What does the Vaillant T.04 fault code mean?

Your boiler is struggling to move heated water to your hot water cylinder, which means you may not have any hot water.

How much does it cost to fix Vaillant error code T.04?

Typical repair cost for the Vaillant T.04 fault is £180-£350 including labour.

Vaillant T.04 Fault Code: What It Means & How to Fix It

What the manual says

Manufacturer manual

Cyl. charging pump

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 is unable to detect that water is being successfully moved to heat your hot water cylinder. The most common reason is that the dedicated charging pump has either seized up due to debris or suffered an electrical failure, preventing the transfer of heat. In some cases, a loose wiring connection or a faulty control board means the pump isn't receiving the signal to start.

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.20View →F.24View →S.24View →

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.05 T.06 T.08

Your boiler is struggling to move heated water to your hot water cylinder, which means you may not have any hot water.

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 840

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