With Gas Furnace; Gas Furnace Lockout Reset - Daikin RXSQ24TAVJU Service Manual

SiUS331708EA
2.3

With Gas Furnace

1 The gas furnace does not start operation.
Operation does not switch from heat pump to gas furnace in
spite of low room temperature. Operation does not switch
2
from gas furnace to heat pump even though the room
temperature is nearing the set temperature.
AA-03 (Gas furnace abnormality) is indicated on the remote
3 controller while no error is indicated on the PCB of the gas
furnace.
The gas furnace does not stop even when the room
4
temperature exceeds the set temperature.
The airflow rate indication on the remote controller is not
5
consistent with the actual airflow rate of the indoor unit.
2.4

Gas Furnace Lockout Reset

Furnace lockout is characterized by a non-functioning furnace (circulator blower may be running continuously)
providing a diagnostic LED code located on the furnace board.
Lockout results when a furnace control detects abnormal conditions. If the furnace is in "lockout", the following
methods can be used to clear the error.
a. Turn the remote controller off to clear the error. If the error is not cleared, proceed to next step.
b. Set the setting temperature to maximum, then turn the remote controller on.
c. Turn the remote controller off.
d. Turn the remote controller on after around 15 seconds from procedure c.
The procedures b, c, and d will not work during certain outdoor unit operations, i.e. defrost, startup, compressor
stop, service mode etc.
If the LED of the ON/OFF button is flashing when you turn the remote controller on, you cannot clear the error
with the method above. In that case, the error must be cleared using the gas furnace. Refer to the gas furnace
operation manual for more details.
Service Diagnosis
Symptom Supposed Cause
The gas furnace does not start operation while the compressor
is during operation or under stop-control, or right after defrost IN
or defrost OUT. Wait until the operation becomes stable.
This function is performed only with outdoor units which support
automatic switching between gas furnace and heat pump
interlocking with room temperature.
Some models are enabled to support automatic switching
between gas furnace and heat pump interlocking with outdoor
air temperature by setting heat pump lockout on an outdoor unit
side. However, the compressor stops while gas furnace is
during operation.
It is possible that temperature setting for switching from heat
pump to gas furnace and from gas furnace to heat pump is not
appropriate. Confirm the field setting 11(21)-1 and 11(21)-2 and
change the temperature setting for switching as needed. Refer
to 2-Step Thermostat Processing (CXTQ-TA Models) on
page 84 for details.
Operation does not switch from gas furnace to heat pump for a
predetermined period of time after ignition of gas furnace to
avoid frequent switching. The period of time can be changed at
the field setting 11(21)-3. Refer to Gas Furnace Control
(CXTQ-TA Models) on page 82 for details.
In some cases of gas furnace abnormality, error indication on
the remote controller is retained even after the abnormality is
removed. Execute combustion heating operation once or reset
the power source.
The gas furnace does not stop during defrost/oil return
operation to prevent cold air from blowing out due to fan residual
operation. At the field setting 11(21)-3, the gas furnace setting
can be changed not to operate during defrost/oil return
operation.
The airflow rate of the indoor unit during gas furnace
combustion heating depends on the intensity of combustion.
Therefore, the airflow rate of the indoor unit does not reflect the
airflow setting of the remote controller.
Symptom-Based Troubleshooting
148