What does the Vaillant F.68 fault code mean?

Your boiler is struggling to keep its flame burning steadily, causing it to shut down for safety.

How much does it cost to fix Vaillant error code F.68?

Typical repair cost for the Vaillant F.68 fault is £120-£350 including labour.

Vaillant F.68 Fault Code: What It Means & How to Fix It

What the manual says

Manufacturer manual

Unstable flame signal

Shared across the range

This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.

What causes this fault?

This fault occurs when the boiler's control system detects that the flame is flickering or dropping out during operation. It is often caused by a worn sensing probe that can no longer 'see' the flame effectively, or a gas valve that isn't providing a steady enough flow of fuel to keep the burner alight.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

Find a Gas Safe engineer

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Related fault codes

F.27View →F.28View →F.29View →

All 170 fault codes on the ecoTEC Plus 635

Seeing a different code? Every code this model can display, in one place.

con d.00 D.000 d.01 d.02 d.04 d.05 d.06 d.07 d.08 d.09 d.10 d.11 d.13 d.14 d.15 d.16 d.17 d.18 d.19 d.20 d.21 d.22 d.23 d.24 d.25 d.27 d.28 d.31 d.33 d.34 d.35 d.36 d.39 d.40 d.41 d.43 d.45 d.47 d.50 d.51 d.58 d.60 d.61 d.62 d.64 d.65 d.66 d.67 d.68 d.69 d.70 F.00 F.0 F.01 F.1 F.10 F.11 F.12 F.13 F.20 F.22 F.23 F.24 F.25 F.27 F.28 F.29 F.32 F.33 F.49 F.61 F.62 F.63 F.64 F.65 F.67 F.70 F.71 F.72 F.73 F.74 F.75 F.76 F.77 F.78 F.83 F.84 F.85 F.86 F.87 F.88 F.89 F.91 F.92 F.97 F22 F70 P.00 P.0 P.01 P.1 P.02 P.2 P.3 P.4 P.5 P.06 P.6 P.07 S.0 S.01 S.1 S.02 S.2 S.03 S.3 S.04 S.4 S.05 S.5 S.06 S.6 S.07 S.7 S.08 S.8 S.10 S.11 S.13 S.14 S.15 S.16 S.17 S.20 S.21 S.22 S.23 S.24 S.25 S.26 S.27 S.28 S.30 S.31 S.32 S.33 S.34 S.36 S.39 S.41 S.42 S.46 S.53 S.54 S.88 S.91 S.96 S.97 S.98 S.99 S.108 S.109 T.02 T.03 T.04 T.05 T.06 T.08

Your boiler is struggling to keep its flame burning steadily, causing it to shut down for safety.

What the manual says

What causes this fault?

Engineer required

Avoid the next call-out bill

Related fault codes

All 170 fault codes on the ecoTEC Plus 635

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