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F.84

Fault: NTC temp. diff. implausible

Vaillant ecoTEC Pro 28 Combi

Possible cause
Temperature difference is implausible
Measure
Check: Flow/return temperature sensor (correct thermal connection, sensors are inverted).
This code also applies to:
ecoTEC Pro 24 CombiecoTEC Pro 30 Combi
Source: Manufacturer manual (PDF)
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