Pressure Switches
The pressure switches are normally-open (closed during
operation), negative air pressure-activated switches. They
monitor the airflow (combustion air and flue products) through
the heat exchanger via pressure taps located on the induced
draft blower and the coil front cover. These switches guard
against insufficient airflow (combustion air and flue products)
through the heat exchanger and/or blocked condensate drain
conditions.
Flame Sensor
The flame sensor is a probe mounted on the burner/manifold
assembly which uses the principle of flame rectification to
determine the presence or absence of flame.
MAINTENANCE
WARNING
HIGH VOLTAGE!
Goodman 74
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.
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.
Drainage system. Check for blockage and/or leakage. Check
hose connections at and internal to furnace.
Wiring. Check electrical connections for tightness and/or
corrosion. Check wires for damage.
Filters