High
F.90 on Vaillant ecoTEC exclusive

Your boiler has lost the digital connection to its hot water storage tank, preventing the two units from communicating properly.

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.

Technical description

Fault:Communication CheckthecableharnessfromtheproducttotheactoSTORmodule (PEBus). IftheproductistobeoperatedwithoutanactoSTORmodule,set D.092=0.

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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