Verifying Appliance Operation - Lennox Merit MLDVTCD-35NM Installation Instructions Manual

LENNOX HEARTH PRODUCTS • MERIT
Figure 29: Gas Line Connection
Gas
Valve
3/8 in. Nipple
3/8 in. Union
3/8 in. Close Nipple
Figure 30: Millivolt Gas Valve—Lower Control Compartment
Main Gas
Shut-Off Valve
Test Factory and Field Connections for
Gas Leaks
Turn on gas supply and test for gas leaks,
using a gas leak test solution—also known
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.
1. Light the appliance (refer to the lighting
instructions label, in the control
compartment or in the Care and
Operation Instructions manual).
2. 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 or remote control to the OFF
position (electronic units). Either tighten
or refasten the leaking connection, and
then retest as described above.
3. When the gas lines are tested and leak
free, rinse off the leak testing solution.
SERIES DIRECT-VENT GAS FIREPLACES • MLDVTCD-35 • INSTALLATION INSTRUCTIONS
®
Optional Gas Flex Line Connector
3/8 NPT x 3/8 in.
1/2 x 3/8 in. Flare
Flare Fitting Shut-Off Valve
3/8 in. Flex Tubing
1/2 x 3/8 in.
Reducer
3/8 in. Shut-Off Valve
Gas Valve
(Optional) Burner
ON/OFF Switch
Verify Proper Appliance Operation
For all electronic ignition
models, remove all firebox
contents, set the gas shutoff
valve in the closed position,
remove batteries from the battery
holder, and ensure the remote
/ wall receiver is in the OFF
position until ready to test/light
the fireplace.
With gas line installed, run initial system
checkout before closing up the front of the
unit. Follow the pilot lighting instructions
provided in the Care and Operation
Instructions. For piezo igniter location on
millivolt appliances, see Figure 30.
NOTE: Lighting instructions may be found
on the tags attached to a cable in the control
compartment. To access the instructions,
open the lower control compartment door
(Figure 30) by pulling simultaneously on
the left and right top corners of the door.
The door is hinged at the bottom (Remove
Control Compartment Door on Page 24).
When lighting the appliance for the first
time, it will take a few minutes for the line to
purge itself of air. Once purging is complete,
the pilot and burner will light and operate
DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Gas
Stub
Piezo
Door Latch
WARNING
as indicated in the instruction manual.
Subsequent lighting of the appliance will
not require such purging. Inspect the pilot
flame (remove logs, if necessary, handling
carefully).
Millivolt Appliance Inspection
The pilot flame should be steady, not lifting
or floating. Flame should be blue in color
with traces of orange at the outer edge.
The top 3/8 in. (10 mm) at the pilot
generator (thermopile) and the top 1/8 in.
(3.175 mm) minimum (tip) of the quick
drop out thermocouple should be engulfed
in the pilot flame.
The flame should project 1 in. (25 mm)
beyond the hood at all three ports
(Figure 31). Replace logs if removed for
pilot inspection.
To light the burner; turn ON the remote wall
switch and rotate the gas valve control knob
counterclockwise to the ON position (ON
will be at the top side of the valve).
Figure 31: Millivolt Pilot
Hood
Thermocouple
Pilot
Nozzels
Thermopile
Electronic Appliance Inspection
To light the burner, turn ON the wall or
remote control switch. Ensure the igniter
lights the pilot. The pilot flame should
engulf the flame rod (Figure 32).
Figure 32: Electronic Pilot
Ignitor
Igniter
Flame Rod Sensor
Igniter Rod
3/8 in.
(9 mm)
Min
Pilot
Hood
Pilot Hood
25