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F.11

Short circuit: Return sensor

Vaillant ecoTEC Pro 28 Combi

Possible cause
Return temperature sensor defective or has short-circuited
Measure
Check: NTC plug, cable harness, housing, PCB, NTC sensor.
This code also applies to:
ecoTEC Pro 24 CombiecoTEC Pro 30 Combi
Source: Manufacturer manual (PDF)
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