/DRH Units (Rear Vent Units)

in corner installations -

- The rectangular termination must be used.

- For the 3025, 3530, and 4035 models, the horizontal vent

E

length “a” to “b,” must not exceed 28 in. (711mm).

FIGURE 4

Page 5

Framing

Installation

Wood or metal framing must accommodate unit outer
shell as shown in figure 5. If unit is to be elevated above
floor level, a solid platform providing continuous support
(e.g. plywood decking) must be constructed.

FRAMING

Framing should be constructed of

2x4 or larger lumber.

DT/DTH VENT FRAMING -

TOP VENT WITH ONE

_

ELBOW

90

DR/DRH VENTFRAMING -

REAR VENTWITH

NO ELBOWS

B

Inches (mm)

Model No. A B C D

DR/

in. 30-1/4 33-1/4 18-1/4 ----

DRH

mm 768 845 464 ----

3025

DR/

in. 35-1/4 35-1/4 20-1/4 ----

DRH

mm 895 895 514 ----

3530

DR/

in. 40-1/4 40-1/4 25-1/4 ----

DRH

mm 1022 1022 641 ----

4035

in. 45-1/4 40-1/4 25-1/4 ----

DR

DR

4540

mm 1149 1022 641 ----

DT/

in. 30-1/4 33-1/4 ---- 38-1/4

DTH

mm 768 845 ---- 972

3025

DT/

in. 35-1/4 35-1/4 ---- 40-1/4

DTH

mm 895 895 ---- 1022

3530

DT/

in. 40-1/4 40-1/4 ---- 45-1/4

DTH

mm 1022 1022 ---- 1149

4035

in. 45-1/4 40-1/4 ---- 45-1/4

DT

DT

4540

mm 1149 1022 ---- 1149

D

C

15-7/8

(403)

A

10-1/2

(267)

5-1/8
(130)

5-1/8
(130)

(178)

7

(178)

7

12-1/8

(308)

12-1/8

(308)

FIGURE 5

Installation should beperformedbyaqualified technician
according to these instructions and local codes.

1 - Carefully remove assembled vented fireplace /

vented fireplace heater from packaging and place in
desired location.

WARNING

Combustible materials may be installed flush with
both sides and top front edges of the fireplace.
Combustible materials must NEVER overlap the
edges onto the front face of the appliance. Joints
between the finished wall and the fireplace edges

_

can only be sealed with a 300
sealant.
Non-combustible materials can be used to cover
the gap between the combustible wall materials
and t he fireplace. On flush-faced models, non­combustiblematerialsmay coverthe upperportion
of thetoppanel down to,butnot beyond the top of,
the eyebrow. You must not modify the air inlet or
outlet grills in any way. Access to panels must not
be obstructed.

2 - Lift and r emove the bus tle; in flus h-faced model

applications, remove the top panel; in louvered­face model applications, remove the louvers.

3 - Lower the bottom hinged panel. Remove three se-

curing screwsatthe bottom oftheglass panel.Care-
fully lift and remove the shrink-wrapped glass panel/
log set assembly. Lay the assembly down, and cut
and remove the shrink-wrapping.

4 - Position the logs as shown in figure 6 (3025 units),

figure 7 (3530 units), figure 8 (4035 units), or figure
9 (4540 units). Handle logs carefully, to prevent
breakage. The logs are notched to accommodate
the burner tube, pilot assembly and each other.

5 - Place rockwool(ember material) as shown in figure 10.

NOTE-Yourapplication maynot requirethe useof all
of the provided rock wool. Reserve remaining rock
wool for replacement, if necessary.

6 - Remove cardboard from pressure relief valves lo-

cated on top of the firebox.

7 - Secureappliancetofloorusingfold-downtabsonthe

sides of the fireplace. Additional holes for securing
screwsarealso providedin thebase ofthe unitunder
the firebox.

F (149_C) minimum

Page 6

DT/DTH/DR/DRH 3025 LOG PLACEMENT

Log

Number

3

4

1

Log Stamping
Part Number

1
2

196
195

3 197
4 198

Lennox
Part Number

19L61
19L60
19L62

19L63

Lennox Part Number

2

for entire log set: 18L76

1

2

3

4

FIGURE 6

Page 7

DT/DTH/DR/DRH 3530 LOG PLACEMENT

Log

4

Number

3

1

Log Stamping
Part Number

1
2

1910

199
3 1911
4 1912

Lennox
Part Number

19L65
19L64

21L10
21L11

Lennox Part Number
for entire log set: 18L77

2

1

2

3

4

FIGURE 7

Page 8