High Lockout
E78 on Baxi EcoBlue Advance

Your boiler has lost its ability to accurately measure water pressure, which prevents it from running safely.

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

Water pressure sensor fault

What causes this fault?

This fault occurs when the boiler's internal computer can no longer read a consistent signal from the water pressure sensor. The most common reason is that the sensor itself has developed an electrical failure or has become blocked with system debris, preventing it from detecting if there is enough water to operate safely.

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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