Other Unit Adjustments - Lennox ELITE Series Installation Instructions Manual

Testing for Proper Venting and Sufficient Combus-
tion 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 EL296UHE gas furnace has been started, the
following test should be conducted to ensure proper vent-
ing and sufficient combustion air has been provided to the
EL296UHE as well as to other gas-fired appliances which
are separately vented.
If a EL296UHE 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
flue 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 sufficient 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 deficiencies
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 fireplace 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 flame of match or candle to test for spillage
of flue 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
sufficient 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, fireplace dampers and any
other gas-burning appliance to their previous condition
of use.

Other Unit Adjustments

Primary Limit.
The primary limit is located on the heating compartment
vestibule panel. This limit is factory set and requires no
adjustment.
Flame Rollout Switches (Two)
These manually reset switches are located on the front of
the burner box.
Pressure Switch
The pressure switch is located in the heating compartment
on the cold end header box. This switch checks for proper
combustion air inducer operation before allowing ignition
trial. The switch is factory-set and must not be adjusted.
Temperature Rise
Place the unit into operation with a second-stage heating
demand. After supply and return air temperatures have
stabilized, check the temperature rise. If necessary, adjust
the heating blower speed to maintain the temperature rise
within the range shown on the unit nameplate. See TABLE
18 on page 59 for allowable heating speeds. Increase
the blower speed to decrease the temperature rise. De-
crease the blower speed to increase the temperature rise.
Failure to properly adjust the temperature rise may cause
erratic limit operation.
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