Boiler leaking water from underneath the casing or pipe connections

Safety first: Switch off power to the boiler. If the leak is significant, turn off the cold water supply to the boiler and the heating flow/return valves if accessible.

User checks:

• Place a tray or towel under the boiler to contain water and prevent damage.
• Look underneath (without removing the combustion cover) to see if water is coming from a pipe joint, PRV discharge pipe, or condensate pipe.
• If water is dripping from the PRV discharge pipe (usually copper pipe to outside), note this for the engineer.

Do not:

• Do not remove the sealed combustion cover.
• Do not attempt to tighten gas or internal water joints inside the boiler.

Professional actions:

• An engineer will identify the leak source, which may require replacing the automatic air vent, PRV, pump seals, or primary heat exchanger, and then repressurising and testing the system.