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F.28

F.28 — No Ignition or Ignition Problem (Turbomax Plus / EcoTEC Pro / Plus)

Vaillant · Turbomax Plus Boilers

What does F.28 mean?

The boiler failed to ignite. This could be due to a lack of gas supply, a fault with the ignition components, or, as a common issue, a frozen condensate pipe.

Common Causes

  • Insufficient gas in the system
  • Defective electrode
  • Defective ignition lead
  • Defective electronic ignitor
  • Frozen condensate pipe

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Check if other gas appliances in your home (e.g., gas hob) are working to confirm your gas supply is active.

  2. 2

    Ensure your boiler's condensate pipe, usually a plastic pipe outside, is not frozen. If it is, gently thaw it with warm water.

  3. 3

    Restart the boiler by turning it off and on at the mains.

  4. 4

    If the problem persists, contact a qualified heating engineer to inspect the gas valve and ignition components.

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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