Dan87
New Member
My oil burner which has a summer-winter hookup is pushing it's DHW to my PEX manifold, which then is traveling through the hot side of the water heater, pushing hot water back out the cold inlet of the water heater, and back into the manifold, thus causing my cold lines at the manifold to get warm/hot. The only cold line that the hot water really travels to next is the boiler cold feed (it's basically creating a loop, and no there is not a recirculater in my system). I've been told I should install a "backflow preventer" on the cold hot water heater feed before the expansion tank (so the expansion tank is in between the back flow preventer and the water heater). That's all well in good, but I've yet to find what I need. I talked to my dad who has done plumbing for 30+ years, and he claims all he has ever used is a spring-loaded check valve in my situation. All of the back flow preventers I'm finding are for boilers and aren't "potable" water rated. Is a spring loaded check valve ok or does a true backflow preventer work better/safer? I feel like what I need is a 3/4" brass or stainless steel, lead free, back flow preventer that is for DHW, but I have yet to find one. If someone knows what I'm looking for, please, let me know! Thanks!
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