High
Connection on Vaillant ecoTEC plus 612 R1 VU GB 126/3-5

Your boiler's controls have lost their connection, meaning the screen cannot talk to the internal computer to tell the boiler how to heat your home.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

NocommunicationbetweenthePCB andtheuserinterface | Electronicsdefective

From this model's manual
Verified against the Vaillant/Vaillant Ecotec Plus Pro 839592 05 2006 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 is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

F.70View →F.71View →F.83View →

All 135 fault codes on the ecoTEC plus 612 R1 VU GB 126/3-5

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

3596conD,11D.0D.1D.2D.3D.4D.5D.7D.8D.9D.10D.12D.13D.17D.18D.20D.22D.23D.25D.27D.28D.30D.33D.34D.35D.40D.41D.44D.47D.50D.51D.60D.61D.64D.65D.67D.68D.69D.70D.71D.72D.75D.76D.77D.78D.80D.81D.82D.83D.84D.90D.91D.93D.96D.97F.0F.1F.10F.11F.13F.20F.22F.23F.24F.25F.27F.28F.29F.32F.49F.61F.62F.63F.64F.65F.67F.70F.71F.72F.73F.74F.75F.76F.77F.78F70P.0P.1P.2P.3P.4P.5P.6S. 2S. 5S.0S.1S.3S.4S.6S.7S.8S.10S.11S.13S.14S.15S.16S.17S.20S.21S.22S.23S.24S.25S.26S.27S.28S.30S.31S.32S.34S.36S.41S.42S.52S.53S.54S.96S.97S.98

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