Boiler leaking water from underneath the casing or from pipe connections, with no error code displayed.

Safety first: Isolate electrical power and, if leak is significant, close the boiler's isolation valves and the cold water inlet. Water and electricity are a dangerous combination.

• Identify leak source (visual): Remove the lower cover (if user-accessible) and use a torch to see where water is forming. Do not disturb internal components.
• Check pressure gauge: If pressure is dropping, avoid topping up repeatedly as this can worsen leaks.
• PRV discharge pipe: If water is dripping from the copper safety discharge pipe outside, the pressure relief valve may be passing due to high pressure or a failed expansion vessel.
• Call an engineer: Internal leaks usually require replacement of seals, pump, PRV, or even the primary heat exchanger. The engineer will also check for corrosion and rectify the root cause (e.g., overpressure, inhibitor levels).