Lennox Merit ML296UH110XV60C - Maintenance and System Testing; Maintenance and Testing

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Testing for Proper Venting and Su󰀩cient Combustion Air for Non-Direct Vent Applications
WARNING
CARBON MONOXIDE POISONING HAZARD!
Failure to follow the steps outlined below for each
appliance connected to the venting system being placed
into operation could result in carbon monoxide poisoning
or death.
The following steps shall be followed for each appliance
connected to the venting system being placed into
operation, while all other appliances connected to the
venting system are not in operation.
After the ML296UHV gas furnace has been started, the
following test should be conducted to ensure proper vent-
ing and su󰀩cient combustion air has been provided to the
ML296UHV as well as to other gas-red appliances which
are separately vented.
If a ML296UHV furnace replaces a Category I furnace
which was commonly vented with another gas appliance,
the size of the existing vent pipe for that gas appliance
must be checked. Without the heat of the original furnace
ue products, the existing vent pipe is probably oversized
for the single water heater or other appliance. The vent
should be checked for proper draw with the remaining ap-
pliance.
The test should be conducted while all appliances (both
in operation and those not in operation) are connected to
the venting system being tested. If the venting system has
been installed improperly, or if provisions have not been
made for su󰀩cient amounts of combustion air, corrections
must be made as outlined in the previous section.
1 - Seal any unused openings in the venting system.
2 - Visually inspect the venting system for proper size and
horizontal pitch. Determine there is no blockage or
restriction, leakage, corrosion, or other deciencies
which could cause an unsafe condition.
3 - To the extent that it is practical, close all building
doors and windows and all doors between the space
in which the appliances connected to the venting
system are located and other spaces of the building.
4 - Close replace dampers. 5 - Turn on clothes dryers
and any appliances not connected to the venting
system. Turn on any exhaust fans, such as range
hoods and bathroom exhausts, so they will operate at
maximum speed. Do not operate a summer exhaust
fan.
6 - Follow the lighting instruction to place the appliance
being inspected into operation. Adjust thermostat so
appliance will operate continuously.
7 - Use the ame of match or candle to test for spillage
of ue gases at the draft hood relief opening after 5
minutes of main burner operation.
8 - If improper venting is observed during any of the
above tests, the venting system must be corrected or
su󰀩cient combustion/make-up air must be provided.
The venting system should be re-sized to approach the
minimum size as determined by using the appropriate
tables in appendix G in the current standards of the
National Fuel Gas Code ANSI-Z223.1/NPFA 54 in the
U.S.A., and the appropriate Natural Gas and Propane
appliances venting sizing tables in the current
standard of the CSA-B149 Natural Gas and Propane
Installation Codes in Canada.
9 - After determining that each appliance remaining
connected to the common venting system properly
vents when tested as indicated in step 3, return doors,
windows, exhaust fans, replace dampers and any
other gas-burning appliance to their previous condition
of use.
Repair Parts List
The following repair parts are available through Lennox dealers. When ordering parts, include the complete furnace model
number listed on the CSA nameplate -- Example: ML296UH045XV36B. All service must be performed by a licensed
professional installer (or equivalent), service agency, or gas supplier.
Cabinet Parts
Outer access panel
Blower access panel
Top Cap
Control Panel Parts
Transformer
Integrated control board
Door interlock switch
Blower Parts
Blower wheel
Motor
Motor mounting frame
Motor capacitor
Blower housing cuto󰀨 plate
Heating Parts
Flame Sensor
Heat exchanger assembly
Gas manifold
Combustion air inducer
Gas valve
Main burner cluster
Main burner orices
Pressure switch
Ignitor
Primary limit control
Flame rollout switches