What does the Glow-worm 0.5bar fault code mean?

Your boiler has lost water pressure and has shut down to prevent damage, meaning you will not have any heating or hot water until the system is topped up.

How much does it cost to fix Glow-worm error code 0.5bar?

Typical repair cost for the Glow-worm 0.5bar fault is £0-120 including labour.

Can I fix Glow-worm fault code 0.5bar myself?

Locate the filling loop, which is usually a flexible silver hose with two small taps underneath the boiler.

Glow-worm 0.5bar Fault Code: What It Means & How to Fix It

Technical description

Lack of water fault (<0.5b)

What causes this fault?

This fault occurs when the water level inside your central heating system drops below the minimum safe limit. The most common reason is a slow leak from a radiator valve or pipework, but it can also happen if you have recently bled your radiators without topping the system back up.

This fault is frequently seen in autumn when homeowners turn their heating back on for the first time or bleed their radiators to remove air pockets.

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

Search the official register →

Your boiler has lost water pressure and has shut down to prevent damage, meaning you will not have any heating or hot water until the system is topped up.

Technical description

What causes this fault?

Engineer required

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