A.O. Smith TWI 35-200 Installation, User And Service Manual page 76

Code and
description
XA5-XXXX
(lock out error)
Temperature error
High temp limit exceeded
X48-XXXX
(blocking error)
Sensor error
Open circuit of
temperature sensor
X46-XXXX
(blocking error)
Sensor error
Short circuit of
temperature sensor
X57-XXXX
(lock out error)
Short circuit flame sensor
XAC-XXXX
(blocking error)
Air proving switch
error
Switch is not closed when
fan is running during pe-
purge
76
Cause
The temperature in the tank is above
95ºC.
Sensor is not (correctly) connected.
Damaged wiring and/or defective sensor. Replace the wiring and/or the sensor.
Short circuit in the sensor circuit.
Electrical connection between flame
sensor and tank or burner.
Hoses are damaged.
Wiring is damaged.
Leakage of air between venturi and air
connector.
Measure
Refer to indication X54-XXXX (see 12.1.3).
- Make sure that the wiring between
1 and 4 of J9 is connected and not
damaged.
- If necessary, replace or reconnect the
wiring.
- When the wiring is reconnected, reset
the controller.
- Make sure that the connector is
connected to J10.
- Make sure that the wire is connected
to the sensor.
Replace the wiring and/or the sensor.
- Make sure that the flame sensor does
not touch the tank.
- If necessary, replace the flame sensor.
- Make sure that the combustion
chamber is dry.
- Make sure that the cables of the flame
sensor are correctly connected.
- If necessary, replace the connector of
the flame sensor to the correct
connection.
- Make sure that the hoses, between
the air proving switch and fan and the
air proving switch and gas control
valve are not damaged and reset the
controller.
- If necessary replace the hose(s).
- When the hose(s) are replaced and
reconnected, reset the controller.
- Make sure that the wiring, between
the air proving switch and the
controller, is connected and not
damaged.
- If necessary, replace the wiring or
reconnect the wires.
- When wires are replaced or
reconnected, reset the controller.
- Make sure that the air connector is not
damaged. If necessary, replace the air
connector.
- Make sure that the hose is properly
connected to the venturi. If necessary,
tighten the clamp.
Installation, Maintenance and Service part