Correction - Viessmann Vitodens 200 Start-Up/Service Instructions

Vitodens 200 WB2 Service

Correction

(continued)
Scanning the actual and desired temperatures
Check outdoor temperature sensor
1. Disconnect connector "X6" from the control unit.
2. Measure resistance of outdoor temperature sensor A
at the disconnected connector between "X6.3" and
"X6.4", and compare with resistance/outdoor
temperature curve shown on the below.
3. If the value measured differs significantly from the
curve, disconnect wires from the sensor and repeat
the measurement directly on the sensor.
4. Depending on the result, replace cable or the outdoor
temperature sensor.
Check boiler temperature sensor
1. Disconnect cables from boiler temperature sensor A.
2. Measure resistance of the boiler temperature sensor
and compare with resistance/boiler water temperature
curve shown on the below.
3. If the value measured differs significantly, replace the
sensor.
IMPORTANT
As the sensor is in direct contact with the boiler water,
the boiler must be drained before changing the sensor.
Troubleshooting
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