Repairs - Viessmann B1KE Combi Series Installation And Service Instructions Manual

Troubleshooting
Fault Messages Fault Messages

Repairs

IMPORTANT
Residual water will escape when the boiler or one of the
following components is fitted or removed:
Water-filled pipework

Flow switch

Heat exchanger

Circulation pumps

Plate heat exchanger (B1KE)

Components fitted in the heating water or DHW circuit.

Water ingress can result in damage to other components.
Protect the following components against ingress of water:
Control unit components (in particular in the maintenance

position and when open)
Electrical components

Plug-in connections

Electrical cables/leads

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Vitodens 100-W, B1HE/B1KE Combi Installation/Service
Shutting down the boiler
1. Switch off the power supply.
2. Shut off the gas supply.
3. If the boiler needs to be removed:
Disconnect the balanced flue system.

Drain the boiler on the heating water and DHW sides.

Disconnect the on-site cables/leads.

Checking the temperature sensors
Boiler temperature sensor (dual sensor)
1. Check the leads and plugs of supply temperature
sensors A.
2. Disconnect the leads from supply temperature
sensors A.
3. Check the sensor resistance. Note position of
guide lug B.
Sensor 1: Connections 1 and 3

Sensor 2: Connections 2 and 4

Compare the resistances with the value for the current
temperature from the following diagram. In the event of
severe deviation (> 10%), replace the dual sensor.
WARNING
The dual sensor is directly immersed in the heating
water (risk of scalding). Drain the boiler on the heating
water side before replacing the sensor.
WARNING
Risk of electric shock from escaping heating
water. Check the dual sensor for leaks.
Flue gas temperature sensor
1. Check the lead and plug of flue gas temperature
sensor C.
2. Disconnect leads, flue gas temperature sensor C.
3. Rotate sensor (anti-clockwise) by ¼ turn to remove
it (bayonet fitting).
4. Check the sensor resistance. Compare the resistance
with the value for the currently recorded temperature
from the following diagram. In the event of severe
deviation (> 10%), replace the sensor.
5. Rotate sensor (clockwise) by ¼ turn to install it.
WARNING
Escaping flue gas can cause poisoning.
When restarting, check for leaks on the flue gas side.
6. Reconnect leads, flue gas temperature sensor C.
7. If the permissible flue gas temperature has been exceeded,
the flue gas temperature sensor locks out the boiler.
Reset the burner on the programming unit once the flue
system has cooled down.