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NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT
®
PLUS DIRECT VENT GAS FIREPLACES (MPD33/35/40/45) • INSTALLATION INSTRUCTIONS
IMPORTANT: The vent termination is hot
while in operation and for a period of
time following the use of the fireplace.
To prevent contact with hot surfaces,
we recommend the use of a Termina-
tion Guard. See Page 36. This can be
purchased at your local dealer.
Figure 36
Figure 37
Installing the Square Horizontal Termination (SV4.5HT-2)
M. Install the desired termination -
1. Install the square termination (SV4.5HT-2
or SV4.5HTSS)- For the last step , from out-
side the exterior wall, slide the collars of the
termination onto the adapter (the outer over
the outer and the inner inside the inner) until
the termination seats against the exterior wall
surface to which it will be attached. Orient
the housing of the termination with the arrow
pointed upwards. Secure the termination to
the exterior wall. The horizontal termination
must not be recessed into the exterior wall
or siding by more than the 1-1/4" (32 mm) as
shown in Figure 37.
SVHRK Snorkel Cap –The snorkel cap is
designed to be fitted into a basement window
box. The SVHRK cap is for use with flex vent
The vertical distance between the inlet and outlet
of the cap is 28 in. (711 mm). pipe.
K. Attach termination adapter - Attach the
adapter (adapter - SV4.5RCH - provided with the
termination) to the vent section or telescoping
vent section), elbow or appliance collar as shown
in Figure 36 in the same manner as any SV4.5
vent component (refer to Step E).
J. Assemble vent run to exterior wall - If not
previously measured, locate the center of the
vent at the exterior wall. Prepare an opening as
described in Step B. Assemble the vent system
to point where the terminus of the last section
is within 7 in. (178 mm) to 11-1/4 in. (286
mm) inboard of the exterior surface to which
the SV4.5 HT termination is to be attached, see
Figure 37. If the terminus of the last section
is not within this distance, use the telescopic
vent section SV4.5LA, as the last vent section.
For wall thicknesses greater than that shown in
Figure 37, refer to Table 8 on page 21. This table
lists the additional venting components needed
(in addition to the termination and adapter) for
a particular range of wall thicknesses.
L. Install Firestop/Spacer at exterior wall
- When using the square termination, install
SV4.5HF (Secure Vent), SF4.5HF (Secure Flex)
Firestop/Spacer over the opening at the exterior
side of the framing, long side up, with the 3 inch
spacer clearance at the top as shown in Figure
36, and nail into place.
(The Firestop/Spacer may also be installed over
the opening at the interior side of the framing.)
Siding
Stucco
1-1/4" Maximum Recess of
the Square Termination into
Exterior Finishing Material
Exterior Surface of
Framing
6 in. to 9-1/4 in.
(152 to 235 mm)**
Exterior Surface of Siding
Interior Surface of
Finished Wall
Maximum wall thickness
10 in.(254 mm)**
SV4.5HT-2
Square Termination
Maximum Extent of
Vent Run Sections
Relative to Exterior
Surface of Framing
Last Vent Section. Use
Te les co pi c Ven t
Section (SV4.5LA), If
Necessary
Adapter
SV4.5RCH
SV4.5HT-2
Square Termination
Venting Connection and Exterior Wall Recessing of the
Horizontal Square Termination (SV4.5HT-2).
*Use silicone caulking to seal
the top and sides of the
termination, up to the
underlayment, stucco, or
masonry wall surface.
**For thicknesses greater
than 10 inches, see Table 8.
*Caulk
*Caulk
Firestop/Spacer (SV4.5HF) shown
on the exterior side of the wall. It
may also be installed on the
interior side.
SV4.5HT-2
Termination
10-1/2"
(267mm)
7"
(178)
5-1/8"
(130 mm)
12-1/8"
(308 mm)
Note: Centerline of Vent Piping is
NOT the Same as the Centerline of
the Framed Opening.
6 to 48 inch Vent Section,
Telescopic vent section,
Elbow or Appliance Collar
See Figure 13 on page 11
for Min. Distance to Base
of Appliance.
Base of Appliance
3"
(76 mm)
1"
(25.4 mm)
Adapter
SV4.5RCH
Horizontal terminations have been designed to perform in a wide range of weather
conditions. Our terminations meet or exceed industry standards.
When selecting the locations of your horizontal terminations, do not place the termination
where water from eaves and adjoining rooflines may create a heavy flow of cascading water
onto the termination cap. If the cap must be placed where the possibility of cascading water
exists, it is the responsibility of the builder to direct the water away from the termination
cap by using gutters or other means.
Take care to carefully follow the installation instructions for the termination, including the
use of silicone caulking where required.