Ac Error (Abnormal Operation: Dhw Sensor) - Bosch Singular 4000 Service Manual

Service Manual

8.11 AC Error (Abnormal Operation: DHW Sensor)

Error
DHW Sensor T3 error
Checkpoint
Figure 40
Figure 41
3 6 |
Description
Error is displayed when the DHW sensor has short-circuited or is disconnected
 Check if the DHW Thermistor connector is connected normally.
1. Control board wire
2. Heating water sensor wire
 Measure and check the resistance of the Hot Water DHW Sensor (NTC method).
Separate the sensor and measure it at room temperature.
—
 Check the DHW sensor for disconnection
 Check the DHW sensor for short-circuit
Check the assembly
condition of the control board
and the temperature sensor
connector and reassemble
the control board and the
temperature sensor connector
Check the
temperature
sensor for short
Yes
Is the
resistance of the
temperature sensor
normal?
Yes
Replace the control board
No
Replace the temperature
sensor
No
Replace the temperature
sensor
86 °F: 40 kΩ (± error possible)
140 °F: 12.4 kΩ
185 °F: 3.9 kΩ
Singular Combi Boiler - BTC 439002301 A (12.2021)