What does the Vaillant F.318 fault code mean?

Your boiler is struggling to switch between heating your radiators and heating your hot water because a mechanical valve responsible for directing the water flow has become stuck.

How much does it cost to fix Vaillant error code F.318?

Typical repair cost for the Vaillant F.318 fault is £150-250 including labour.

Vaillant F.318 Fault Code: What It Means & How to Fix It

What the manual says

Manufacturer manual

The 3-port motorised valve does not move.

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.

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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Boiler cover options

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All 172 fault codes on the Turbomax 242/282 1E

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

Burner lock out indicator F.000 F.001 F.002 F.003 F.010 F.011 F.012 F.013 F.020 F.022 F.023 F.024 F.025 F.027 F.028 F.029 F.032 F.035 F.040 F.042 F.044 F.047 F.049 F.057 F.061 F.062 F.063 F.064 F.065 F.067 F.068 F.070 F.071 F.072 F.074 F.075 F.076 F.077 F.078 F.080 F.081 F.083 F.084 F.085 F.087 F.088 F.089 F.090 F.092 F.095 F.096 F.097 F.105 F.194 F.195 F.196 F.317 F.320 F.321 F.322 F.323 F.324 F.325 F.326 F.327 F.330 F.334 F.336 F.337 F.338 F.342 F.343 F.344 F.347 F.363 F.707 F.905 Fan operation indicator Flame indicator Hot water demand indicator I.003 I.020 I.144 Ignition indicator L.016 L.022 L.025 L.032 L.095 L.096 L.097 L.105 L.144 L.194 L.195 L.196 L.319 L.320 L.322 L.343 N.013 N.027 N.032 N.089 N.095 N.096 N.097 N.100 N.144 N.194 N.270 N.317 N.319 N.324 N.343 Power on indicator S.000 S.001 S.002 S.003 S.004 S.005 S.006 S.007 S.008 S.009 S.010 S.011 S.012 S.013 S.014 S.015 S.016 S.017 S.019 S.020 S.021 S.022 S.023 S.024 S.025 S.026 S.027 S.028 S.029 S.030 S.031 S.032 S.034 S.039 S.041 S.042 S.054 S.057 S.059 S.088 S.091 S.092 S.093 S.096 S.097 S.098 S.109 S.175 S.199 S.326 S.328 S.335 S.341 S.599

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Your boiler is struggling to switch between heating your radiators and heating your hot water because a mechanical valve responsible for directing the water flow has become stuck.

What the manual says

Engineer required

Avoid the next call-out bill

All 172 fault codes on the Turbomax 242/282 1E

Related guides you might find useful

No hot water but heating works

Radiators cold at the bottom

Yellow or orange flame — CO safety

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