Low
S.97 on Vaillant ecoTEC Plus 615

Your boiler is currently performing an internal health check on its sensors and has temporarily paused heating and hot water to ensure everything is functioning safely.

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.

Technical description

Automatic test programme: Water pressure sensor, heating and hot water request blocked.

DIY fix possible

Wait for the boiler to complete its automatic sensor testMonitor the display to see if it clears after a few minutesIf the code persists, try resetting the boilerEnsure your system pressure is topped up to between 1 and 1.5 bar

Find a Gas Safe engineer
Search the official register →

Related fault codes

F.22View →F.73View →F.74View →

Related guides you might find useful

No hot water but heating works

Almost always a stuck diverter valve on combis.

Read →

Boiler keeps losing pressure

Six most common causes of dropping pressure.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →