Solar pipe insulation for thermal system is an important element to improve the efficiency of any system. It allows maximum heat transfer to your cylinder. Externally it also protects pipework from damage by the elements. Internally it reduces overheating if the airing cupboard or plant room. Furthermore, it protects from burns on potentially hot pipes.
Incorrect solar pipe insulation
Incorrectly installed low temperature (often grey) insulation is likely to melt due to high temperatures from solar panels, so must be replaced.

Non-UV external insulation is often damaged by the sun so breaks down and needs to be replaced.
The wrong insulation can also be a cosy home for insects so then be pecked by birds!