Sometimes peace of mind is worth a few extra bucks and a little sweat.
I’m totally with you on this. Tried PEX once, thinking it’d be fine for a solar water setup—regretted it after seeing how stiff and weird it got near the collector after just one summer. Ended up swapping in copper anyway. Not worth the gamble, especially when leaks mean way more hassle down the line.
Copper’s a pain to work with, but honestly, it’s saved me more headaches than I can count. I get the appeal of PEX—cheaper, easier to snake through tight spots—but once you factor in the heat from a solar setup, it just doesn’t hold up. Had a neighbor who tried to “save” by using PEX for his collector lines… ended up with a mess and a flooded crawlspace. Sometimes the old-school way really is best, even if your wallet complains at first.
I’m in the middle of figuring this out for my own place, and I keep going back and forth between copper and PEX. I get the “old-school is best” argument—my dad swears by copper, and he’s not wrong about durability. But man, after trying to bend a few lengths myself, I started to see why people love PEX. That said, the idea of melted pipes under my house isn’t exactly appealing… Maybe there’s a happy medium? Like, copper for the really hot bits, PEX everywhere else? Still learning as I go.
Honestly, I get where you’re coming from. I wrestled with the same debate when I redid my bathroom last year. Copper’s tough as nails, but man, it’s a pain to work with unless you’ve got all the right tools (and patience). PEX is just so much easier to snake through tight spots. I ended up running copper from the solar heater to the manifold—figured that’s where the hottest water would be—then switched to PEX for the rest. Haven’t had any issues so far, and it made install way less stressful. If you’re worried about heat, just check the PEX rating and keep it away from direct sunlight or anything that gets crazy hot.
I see the logic in using copper for the hot side and PEX everywhere else, especially if you’re dealing with solar-heated water. Still, I keep circling back to the long-term cost and maintenance side of things. That’s where I get a little hesitant about mixing materials unless it’s absolutely necessary.
You mentioned:
“Copper’s tough as nails, but man, it’s a pain to work with unless you’ve got all the right tools (and patience). PEX is just so much easier to snake through tight spots.”
That’s definitely true—PEX is a breeze compared to copper, no argument there. But I’ve read a few stories (maybe rare, but still) about PEX getting brittle or developing leaks over time, especially if it’s ever exposed to UV or higher temps than it’s rated for. Even with the right ratings, some brands seem to hold up better than others, and it’s tough to know what you’re really getting unless you dig into the specs or pay extra for the top-shelf stuff.
When I did my own setup, I actually went with CPVC for the runs closest to the solar collector. It’s not as “classic” as copper, but it handles heat decently and is a lot easier to cut and glue than sweating copper joints. Plus, the fittings are cheap and you don’t need any special tools. After that, I transitioned to PEX for the longer runs inside the house where temps drop off. No issues so far, and it kept my costs down.
One thing I’d flag—if you’re on a tight budget, copper prices can be wild lately. Even short runs can add up fast. And if you ever have to do repairs, tracking down pinhole leaks in copper is a pain compared to just swapping out a section of PEX or CPVC.
I guess it comes down to how much heat you expect at the manifold and whether you want to future-proof for repairs or upgrades. If you’re careful with your install and stick to the right ratings, PEX can work, but I wouldn’t write off CPVC as an option either. Sometimes the “middle ground” solutions don’t get enough love.
