86
3.
In the event of severe deviation replace the sensor.
Danger
The boiler water temperature sensor is
directly immersed in the heating water (risk
of scalding).
Drain the boiler before replacing the sensor.
Checking the flue gas temperature sensor
The flue gas temperature sensor locks out the boiler if
the permissible flue gas temperature is exceeded.
Cancel the lockout after the flue system has cooled
down by pressing reset button
R
.
Fig. 60
1.
Pull lead from flue gas temperature sensor
A
.
2.
Check the sensor resistance and compare it to the
curve.
10
1
10 30 50 70 90 110
Temperature in °C
0.4
0.6
0.8
2
4
6
8
20
Resistance
in kΩ
Fig. 61
Sensor type: NTC 10 k
Ω
3.
In the event of severe deviation replace the sensor.
Checking the temperature limiter
If the burner control unit cannot be reset after a fault
shutdown although the boiler water temperature is
below approx. 90 °C, check the following:
Troubleshooting
Repairs
(cont.)
6136330
Service