PEX can’t be immediately connected to a water heater. Very first lengthen a pipe 18 in. from a water heater and join the PEX on the pipe. PEX offer expands and contracts a lot more than copper, so don’t extend it restricted. Enable it droop just a little among fasteners. https://copperrepipe99764.wikiconversation.com/7057742/a_simple_key_for_replumb_house_unveiled