Lennox ML180DF045P24A - Service

Page 26
Y
W
C
Y
W
R
R
G
C
G
TWIN
TWIN
TWIN 2
TWIN 1
ISOLATION
RELAY
TWO-STAGE THERMOSTAT
Call For Cool
Call For Fan
Call For 1st
Stage Heat
Call For 2nd
StageHeat
R
Y
G
W1
W2
Y
W
C
Y
W
R
R
G
C
G
TWIN
TWIN
TWIN 2
TWIN 1
ISOLATION
RELAY
Call For Cool
Call For Fan
Call For Heat
R
Y
G
W
SINGLE STAGE THERMOSTAT
FIELD WIRING FOR TWINNING
FIGURE 24
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 operation,
serious injury, death, or property damage.
Before servicing, disconnect all electrical power to
furnace.
When servicing controls, label all wires prior to
disconnecting. 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 injury 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 by a licensed professional technician (or equiva-
lent) 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 applicable.
3 - Inspect all gas pipe and connections for leaks.
4 - Check the cleanliness of lters 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 necessary . The blower motors are prelubricated
for extended bearing life. No further lubrication is
needed.
7 - Inspect the combustion air inducer and clean if
necessary.
8 - Evaluate the heat exchanger integrity by inspecting
the heat exchanger per the AHRI heat exchanger
inspection procedure. This procedure can be
viewed at www.ahrinet.org.