9
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT
®
SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
Figure 3 - SIT Millivolt Gas Valve
Variable Flame
Height Adjustment
Manifold Pressure
Port
Inlet
Pressure
Port
Main Gas Control Knob
H I
LO
W
TPTH
TP
TH
PIL
OT
PI
LO
T
ON
it
OFF
IN
OUT
Gas Inlet
Terminals TPTH, TP and TH
Gas
Outlet
Variable Flame
Height Adjustment
Manifold Pressure
Port
Inlet
Pressure
Port
Main Gas Control Knob
H I
LO
W
TPTH
TP
TH
PIL
OT
PI
LO
T
ON
it
OFF
IN
OUT
Gas Inlet
Terminals TPTH, TP and TH
Gas
Outlet
NOTE:
Install fresh batteries in the battery holder
prior to the start of burn season, so the fireplace
can automatically switch to battery power (4
"AA" batteries) in the event of a power outage.
Refer to the Lighting Instructions on
Page 23
to
light the appliance in the event of a power failure.
TO LIGHT YOUR APPLIANCE IN A POWER
OUTAGE DO THE FOLLOWING:
• Confirm batteries installed in battery pack.
• Turn unit mounted switch or wall switch
to the ON Position.
• Unit should spark at pilot and light.
NOTE: If no spark, replace batteries.
• Operate Normally.
Variable Flame Height Adjustment
All millivolt and electronic appliances are
equipped with a variable gas control valve. Flame
height for these models may be adjusted through
a range between fixed low and high settings while
the appliance is in operation. Adjust the flame
height as desired after lighting the appliance by
rotating the variable adjustment control knob
(HI/LO) located on the front of the valve (refer
to
Figures 3
and
4
).
CPI (Continuous Pilot Ignition) Switch
Models equipped with SIT electronic gas valves
may have a CPI switch located in the lower
control compartment (
Figure 1
).
This switch allows the pilot to be switched from
intermittent mode (pilot is extinguished when
the fireplace is OFF) to continuous mode (pilot
stays on when fireplace is OFF).
In periods of extreme cold, you may notice
condensation on the glass door when the
fireplace is OFF and the pilot is in intermittent
mode. Also, with the pilot in intermittent mode,
you may occasionally experience "cycle startup",
where the pilot and burner ignite but then the
burner may extinguish and reignite several times
until the flue reaches temperatures for proper
drafting. Switching the pilot to continuous
mode during periods of extreme weather may
eliminate condensation on the glass door and
"cycle startup". In more moderate weather, return
the pilot to intermittent mode.
Electronic Appliances
To light electronic appliances refer to the
detailed lighting instructions found on
Page
22
of these instructions. Electronic appliance
lighting instructions may also be found on the
pull out lighting instruction labels attached to
the gas control valve.
If your electronic appliance is equipped with an
optional remote wall switch or remote control
kit the appliance main burner may be turned on
and off with the wall switch or remote control.
If your electronic appliance is not equipped
with a wall switch or remote control, the main
burner must be turned off and on with a gas
control switch located in some other location
by the installer. Contact the installer for direc-
tions. Check batteries, if installed, routinely
(every three months).
Orange Wire
(from DFC
Wire
Harness)
Main Gas
Inlet
3/8" NPT
Green Wire
(from DFC Wire
Harness)
Inlet (IN) Test Port
Manifold (OUT)
Test Port
Figure 4 - SIT Electronic Gas Valve
Hi/Lo
Flame
Control
Knob
Yellow Ground Wire
(from DFC Wire
Harness)
