Boiler shows E15 and stops heating

Safety first: Isolate power and close the boiler isolation valves if you see water leaking. Place a tray or towels under the boiler to protect property.

• Visual inspection: Remove the front cover and look for any signs of water, staining, or corrosion on the base tray, pump, and pipe joints.
• Check pressure drop: Monitor the system pressure over several hours. A steady drop indicates a leak.
• Do not ignore leaks: Continued operation with leaks can damage the PCB and other components.
• Engineer tasks: Identify and repair or replace the leaking component (e.g., main heat exchanger, automatic air vent, pump), dry the boiler internals, and test for further leaks.