Wavin Hep2o is the primary solution for central heating systems and hot and cold water services. This is a 15 mm x 19.05 mm appliance valve with hot and cold indicator inserts for Hep2O Push-Fit plumbing. Hep2O is not just designed to perform, it is built to last, which is why it comes with a 50 years guarantee (twice as long as anyone else). The slim and sleek push-fit plumbing fittings work with both plastic and copper pipe and are perfect for a range of hot and cold water and heating applications. It is easy to install and has proven performance.