31
MAINTENANCE
Annual Inspection
The furnace should be inspected by a qualified installer, or
service agency at least once per year. This check should be
performed 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
necessary.
■
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
A return air filter is not supplied with this furnace; however, there
must be a means of filtering all of the return air. The installer will
supply filter(s) at the time of installation.
Filter Maintenance
Improper filter maintenance is the most common cause of
inadequate heating or cooling performance. Filters should be
cleaned (permanent) or replaced (disposable) every 2 months or
as required. When replacing a filter, it must be replaced with a
filter of the same type and size.
Become familiar with the 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 Removal
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 alternate filter. Follow
the filter sizes given in the Recommended Minimum Filter Size
table 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.
Induced Draft and Circulator Blowers
The bearings in the induced draft blower and circulator blower
motors are permanently lubricated by the manufacturer. No
further lubrication is required. Check motor windings for
accumulation of dust which may cause overheating. Clean as
necessary.
WFM180905CXC
(Medium)
High
4.0
2,382 28
2,315 29
2,234 30
2,158 31
2,078 32
1,971 33.82 1,866 35.73 1,762 37.84
Med
3.5
1,622 41
1,603 42
1,583 42
1,556 43
1,516 44
1,482 44.98 1,422 46.88 1,359 49.06
Med-Lo 3.0
1,436 46
1,391 48
1,387 48
1,356 49
1,325 50
1,279 52.12 1,239 53.81 1,180 56.50
Low
2.5
1,240 54
1,214 55
1,191 56
1,157 58
1,120 60
1,083 61.56 1,052 63.37 1,025 65.04
WFM18
CFM and Temperature Rise vs. External Static Pressure
Model—Heating
Speed as Shipped
Motor
Speed
Tons
AC at
0.5"
ESP
External Static Pressure (Inches Water Column)
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
CFM
Rise CFM Rise CFM Rise CFM
Rise CFM Rise CFM Rise CFM Rise CFM Rise
Goodman 74
HIGH VOLTAGE!
WARNING
To avoid personal injury or death due to
electrical shock, disconnect electrical power
before performing any maintenance. If you
must handle the igniter, handle with care.
Touching the igniter element with bare fingers,
rough handling or vibration could damage the igniter
resulting in premature failure. Only a qualified servicer
should ever handle the igniter.
Goodman 75
To avoid property damage, personal injury or death,
disconnect electrical power before removing filters. Never
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
Goodman 76
To prevent property damage, personal injury or death due
to electrical shock, disconnect electrical power before
removing the filter or performing any other maintenance.
WARNING