Lennox Merit MLDVT-35NM-FB Installation Instructions Manual page 36

LENNOX HEARTH PRODUCTS • MERIT
Installing Gas Conversion Kits
WARNING
The gas supply shall be shut
off prior to disconnecting
the electrical power, before
proceeding with the conversion.
AVERTISSEMENT
Avant d'effecteur la conversion,
coupez d'abord l'alimentation
en gaz, ensuite, coupez
l'alimentation electrique.
1. TURN OFF THE GAS SUPPLY TO THE
APPLIANCE and disconnect power
supply at the circuit breaker. Ensure
appliance is cold.
2. Open the lower control compartment
door (Figure 30 on Page 25) by
pushing on the right top corner of the
door. The door is hinged at the bottom.
[Optional] Remove the control
compartment door by sliding the hinge
pin, located at the door's left side, to
the right until it disengages from the
left corner post hole. Pull the control
compartment door diagonally to the left,
away from the fireplace.
3. Remove the front glass door/frame
from the appliance (Page 29).
4. Carefully remove the logs. Exercise
care so as not to break the logs
(Page 26).
5. Remove the grate and sub floor.
6. Remove the two (2) screws securing
the burner assembly. Remove the
burner assembly with the attached
venturi tube.
Millivolt and Electronic Ignition
System Appliances
7. SIT Systems—Refer to Figure 40,
Figure 41, and the instructions
provided with the SIT Regulator
Conversion Kit. Using a Torx T20
driver (with 1/4 in. shank) or slotted
screwdriver, remove and discard the
pressure regulator mounting screws
(two screws for electronic models,
three screws for millivolt models),
Lennox Hearth Products reserves the right to make changes at any time, without notice, in design,
materials, specifications, prices and also to discontinue colors, styles and products.
Consult your local distributor for fireplace code information.
LENNOX , the LENNOX design, DAVE LENNOX, the image of DAVE LENNOX and other related
®
LENNOX marks are registered or common law trademarks of Lennox Industries Inc. and are used
with permission.
Printed in U.S.A. © 2012–2013 Lennox Hearth Products LLC
P/N 506015-10 Rev. A 03/2013
SERIES DIRECT-VENT GAS FIREPLACES • MLDVT-30/35/40/45 • INSTALLATION INSTRUCTIONS
®
pressure regulator tower, the diaphragm
assembly (if applicable) and the spring.
Discard all removed components.
Figure 40: Millivolt Valve
Regulator Conversion
Pressure
Regulator
Remove
These
Components
Figure 41: Electronic Valve
Regulator Conversion
8. Install the new pressure regulator
assembly using the supplied screws.
Tighten the screws to 25 lb-in.
9. Install the enclosed identification label
to the valve body where it can be
easily seen.
10. Remove the pilot hood assembly
to access the hexed pilot orifice
(Figure 42). Remove and replace
the orifice with the one provided
with the kit. Exercise extreme care to
prevent damage to or breakage of the
igniter assembly.
Figure 42: Millivolt Pilot
Pilot
Orifice
11. Remove the orifice from the manifold
and replace it with the one provided
in the kit (Figure 43). See Table 4 on
Page 4 for orifice sizes.
Figure 43: Orifice
12. Use pipe joint compound or Teflon
tape on all pipe fittings before installing.
NOTE: Ensure propane resistant
compounds are used in propane
applications, do not use pipe joint
compounds on flare fittings.
13. Retrieve the burner and hold the venturi
tube above the orifice. Place the shutter
adjusting rod in the slot of the shutter
arm (see Table 28 on Page 30). Set
the burner assem bly into its position
and secure the trapezoidal plate with the
two screws previously removed.
14. Reinstall the baffle with the two baffle
securing screws.
15. Reassemble the remaining components.
16. Turn on gas supply and test for gas
leaks (Page 25).
17. Relight the main burner. The
lighting instructions can be found
on the lighting label in the control
compartment or in the Care and
Operation Manual provided with the
appliance. Verify proper burner ignition
and operation (Page 25).
18. Inspect the pilot system for proper
flame. The pilot flame should engulf the
flame sensor (Page 25).
19. Using a manometer, test the inlet and
manifold gas pressures (Table 2 and
Table 3).
ALWAYS TEST PRESSURES WITH THE
VALVE REGULATOR CONTROL AT THE
HIGHEST SETTING.
1508 Elm Hill Pike, Suite 108 • Nashville, TN 37210
®