A1 — Water leak or pump dry run

What does A1 mean?

The boiler has detected a water leak, or the pump is running dry or with air in the system. This can lead to pump damage if not addressed.

• Water leak within the boiler or system.
• Boiler pump running dry or seizing.
• Insufficient system pressure.
• Air present in the pump or system.

Click steps to track your progress.

1. 1

   Check for any visible water leaks around the boiler and pipework.

2. 2

   Ensure the system pressure is at the recommended level, and top up if needed.

3. 3

   Reset the boiler according to your user manual.

4. 4

   If the issue persists, contact a Gas Safe registered engineer to check the pump and system.