- Reaction score
- Londonderry, New Hampshire
I'm thinking about adding a heat pump water heater in a difficult to plumb location. We happen to have PEX to/from there for an old hot tub heat transfer system that heated the hot tub from the house boiler. We're never going to use that run for it's intended purpose (hot tub is conventional and elsewhere). Does anyone know if the PEX could be flushed and used for the DWH? I've attached a picture but it appears to say 3/4" CTS-WATTS radiant PEX with DIN 4726 oxygen permeability SDR-9 100psi@180F [NSF-pw ASTM F876/877].