Boiler shows E15, may be accompanied by visible water inside the casing or at the base of the boiler.

Safety first: Switch off power and close the cold water and heating isolation valves. Water inside the boiler can damage electrical components.

User-level checks:

• Place a tray or towels under the boiler to contain any dripping water.
• Do not continue to operate the boiler until the leak is identified and repaired.

Technical checks (qualified personnel):

• Remove the front cover and inspect all hydraulic components for signs of leakage (staining, corrosion, wetness).
• Check the plate heat exchanger joints, pump body, automatic air vent, and safety valve outlet.
• Pressurise the system and observe for active leaks.
• Replace the faulty component (e.g. plate heat exchanger, pump, air vent, manifold) and any damaged seals or O-rings.
• Dry and, if necessary, replace any affected electrical parts such as the PCB or wiring.

After repair, refill, vent, and test the boiler for watertightness and correct operation.