High Lockout
F01 on Ideal Logic Max System

Your boiler has lost water pressure, which prevents it from firing up to provide heating or hot water.

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

Boiler has a fault for a specific error.

What causes this fault?

This fault occurs when the water pressure inside your heating system drops below a safe operating level, causing the boiler to shut down to prevent damage. The most common reasons for this are a leak somewhere in your radiator network or the pressure naturally dropping over time, especially after you have bled your radiators.

This fault is more common in autumn and winter when homeowners turn their heating back on after a long break and notice leaks from valves or joints.

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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