What does the Vaillant F.00 fault code mean?

Your boiler has stopped working because it cannot communicate with the sensor that monitors the temperature of the water leaving the unit.

How much does it cost to fix Vaillant error code F.00?

Typical repair cost for the Vaillant F.00 fault is £90-160 including labour.

Vaillant F.00 Fault Code: What It Means & How to Fix It

What the manual says

Manufacturer manual

Flow temperature sensor interruption

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 main control board loses the electrical signal from the sensor that monitors the heat of the water leaving the unit. It is usually caused by the sensor itself failing due to age, or damage to the internal wiring that prevents information from reaching the central computer.

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.01View →F.10View →F.11View →

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.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 T.08

Your boiler has stopped working because it cannot communicate with the sensor that monitors the temperature of the water leaving the unit.

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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