33
T
ROUBLESHOOTING
& M
AINTENANCE
ANNUAL INSPECTION
The furnace should be inspected by a qualified installer, or ser-
vice agency at least once per year. This check should be per-
formed at the beginning of the heating season. This will ensure
that all furnace components are in proper working order and
that the heating system functions appropriately. Pay particular
attention to the following items. Repair or service as neces-
sary.
• Flue pipe system. Check for blockage and/or leakage.
Check the outside termination and the connections at
and internal to the furnace.
• Heat exchanger. Check for corrosion and/or buildup
within the heat exchanger passageways.
• Burners. Check for proper ignition, burner flame, and
flame sense.
• Wiring. Check electrical connections for tightness and/
or corrosion. Check wires for damage.
• Filters.
FILTERS
T
O
AVOID
PROPERTY
DAMAGE
,
PERSONAL
INJURY
OR
DEATH
,
DISCONNECT
ELECT RICAL
POWER
BEFORE
REMOVING
FILTERS
.N
EVER
OPERATE
FURNACE
WITHOUT
A
FILTER
INSTALLED
BECAUSE
DUST
AND
LINT
WILL
BUILD
UP
ON
INTERNAL
PARTS
RESULTING
IN
LOSS
OF
EFFICIENCY
,
EQUIPMENT
DAMAGE
AND
POSSIBLE
FIRE
.
WARNING
A return air filter is not supplied with this furnace; however,
there must be a means of filtering all of the return air. The in-
staller will supply filter(s) at the time of installation.
FILTER M AINTENANCE
Improper filter maintenance is the most common cause of in-
adequate heating or cooling performance. Filters should be
cleaned (permanent) or replaced (disposable) every two months
or as required. When replacing a filter, it must be replaced with
a filter of the same type and size.
HIGHVOL TAGE!
T
O
PREVENT
PROPERTY
DAMAGE
,
PERSONAL
INJURY
OR
DEATH
DUE
TO
ELECT RICAL
SHOCK
,
DISCONNECT
ELECT RICAL
POWER
TO
THE
FURNACE
BEFORE
REMOVING
THE
FILTER
OR
PERFORMING
ANY
OTHER
MAINTENANCE
.
WARNING
Become familiar with filter location and procedures for removal,
cleaning and replacing them. If help is needed, contact the
installer of the furnace or a qualified servicer.
FILTER R EMOVAL
Depending on the installation, differing filter arrangements can
be applied. Filters can be installed in either the central return
register or a side panel external filter rack (upflow only). A
media air filter or electronic air cleaner can be used as an alter-
nate filter. Follow the filter sizes given in the Recommended
Minimum Filter size table or instruction provided by the media
or electronic air cleaner manufacturer to ensure proper unit
performance.
To remove filters from an external filter rack in an upright upflow
installation, follow the directions provided with external filter
rack kit. For further details, see your distributor.
INDUCED D RAFT AND C IRCULATOR BLOWER M OTORS
The bearings in the induced draft blower and circulator blower
motors are permanently lubricated by the manufacturer. No fur-
ther lubrication is required. Check motor windings for accumu-
lation of dust which may cause overheating. Clean as neces-
sary.
FLAME S ENSOR (QUALIFIED S ERVICER O NLY)
Under some conditions, the fuel or air supply can create a
nearly invisible coating on the flame sensor. This coating acts
as an insulator causing a drop in the flame sense signal. If the
flame sense signal drops too low the furnace will not sense
flame and will lock out. The flame sensor should be carefully
cleaned by a qualified servicer using emery cloth or steel wool.
Following cleaning, the flame sense signal should be 1 to 6
microamps at 115 volts.
IGNITER (QUALIFIED S ERVICER O NLY)
If the igniter and the surrounding air are at about 70°F and the
igniter wires are not connected to any other electrical compo-
nents, the resistance of the igniter should not exceed 75 ohms.
If it does, the igniter should be replaced.
BURNERS
T
O
PREVEN T
PERSONAL
INJURY
OR
DEATH
,
DO
NOT
REMOVE
ANY
INTERNAL
COMPARTMENT
COVERS
OR
ATTEMPT
ANY
ADJUSTMENT
.
E
LECTRICAL
COMPONENTS
ARE
CONTAINED
IN
BOTH
COMPARTMENTS
.
C
ONTACT
A
QUALIFIED
SERVICE
AGENT
AT
ONCE
IF
AN
ABNORMAL
FLAME
APPEARANCE
SHOULD
DEVELOP
.
WARNING
Periodically during the heating season, make a visual check of
the burner flames. Turn the furnace on at the thermostat. Wait
a few minutes, since any dislodged dust will alter the normal
flame appearance. Flames should be stable, quiet, soft and
blue with slightly orange tips. They should not be yellow. They
should extend directly outward from the burner ports without
curling downward, floating or lifting off the ports.