Fault Codes / Vaillant / F.519

flexoTHERM/aroTHERM — Sensor fault: return flow temperature sensor — faulty or incorrectly connected to the main PCB. NOT the high-pressure sensor (that's F.546).

Possible causes

• Sensor not connected or input shorted.
• Wiring harness faulty.

Check steps

• Check sensor (with manifold), replace if needed.
• Check/replace wiring harness.

Affected parts

• Hochdrucksensor
• Kabelbaum

Safety note

Source: Vaillant resmi servis kılavuzu — DÜZELTİLDİ: Vaillant aroTHERM VWL ../2 A 230 V Series — Installation Instructions, ManualsLib, page 38 (E — Overview of Fault Codes table): "F.519 — Sensor fault: Return temperature — Sensor is faulty or incorrectly connected to the main PCB." Corroborated by independent web search results r…

Reviewed by Anıl Güzeldemir — in the refrigeration machine room since 2006, developer of Enthalio.

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