Low
S.97 on Vaillant ecoTEC Regular

Your boiler is currently running a brief automatic safety check to confirm its internal water levels before it allows your heating or hot water to start.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

What the manual says

Manufacturer manual

Water pressure sensor check is running, demand (DHW or heating) is blocked

From this model's manual
Verified against the Vaillant Ecotec installation & service manual, page 43.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Wait for the check to complete (usually takes less than 1 minute)If the code persists, check the boiler pressure gauge is between 1 and 1.5 barIf pressure is low, top up the system using the filling loopPress the reset button if the code remains on screen for an extended period

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