E125 — Water circulation fault

What does E125 mean?

The boiler has detected an issue with water circulation in the primary heating circuit, often indicated by a lack of temperature change after ignition or rapid temperature changes.

• Poor primary water circulation.
• Blocked or jammed pump.
• Air in the heating circuit.
• Closed isolation valves on the heating system.
• Faulty temperature sensors.

Click steps to track your progress.

1. 1

   Press the 'Reset' button on the boiler for 1-3 seconds.

2. 2

   Ensure all heating system valves (e.g., radiator valves, main flow/return valves) are fully open.

3. 3

   Check the system water pressure on the boiler's gauge and re-pressurize if too low.

4. 4

   If the error persists, a qualified technician should check the pump, bleed radiators for air, and inspect for blockages.