Best Of

Rehau is far superior IMO.

If you take a two foot length of each one and intentionally keep bending it in the middle, the Uponor will break long before the Rehau.

I’ve also seen demonstrations of several different types/brands tested under pressure and the Uponor blew out before some of the cheaper type B pex.

I was hired to remove a steam heating system from a 3,000 square foot, 2-level apartment in Manhattan a couple years ago and repipe it independently from the rest of the 8-story building’s central steam system. It was, by any measure, a new downfeed steam heating system with two new overhead mains, new decorative radiators and hardware, and steam valve controller. It’s a little different from what you’re asking but I think it qualifies.

Absolutely critical. The vapourstat MUST be set to cutout at no more than 7 OUNCES per square inch (0.42 psig). Differential set at 4 OUNCEES. You should add a low pressure gauge (0 to 3 psig) to verify the pressure settings.

Anything more than that and the system will not work properly, if it works at all.

I don't seem to see any evidence of a Hoffman Differential Loop, and it quite possible that it never had one; only Hoffman Equipped Systems did. Or it may have been removed in some previous "improvement". in any case since neither it nor any other similar device is there, you are entirely dependent on the correct vapourstat settings.

Everything else is secondary at this point. You seem to have main vents in odd spots; Odds are the only vent you need is that big Hoffman, unless someone removed the crossover traps — in which case you probably need more main venting, but we can fix that later.

The oversize boiler isn't going to help, but what's done is done as far as that goes.