Medium
F.080 on Vaillant ecoTEC plus 940 VUI 30/40CS/1-5

Your boiler is struggling to accurately measure the temperature of the water coming into your home, which may result in your hot water not being heated to the correct temperature.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

What the manual says

Manufacturer manual

The cold water inlet temperature sensor in the internal cylinder is defective.

From this model's manual
Verified against the Vaillant/Vaillant Vaillantpro 0020308121 05 Ecotecplus Storage Combi Installation installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

F.081View →

All 125 fault codes on the ecoTEC plus 940 VUI 30/40CS/1-5

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

194F.000F.001F.002F.003F.010F.011F.012F.013F.020F.022F.023F.024F.025F.027F.028F.029F.032F.035F.040F.042F.044F.047F.049F.057F.061F.062F.063F.064F.065F.067F.068F.070F.071F.072F.074F.075F.076F.077F.078F.081F.083F.084F.085F.087F.088F.089F.090F.092F.095F.096F.097F.105F.194F.195F.196F.317F.318F.320F.321F.322F.323F.324F.325F.326F.327F.330F.334F.336F.337F.338F.342F.343F.344F.347F.363F.707F.905I.003I.020I.144L.016L.022L.025L.032L.095L.096L.097L.105L.144L.194L.195L.196L.319L.320L.322L.343N.013N.027N.032N.089N.095N.096N.097N.100N.144N.194N.270N.317N.319N.324N.343P.000P.001P.003P.008P.021T.001T.002T.003T.004T.005T.006T.007

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