Lennox MERIT Series Installation Instructions Manual page 15

LENNOX MERIT
Step 5. All millivolt Systems – Attach
manometer to the manifold side pressure
test fitting and verify manifold pressure
reads 3.5 inches water column (0.87 kPa) for
natural gas, and 10.0 inches water column
(2.49 kPa) for propane gas.
Step 6. Refer to Figure 25 and remove the
pilot hood assembly to access the hexed pilot
orifice. Remove and replace the orifice with
the one provided with the kit.
electronic Appliances
Step 7. Honeywell electronic valves - See
Figure 27 and the instructions provided
with the kit. Remove the slotted cap screw,
o-ring, pressure-regulating adjusting screw
and spring. Retain all parts for possible later
use. Install new components from the kit.
Black cap and red spring for propane gas
units. Silver cap and stainless steel spring
fro natural gas units.
Before installing the cap, attach manometer
to the manifold side pressure test fitting
and adjust screw until pressure reads 3.5
inches water column (0.87 kPa) for natural
gas, and 10.0 inches water column (2.49
kPa) for propane gas.
Pilot
Orifice
Flare Nut
Note: If the ignitor assembly is damaged, a replacement kit is available; order Catalog Number 87L54.
Figure 26
SERIES B-VENT GAS FIREPLACES • 36" LMBV MODELS • INSTALLATION INSTRUCTIONS
®
Manifold
Pressure
Test Port
Slotted
Cap
Figure 27
See Figure 26 and replace the pilot orifice
as follows: Remove the ignitor assembly
retainer clip, and carefully remove the ignitor
assembly.exercise extreme care to prevent
damage to or breakage of the ignitor as-
sembly. Remove the screw securing the
pilot assembly to its mounting bracket. Back
off the flare nut at the end of the pilot gas
line to free the pilot assembly from the gas
line. Remove the pilot orifice and replace it
with the one provided with the conversion
kit. Reinstall the pilot assembly by reversing
the steps detailed here.
Pilot
Assembly
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Inlet Pressure Test Port
All models
Step 8. Unscrew the orifice from the manifold
and replace it with the one provided with the kit,
#42 (0.0935) for natural gas units and (0.058)
Spring
for propane (see Figure 28 ).
Adjusting
Screw
Figure 28
Step 9. Reassemble all removed components
by reversing the procedures outlined in the
preceding steps. Use pipe joint compound or
Teflon tape on all pipe fittings before installing
(ensure propane resistant compounds are used
in propane applications, do not use pipe joint
compounds on flare fittings). Check for leaks
(refer to page 8, Step 6).
Step 10. Attach appropriate conversion kit
label (see Figure 29 ) next to the rating plate
on the appliance.
Ignitor
Assembly
Retaining
Clip
Figure 29
Step 11. Turn on gas supply and test for gas
leaks.
When reinstalling the ignitor assembly,
use extreme care to prevent damage and
breakage. do not apply any leverage to
the ignitor assembly while restoring the
retainer clip to its original position.
THIS APPLIANCE HAS BEEN CONVERTED TO:
NATURAL GAS
INPUT BTU/HR – 24,000
MANIFOLD PRESSURE – 3.5"
ORIFICE SIZE – #42 (0.0935)
THIS APPLIANCE HAS BEEN CONVERTED TO:
PROPANE/LPG
INPUT BTU/HR – 24,000
MANIFOLD PRESSURE – 10"
ORIFICE SIZE – (0.058)
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