blower airflow after the heating cycle is completed. In
When the thermostat “calls for
When the thermostat “calls for
Continuous Blower Speed Selection from Thermostat To select different
57.The selection can be changed as many times as desired and is stored in the memory to be automatically used fol- lowing a power interruption.
NOTE: If the
7.Heat pump
See Fig. 29 - 32 for thermostat connections.
When installed with a heat pump, the furnace control auto- matically changes the timing sequence to avoid long blower off times during demand defrost cycles. Whenever W/W1 is energized along with Y1 or Y/Y2, the furnace control CPU will transition to or bring on the blower mo- tor BLWM at cooling airflow,
still energized the furnace control CPU will transition the blower motor BLWM to
8.Component test
The furnace features a component test system to help dia- gnose a system problem in the case of a component fail- ure. To initiate the component test procedure, ensure that there are no thermostat inputs to the control and all time delays have expired. Turn on setup switch
NOTE: The component test feature will not operate if the control is receiving any thermostat signals or until all time delays have expired.
The component test sequence is as follows:
a.The furnace control CPU turns the inducer motor ON at
b.After waiting 10 seconds the furnace control CPU turns the hot surface igniter ON for 15 seconds, then OFF.
c.The furnace control CPU then turns the blower motor BLWM on at
d.After shutting the blower motor OFF the furnace con- trol CPU switches the inducer to
NOTE: The EAC terminals are energized when the blower is operating.
After the component test is completed, 1 or more status codes (11, 25, or 41) will flash. See component test section or Service Label (Fig. 52) for explanation of status codes.
NOTE: To repeat component test, turn setup switch
Wiring Diagram
Refer to wiring diagram Fig. 53.
Troubleshooting
Refer to the service label. (See Fig.
The Troubleshooting Guide (See Fig. 58.) can be a useful tool in isolating furnace operation problems. Beginning with the word “Start,” answer each question and follow the appropriate arrow to the next item.
The Guide will help to identify the problem or failed component. After replacing any component, verify correct operation sequence.
A more detailed Troubleshooting Guide is available from your distributor.
315AAV
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