Maintenance And Servicing; Maintenance Checklist; Glass Maintenance - Lennox Hearth Products Merit Series Installation And Operation Manual

MAINTENANCE AND SERVICING
Maintenance Checklist
The following should only be performed by a qualified service
technician.
CAUTION: Label all wires prior to disconnection when servic-
ing controls. Wiring errors can cause improper and dangerous
operation. Verify proper operation after servicing.
1. Annual inspection should be made and the following checks per-
formed:
oWhen unit is cool, remove glass and inspect burner for dirt, soot and
lint accumulations and remove if necessary. If excessive soot accumu-
lation is present on burner, have a qualified service technician adjust
the burner for proper combustion.
o Clean inside of glass with gas fireplace glass cleaner. NEVER attempt
to remove or clean the glass when the unit is hot.
o Check the hot air outlet vents for lint or other accumulations. Never
block or restrict vent openings, obstruct flow of ventilation air, or use
vents other than those approved for use with the Medina gas insert.
o Check that the chimney and its outlet are open and free of soot, block-
age, or debris.
o Check gaskets once a year. Gaskets must be tight. Replace if neces-
sary.
o Inspect the pilot system for proper flame. NEVER ADJUST THE PILOT
until after the gas pressure has been checked and the supply lines have
been completely bled (this may take an hour or more when bleeding
through the pilot). All pilots are checked and burned at the factory
prior to shipment. The pilot adjustment screw is located below the
ON/OFF/PILOT control knob. Remove the pilot adjusting cover with
a flat-bladed screwdriver to access the pilot adjusting screw. Adjust
the pilot screw to properly size the flames. The flames should directly
contact the thermopile and extend across the main burner ports. Be
careful not to back the screw out of its threads. Replace the cover and
check for gas leaks using a gas leak test solution.
o Check that the area around the insert is kept clear and is free of com-
bustible materials, gasoline and other flammable vapors and liquids.
o Check the millivolt system as per the table on this page.
. The viewing glass should be cleaned periodically (see Glass Main-
tenance).
Check
Test
A
B
C
Figure 19
Glass Door Cleaning and Maintenance
Cleaning:
and a household glass cleaner. For cleaning white condensation from the
interior glass, use a gas fireplace glass cleaner available from your insert
dealer. Use of caustic or abrasive cleaners may damage the glass. DO
NOT operate the insert with broken glass. DO NOT clean door or glass
when hot. DO NOT abuse the glass door by striking or slamming it shut.
DO NOT use substitute materials if replacing the glass. DO NOT spray
commercial glass cleaner with ammonia on the door and glass gasket
as it may dissolve the gasket glue.
Glass Replacement:
separately. Should the glass be damaged, the entire glass, gasket and
metal frame assembly must be replaced as a unit. This replacement glass
assembly is available from your Lennox Hearth Products dealer. The glass
is neo-ceramic and alternative types must not be used.
WARNING: Do not operate appliance with the glass panel
removed, cracked, or broken. Do not remove glass door while
the insert is hot. Replacement of the glass door should be done
by a qualified service technician.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Millivolt and System Checks
To Connect
Test Meter
Leads to
Terminals
Complete  & 3
System
Thermopile 1 & 
Output
System  & 3
Resistance
Proper Pilot Flame Appearance
When cool, the glass may be cleaned with a clean, soft cloth
The glass in the insert door cannot be replaced
Thermostat Meter Read-
Connects ing
Should Be
Closed 100 MV
or More
Open Greater Than
35 MV
Closed .5 Ohms
17