So I had the heating on this morning and all of a sudden I hear a pop noise and my boiler started making this hissing sound. Sounds like someone has turned a tap on full. So I switched it off and the noise just continued. I can also hear the sound in the radiators as well. Council won't come and fix it till Monday afternoon. I'm just wondering what could be the reason for the noise? It's had me worried/irritated all day. I live in a flat so turning off the water etc not an option.
Presuming this is a hot water boiler: The boiler pressure relief valve is popping off. Pressure has reached the point where the valve opens automatically to protect the boiler from damage do to excess pressure. It is often an indication of a problem with some other boiler component. It should be addressed soon by the landlord, as the popoff is kind of the last like of defense and could result in an expensive repair. When the valve releases, it emits hot water and steam, so stay clear of the boiler. Leave this to the landlord and the professionals he/she hires.
