Table of Contents
Advertisement
Auxiliary Limit
The auxiliary limit controls are located on or near the
circulator blower and monitors blower compartment
temperatures. They are a normally closed (electrically),
manual-reset sensors. These limits guard against
overheating as a result of insufficient conditioned air
passing over the heat exchanger.
Burner Temperature Switch
The burner temperature switch is mounted on the burner
assembly to monitor the burner box temperature. It is
normally closed (electrically), auto-reset sensor. This
switch guards against the burner flames not being properly
drawn into the heat exchanger.
Pressure Sensor
Pressure sensor is mounted on the induced draft blower.
Its function is to regulate the induced draft blower's speed
in order to maintain proper air-fuel ratio for clean and
reliable combustion.
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 to the burner
assembly which uses the principle of flame rectification to
determine the presence or absence of flame.
TROUBLESHOOTING
Troubleshooting Chart
Refer to the Troubleshooting Codes chart for assistance in
determining the source of unit operational problems.
MAINTENANCE
High Voltage!
To avoid personal injury or death due to electri-
cal shock, disconnect electrical power BEFORE
performing any service or maintenance.
WARNING
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,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. Check for Blockage
Filter Maintenance
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.
Improper filter maintenance is the most common cause of
inadequate heating or cooling performance. Filters should
be cleaned (permanent) or replaced (disposable) every two
months or as required.
Burner
To prevent personal injury or death, do not remove any in-
ternal compartment covers or attempt any adjustment. Elec-
trical components are not contained in both compartments.
Contact a qualified service agent at once if an abnormal
flame appearance should develop.
The Ultra Low NOx furnace uses a premix burner. The
burner box is sealed to achieve safe and reliable operation.
35
FILTERS
WARNING
Advertisement
Table of Contents
