
3 4
|
Service Manual
Singular Combi Boiler - BTC 439002301 A (12.2021)
8.10 AB Error (Abnormal Operation: Heat Exchanger Temperature Sensor
Error
Description
Hex Thermistor_T2 error
Error is displayed when the Heating water sensor has short-circuited or is disconnected
Checkpoint
Check if the Hex Thermistor connector is connected normally.
1. Control board wire
2. Heating water sensor wire
Measure and check the resistance of the heating water sensor (NTC method).
—
Separate the sensor and measure it at room temperature.
Check the heating water sensor for disconnection
Check the heating water sensor for short-circuit
Figure 33
Figure 34
Check the assembly
condition of the control board
and the temperature sensor
connector and reassemble
the control board and the
temperature sensor connector
Replace the temperature
sensor
Replace the temperature
sensor
Replace the control board
Check the
temperature
sensor for short
Is the
resistance of the
temperature sensor
normal?
Yes
Yes
No
No
86 °F: 40 kΩ (± error possible)
140 °F: 12.4 kΩ
185 °F: 3.9 kΩ