High
04 on Vokera Linea Plus AG

Your boiler has stopped working because the water pressure is too low for it to run safely.

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.

What the manual says

Manufacturer manual

Insufficient water pressure. Check pressure gauge reading, if low restore pressure (see 6.3.4) then re-set as described in code 01. Re-set as described for code 01.

From this model's manual
Verified against the Vokera Linea Plus Ag installation & service manual, page 68.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

What causes this fault?

This fault occurs when the internal water pressure drops below the minimum level required for the boiler to operate safely. The most common reason is a slow leak somewhere in your central heating system, though it can also happen if you have recently bled your radiators and haven't topped the pressure back up.

This fault is frequent in autumn when homeowners turn their heating back on for the first time after summer, often revealing pressure drops that occurred while the system was idle.

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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