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S.02

S.02 — Heating Mode Error: Water Pump Running (EcoTEC Pro / EcoTEC Plus)

Vaillant · Turbomax Plus Boilers

What does S.02 mean?

This code suggests an error related to the water pump operating in heating mode in your EcoTEC Pro / EcoTEC Plus boiler, possibly indicating it's not circulating water effectively or is running when it shouldn't be.

Common Causes

  • Water pump malfunction
  • Incorrect pump operation

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Check your system pressure and top up if it's low.

  2. 2

    Restart the boiler by cycling the power off and on at the mains.

  3. 3

    Ensure all radiator valves are open to allow proper circulation.

  4. 4

    If the error persists, contact a qualified heating engineer to inspect the pump and system.

Browse all codes in this manual (55)
Verified technical data. Last updated: April 2026

Related Faults

F.00F.00 — Flow NTC Cable Defective or Broken (Turbomax Plus)F.00, F.04, F.05, F.10, F.14, F.15F.00, F.04, F.05, F.10, F.14, F.15 — NTC Sensor Fault (Ecomax Pro 828E)F.01F.01 — Feed Temperature Sensor (NTC) Fault or Open Circuit (Turbomax Plus)
Source: Vaillant Turbomax Plus Boilers
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