hi
As shown in the photo, there is some yellow powdery residue around the valve of one of the central heating copper pipes in the airing cupboard. It has been there for many years and so far there is no leak (it’s dry). Could someone tell me what it is and do I need to do anything about it?
Many thanks.
As shown in the photo, there is some yellow powdery residue around the valve of one of the central heating copper pipes in the airing cupboard. It has been there for many years and so far there is no leak (it’s dry). Could someone tell me what it is and do I need to do anything about it?
Many thanks.