paulplumb
Hi Brian, you have what is called an unvented cylinder there. The black bit with holes in it is called a tundish. Water is discharging through the tundish beacause there is a fault with the system. Essentially an emergency release has activated. Unvented cylinders can be extremely dangerous so there are a number of safety mechanisms built in to this system. You may need to employ a local plumber or heating engineer to assist you. Make sure they have their G3 unvented ticket. Where abouts in the world are you?
