What does the Vaillant S.01 fault code mean?

Your boiler is performing a normal startup procedure by clearing out the combustion chamber before it begins heating your home.

How much does it cost to fix Vaillant error code S.01?

Cost varies. Contact a Gas Safe registered engineer for a quote.

Vaillant S.01 Fault Code: What It Means & How to Fix It

What the manual says

Manufacturer manual

Heatingmode:Advancefanoperation

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 is a brief preparatory phase where the boiler's fan spins up to push air through the system and clear any leftover gases from the burner area. It is a necessary safety check to ensure the chamber is fresh and ready for a clean ignition. This is not a malfunction, but rather a standard step in the sequence before the heating starts.

DIY fix possible

This fault may be fixable without an engineer. Check your manual first.

Find a Gas Safe engineer

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Related fault codes

S.02View →S.04View →

All 170 fault codes on the ecoTEC Plus 625

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.68 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.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 performing a normal startup procedure by clearing out the combustion chamber before it begins heating your home.

What the manual says

What causes this fault?

DIY fix possible

Avoid the next call-out bill

Related fault codes

All 170 fault codes on the ecoTEC Plus 625

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