Service - Lennox EL296UHE Installation Instructions Manual

6 - When the thermostat heating demand is satisfied, the
combustion air inducer begins a 5-second low speed
post-purge. The field-selected indoor blower off delay
begins. The indoor blower operates at the low-fire
heating speed.
7 - When the combustion air post-purge period is com­
plete, the inducer and the HUM contacts are de-ener­
gized. The indoor blower is de-energized at the end of
the off delay as well as the 120 ACC terminals.

Service

WARNING
ELECTRICAL SHOCK, FIRE,
OR EXPLOSION HAZARD.
Failure to follow safety warnings exactly could result
in dangerous operation, serious injury, death or
property damage.
Improper servicing could result in dangerous opera­
tion, serious injury, death, or property damage.
Before servicing, disconnect all electrical power to
furnace.
When servicing controls, label all wires prior to dis­
connecting. Take care to reconnect wires correctly.
Verify proper operation after servicing.
WARNING
The blower access panel must be securely in place
when the blower and burners are operating. Gas
fumes, which could contain carbon monoxide, can
be drawn into living space resulting in personal inju­
ry or death.
Annual Furnace Maintenance
At the beginning of each heating season, and to comply
with the Lennox Limited Warranty, your system should
be checked as follows:
1- Check wiring for loose connections, voltage at indoor
unit and amperage of indoor motor
2- Check the condition of the belt and shaft bearings if ap­
plicable.
3- Inspect all gas pipe and connections for leaks
4- Check the cleanliness of filters and change if necessary
(monthly).
5 Check the condition and cleanliness of burners and
heat exchanger and clean if necessary.
6 Check the cleanliness of blower assembly and clean
the housing, blower wheel and blower motor if neces­
.
sary
7- Inspect the condensate drain and trap for leaks and
8- Evaluate the heat exchanger integrity by inspecting the
9- Ensure sufficient combustion air is available to the fur­
10 Inspect the furnace intake and exhaust pipes to make
11 Inspect the furnace return air duct connection to ensure
12 Check the condition of the furnace cabinet insulation
13 Perform a complete combustion analysis during the fur­
14 Verify operation of CO detectors and replace batteries
.
Perform a general system test. Turn on the furnace to
check operating functions such as the start-up and shut-off
operation.
.
Page 51
cracks. The drain and trap must also be cleaned and the
trap must be primed with water. Inspect the rubber
hoses connected to the pressure switches for cracks or
loose connections, replace as necessary. Remove the
rubber hoses from the cold end header box and inspect
for any blockage, clean as needed. If strainers are in­
stalled in the hoses remember to remove and clean be­
fore re­installing the hoses.
heat exchanger per the AHRI heat exchanger inspec­
tion procedure. This procedure can be viewed at
www.ahrinet.org
nace. Fresh air grilles and louvers (on the unit and in the
room where the furnace is installed) must be properly
sized, open and unobstructed to provide combustion
.
air
sure they are in place, structurally sound, without holes,
blockage or leakage and the exhaust pipe is sloped to­
ward the furnace. Inspect terminations to ensure they
are free of obstructions and are structurally sound.
Inspect the furnace return air duct connection to ensure
the duct is sealed to the furnace. Check for air leaks on
supply and return ducts and seal where necessary
the duct is sealed to the furnace. Check for air leaks on
supply and return ducts and seal where necessary
and repair if necessary.
nace inspection to ensure proper combustion and oper­
ation. Consult Service Literature for proper combustion
values.
as required.
1 - Check the operation of the ignition system, inspect
and clean flame sensor. Check microamps before and
after. Check controls and safety devices (gas valve,
flame sensor, temperature limits). Consult Service
Manual for proper operating range. Thermal Limits
should be checked by restricting airflow and not dis­
connecting the indoor blower. For additional details,
please see Service and Application Note H­04­9.
2 - Verify that system total static pressure and airflow set­
tings are within specific operating parameters.
.
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