3-Loop Stainless Steel Radiant Heat Manifold

I purchased 4 of these (3, 5, 7, & 8 loops) and installed them myself. I am not a plumber, but managed to get them in without too much difficulty. Do be aware that they are large (much bigger then the old INFLOOR units I replaced), but that they seem to be about the same size as other brands with similar function. They also seem to be less expensive due to the stainless steel bodies rather than brass. The units are very solid in construction, and offer excellent bleed / flush ports, and also valves to isolate the unit completely. The also have thermo-wells which is a nice touch, but i noticed that the body of one of mine was loose on the stem so I would not be too dependent upon their accuracy. Do be sure to check the size of your PEX hydronic heat lines (mine are 3.8" so I had to buy those fittings - the default that come with them are 1/2". Also, if you are using 3/8" PEX loops, my plumber (who I had check my work), suggested not to throttle the flow valves back at all as the flow rates are so low that any impedance could cause improper heating. He also pointed out that the manifolds themselves will distribute the flow well due to their large volume so throttling should not be necessary anyway. You should also be sure to use a 1" male brass fitting on each of the inlets and outlets (actually the valve body) as I was unable to get seals with copper fittings (maybe just me - again I am not a plumber, but the brass units worked perfectly first time). You should also be aware that the valve end of the manifold is a bit fiddly when it comes to leak stoppage as you have a sequence of a rubber seal, nylon seal and pipe thread all in just a few inches - but I did get them all to seal and I am sure better plumbers than I will do it without worry. You will need two large crescent wrenches (or a crescent and a pipe wrench) to tighten up this bit if you care about the final position of the valve handle and thermo-well (tough to explain - you will see what I mean when you do it yourself). I did have one fault on the 7 loop unit, and that was a very slow leak around the seal on the flowmeter. PEX Supply replaced the unit without question and the replacement works fine. Overall- good product, I only market the unit down due to the one leaking flow meter (which required removing the whole unit from a very tight opening in a wall cavity in my home), and the unreliable thermo-well.

I have installed 2 of these in my own house for use with an Ultra-Fin system. Both units have leaked chronically at the joint at the ends of the manifolds. I have replaced the gaskets once already but leaks reoccur. When it starts to leak again you have to retighten the joint (more compression on the gasket.) After multiple times of doing this the joint is completely closed (no more compression possible) and then it will eventually again begin to leak with no option but to replace the gasket. I suspect it is a failure of the elastomer of the gasket material. I am about to try silicone o-rings in place of the gaskets and hope this might effect a permanent seal.