Page 2
DT/DTH/DR/DRH Unit Dimensions - inches (mm)
A
B
C
D
E
F**
G
16
(406)
1/2 (13)
1-5/8
(42)
9-3/4
(248)
3 (76)
TOP VIEW
NOTE - Eyebrow
hood shown as positioned
in louvered front model.
*
CONCENTRIC FLUE
FLUE - 4-1/2 (114)
COMBUSTION AIR - 7-1/2 (190)
FRAMING
SPACERS
(Top and Sides
and Rear)
GAS INLET
(Either Side
and bottom)
*
DT/DTH - top flue only
DR/DRH - rear flue only
FRONT VIEW
RIGHT SIDE VIEW
3 (76)
2 (51)
(Louvered Front Model Shown)
**
DR/DRH - rear flue only
7 (178)
2 (51)
ELECTRICAL
INLET
2-3/4x2 (70x51)
COVER PLATE with
KNOCKOUT)
Model No.
A
B
C
D
E
**F
G
DT/DR3025
in.
19-7/8
30-1/8
30-1/8
24-1/2
14
18-1/4
9-15/16
DT/DR3025
DTH/DRH3025
mm
505
765
765
616
356
464
252
DT/DR3530
in.
24-7/8
35-1/8
32-1/8
29-1/2
16
20-1/4
12-7/16
DT/DR3530
DTH/DRH3530
mm
632
892
816
749
406
514
316
DT/DR4035
in.
29-7/8
40-1/8
37-1/8
34-1/2
21
25-1/4
14-15/16
DT/DR4035
DTH/DRH4035
mm
759
1019
943
876
533
641
379
in.
34-7/8
45-1/8
37-1/8
39-1/2
21
25-1/4
17-7/16
DT/DR4540
mm
886
1146
943
1003
533
641
443
FIGURE 1
Merit
t
Series - DT/DTH/DR/DRH
Merit
t
Series fireplaces are sealed-combustion (direct
vent), heat-circulating gas appliances. The appliances
utilize a 100 percent safety shut-off gas control with either
a Piezo ignition system or an electronic ignition system.
Models equipped with either electronic ignition or the op-
tional forced air fan assembly require 120V electrical con-
nection. Decorative trim kits, a brickaded firebox lining,
forced air fan assemblies, a wall thermostat (for use with
vented gas fireplace heater models only), and hand-held
remote ON/OFF controls are available as options. Refer
to table 1 for model designations.
The fireplace has provisions for side(s) or bottom entry for
gas piping. This appliance must be vented to the outside
and must not be connected to a flue servicing another ap-
pliance.
The appliance must be installed using only approved Lennox
concentric venting components (4-1/2 in. / 7-1/2 in.).
The millivolt gas valve used in non-electronic igni-
tion 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 al-
teration of construction will void 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 models with the optional 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
Models Listed to
Vented Gas
Fireplace Heater
Standard
Suffixes Used with
Both Models
DT/DR3025
DT/DR3530
DT/DR4035
DT/DR4540
DTH/DRH3025
DTH/DRH3530
DTH/DRH4035
C - Louver front
F - Flush-Faced Front*
N - Natural Gas
P - Propane Gas (LP)
M - Millivolt System
E - Electronic system
*DRH/DTH models available with louver front only.
