12
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT PLUS
®
B-VENT GAS FIREPLACES (MPB33/35/40/45) • INSTALLATION INSTRUCTIONS
Turn on gas supply and test for gas leaks, using
a gas leak test solution (also referred to as
bubble leak solution).
NOTE:
Using a soapy water solution is
an effective leak test solution but it is not
recommended, because the soap residue
that is left on the pipes/fittings can result in
corrosion over time.
A.
Light the appliance (refer to the lighting
instructions label in the control compartment
or in the Care and Operation Instructions
manual).
B. Brush all joints and connections with the gas
leak test solution to check for leaks. If bubbles
are formed, or gas odor is detected, turn the
gas control knob (off/pilot/on) to the “OFF”
position (millivolt units), or turn the receiver,
remote control or control switch to the “OFF”
position (electronic units). Either tighten or
refasten the leaking connection, then retest as
described above.
C.
When the gas lines are tested and leak free,
be sure to rinse off the leak testing solution.
6.
If wall-mounted ON/OFF control is to be
used, mount it in a convenient location on
a wall near the fireplace.
7
. If an optional control is to be used, wire it in
the low voltage circuit as shown in
Figure
18
.
NOTE:
The supplied 15 feet of 2 conductor wire
has one end of each conductor connected to
the gas valve circuit and the other end of each
conductor placed loose inside the bottom
compartment.
8
. After the wiring is complete, replace the
cover plate.
BLOWER CONTROL CIRCUIT WIRING
120V, 60HZ, 1PH
Factory Wired
Ground
Field Wired
Junction Box
Tab Intact
Tab
Broken
Plug blower
into this
receptacle
ne
er
G -
dn
uor
G
* Wall-mounted
ON/ OFF Blower
Switch or Variable
Speed Control Switch.
Blower
eti
h
W -
lar
tu
eN 120 VAC - Blac
k
Green
Ground
Screw
Whit
e
Gree
n
Neutral
Side of
Receptacle
Hot
Side of
Receptacle
Red
Black
Figure 19 - Junction Box Wiring
WARNING
Electronic models of these appli-
ances are equipped with a three-
prong (grounding) plug utilized
in connecting the electronic
components to the junction box
in the lower compartment. This
grounding plug provides protec-
tion against shock hazard and
should be plugged directly into
the properly grounded three-
prong receptacle. DO NOT cut
or remove the grounding prong
from the plug.
STEP 6. CONNECTING GAS LINE
Make gas line connections. All codes require a
shut-off valve mounted in the supply line. The
orientation of the shut-off valve should face the
front (see
Figure 22
).
Figure 21
illustrates two
methods for connecting the gas supply. The flex-
line method is acceptable in the U.S.; however,
Canadian requirements vary depending on
locality. Installation must be in compliance
with local codes.
A sediment trap is recommended in the gas
piping within the home to prevent moisture
and debris in the line from damaging the valve.
These appliances are equipped with a gas flex
line for use (where permitted) in connecting the
unit to the gas line. A gas flex line is provided
to aid in attaching the direct vent appliance to
the gas supply. The gas flex line can only be
used where local codes permit. Refer to
Figure
21
for flex line description. The flex line is rated
for both natural and propane gas. A manual
shut off valve is also provided with the flex line.
The gas control valve is located in the lower
control compartment.
STEP 5. WIRING OPTIONAL FORCED
AIR BLOWER KIT
FBK-100, FBK-200, and FBK-250 Kits
(see Figure 18)
An electrical outlet box is provided for the
installation of the FBK-100, FBK-200 and FBK-
250 forced air blower kits. Electrical power
must be provided to this box to operate these
blowers. Install the blower kits according to the
installation instructions provided with the kits.
NOTE:
The tab connecting the two receptacles
of the outlet box must be broken in the
FBK-100 and FBK-200 blower kit applications
(see
Figure 19
).
To access the valve, open the control
compartment access panel. Actuate the spring
loaded magnetic catches securing the panel.
First, gently depress the upper right top corner
of the panel until the magnet catch "pops" the
door free. Then, gently pulling the panel forward,
disengage the left magnet catch and allow the
panel to swing down to open.
The control valves have a 3/8" (10 mm) NPT
thread inlet and outlet side of the valve (refer to
Figure 1 [Millivolt] and Figure 2 [Electronic]
on Page 4)
.
Secure all joints tightly using appropriate
tools and sealing compounds (ensure propane
resistant compounds are used in propane
applications). Optional: Seal around the gas
line to prevent cold air leakage. Gas line holes
and other openings can be caulked or stuffed
with unfaced fiberglass insulation.
TEST ALL CONNECTIONS FOR GAS LEAKS
(FACTORY AND FIELD)
WARNING
Never use an open flame to
check for leaks.
