High Lockout
Green LED On, Yellow LED On on Vokera Option

Your boiler has lost water pressure and needs to be topped up to function correctly again.

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

Low pressure (Requires 'topping-up')

What causes this fault?

This fault occurs when the water pressure inside your heating system drops below the minimum level required for the boiler to fire up safely. The most common reason is a tiny leak from a radiator valve or joint, though pressure also naturally drops if you have recently bled your radiators to remove air bubbles.

This issue is more frequent in autumn when homeowners turn their heating back on for the first time or bleed their radiators to prepare for winter.

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.

Find a Gas Safe engineer
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