What does the Vaillant T.08 fault code mean?

Your boiler is currently completing a routine check of its burner system while it is in the process of starting up.

How much does it cost to fix Vaillant error code T.08?

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

Vaillant T.08 Fault Code: What It Means & How to Fix It

What the manual says

Manufacturer manual

Burner

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 message appears because the internal control board is performing a brief safety verification of the gas burner's functionality during the ignition sequence. It is a completely normal part of the boiler's startup procedure used to ensure the system is operating correctly before it begins heating. This is not a physical failure or a breakdown, but rather a standard status update from the boiler's software.

DIY fix possible

Wait for 2-5 minutes to see if the status code clears automaticallyCheck that your gas supply is active at the meterEnsure your thermostat is calling for heat

Find a Gas Safe engineer

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Related fault codes

S.08View →F.28View →F.29View →

All 170 fault codes on the ecoTEC Plus 840

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.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

Your boiler is currently completing a routine check of its burner system while it is in the process of starting up.

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 840

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