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18-EB40D1-1A-EN
circulation of 40 – 50% airflow of selected tap
regardless of compressor and condenser fan operation.
SSaaffeettyy SSeeqquueenncceess
This product is equipped with safety devices to protect
against abnormal conditions.
The temperature limit switch (TCO) is located on the
blower barrier, and can be accessed through the
blower compartment. This automatic reset device
protects against excessive leaving air temperature. If
this device opens, the gas valve is immediately closed
and will not permit operation until the limit switch
closes.
The rollout switch (RO) is located in the gas
compartment near the inlet of the burners. This is a
manual reset device designed to protect against any
form of flame rollout. If this device is opened the gas
valve is immediately de-energized and the control
(IGN) will lockout the system. The rollout switch (RO)
must be reset before operation is allowed to continue.
The pressure switch (PS) is located in the upper right
side of the gas compartment. This automatic device
assures adequate combustion air pressure. If pressure
against the induced draft blower outlet becomes
excessive, the pressure switch will react and shut off
the gas valve, until acceptable combustion pressure is
again available.
If the control (IGN) does not sense flame within the first
trial for ignition period, the gas valve will be de-
energized. The control (IGN) will initiate a 60 seconds
interpurge. Following the interpurge, the control will
perform a second ignition attempt. If the second try is
not successful, the control will start another 60 second
interpurge. After the interpurge, a third attempt will be
tried. If the third try is not successful, the control will
lock out.
If loss of flame occurs during a heating cycle, the
control (IGN) will close the gas valve and cycle through
the ignition trial as stated above.
If control lock out occurs, the control (IGN) will retry a
complete ignition sequence in 1 hour.
The control (IGN) can be reset by removing power to
the unit or by turning the thermostat from “on” to “off”
for approximately three seconds, then back “on”.
Final Installation Checklist
☐ Does the unit run and operate as described in the
section on "Sequence of Operation" in response to
the room thermostat?
☐ Are the condenser fan and indoor blower operating
correctly with proper rotation and without undue
noise?
☐ Is the compressor operating correctly and has the
system been checked with a charging chart?
☐ Has the voltage and running current been checked
to deter mine if it is within limits?
☐ Has the thermostat been checked for calibration
and the air discharge grilles adjusted to balance the
system?
☐ Has the ductwork been checked for air leaks and
condensation?
☐ Has the furnace manifold pressure been checked
and adjusted if necessary?
☐ Has the heating air temperature rise been checked?
☐ Has the unit been checked for tubing and sheet
metal rattles? Are there any other unusual noises to
be checked?
☐ Are all covers and panels in place and properly
fastened?
☐ Has the owner been instructed on the proper
operation and maintenance of the unit? Be sure to
leave this manual with the owner.
Maintenance
Service Maintenance
Service maintenance should be performed by qualified
service personnel.
CCoooolliinngg SSeeaassoonn
To keep the unit operating safely and efficiently, the
manufacturer recommends that a qualified service
technician check the entire system at least once each
year or more often if needed. The service technician
should examine these areas of the unit:
• filters (for cleaning or replacement)
• motors and drive system components
• economizer gaskets (for possible replacement)
• safety controls (for mechanical cleaning)
• electrical components and wiring (for possible
replacement and connection tightness)
• condensate drain (for proper sealing and cleaning)
• unit duct connections (to see that they are
physically sound and sealed to the unit casing)
• unit mounting support (for structural integrity)
• the unit (for obvious unit deterioration)
HHeeaattiinngg SSeeaassoonn
Complete the following unit inspections and service
routines described at the beginning of each heating
season.
• Visually inspect the unit to ensure that the airflow
required for combustion and condenser coil is not
obstructed from the unit.
• Inspect the control panel wiring to verify that all
electrical connections are tight and that the wire
insulation is intact.
• Check the operation of the gas ignition system as
follows: Turn off the gas supply with the unit
operating to verify that the gas valve closes and
that a re-ignition cycle is initiated by the unit.
• Visually inspect the inside of the burners and the
UUnniitt SSttaarrttuupp