PEX Manifold System - Pros and Cons + Tour

In this video Matt walks you through a manifold system that uses PEX lines for a home run plumbing layout. He also shows you how the water softener integrates as well as reviews the pros and cons of this Viega system.
Gary Klein Article in The Journal of Light Construction

[larrywise]

I have had this very manifold system in my house for over 16 years and LOVE it. I did all the plumbing myself and was very easy to do. It does eliminate the shutoffs at each fixture which in my experience many times need replaced about the time you need to use them so you have to do the whole-house shutoff thing anyway. It was VERY nice to just turn off one 'circuit' and change out a faucet recently when I needed to do that.

[thGenNativeTexan]

For a larger home (or any home really) while the system above is extremely granular (meaning that I can literally turn off cold or hot water at EVERY SINGLE FIXTURE), probably just as useful would be to plumb it like your breaker box, meaning that one "circuit breaker" turns on or off an entire room, such as a bathroom. Probably just as useful as the system above, and eliminates the need for every hot water run to a bathroom needed to evacuate an waiting.

[JasonBrown-edoc]

Installed this in my renovation in northern maine. The house is an old 1930's Victorian style. I am not a plumber at all so pex was a great option. Did the 36 port vega and couldn't be happier.

He is spot on with the pluses with the use of this. It allowed me to work room by room and slowly bring on services. It also allowed me to do a "loose install" until the house is finished and I can finalize the "design" (it's a but if a rat's nest at the moment by design). The ability to cut a single service is a life saver. I moved the location of my water heater to get it closer to the manifold (faster hot water). And had to add a temp spot for washer and dryer.

Cons after 1 year. Hot water delivery can tak a little bit on faucets, showers arent an issue because you generally turn them on and take a minute to get in. Biggest problem was the town pressure was only 40psi... to low. I picked up a grundfos scala2 and cranked it up to 70 to 75 psi (what I'm used to). With the long runs from manifold to faucets the pump does get a workout. I'm sure with a conventional setup it would maintain a bit better, I'm talking only about 5psi flux so first world problems.

My longest runs go about 40 line ft. Again this is an old house so a bit of over the river and through the woods was required. I would suggest if you have the extra $$ get the upanor/weisbro pex A and the the expansion tool. A friend who is doing a new construction uses it and its flexibility is very nice. Pex B is a little more stubborn in tight places.

Overall for a DIY you cant beat the system, a little sharkbite here and some crimps and clamps there and you are happy.

[johnalvitre]

Hello again Matt. I did install one of these on my prior home. I also had an on demand tank installed. The hot water travelled short enough distances that it was minimal loss, or put a water pitcher in the shower to use for plants later. But this in home run setup with an on demand left me continuous hot showers when I needed for guests, or just long enough for my family of two when we were alone. The gain in not heating water all day was more than enough to reduce any cost of water lost in bringing hot water up to the point of use. Also, 1/2" lines going vertical were easier on the pressure variant vs. a wider column of water. No pumps were needed and if you want to add more lines for a shower, add away and have multiple heads running on a second floor. My setup was 36 circuits, no split or shared lines. All stub outs to the cabinet and I tape my exposed tube with duct tape, the metal looking one without logos. It was easy to secure the lines in walls and having zero joints also helped against joint or 90 degree angles causing resistance to pressure. I am a "Handyman" but I do pull permits on my own home and have been appreciated by the electrical or plumbing inspectors. So it can be done by a homeowner who worries about all the work. Great show and thank you for sharing your info with us.

[JasonTaylor]

I put this in my house 8 years ago. The time to fixture was a consideration in my design so for any small fixtures like standard sink faucets, dishwasher, clothes washer, I used the outlet adapter that converts to 3/8" at the mana-bloc. Also, I used 2 - 1/2" colds and 2 - 1/2" hots for the whirlpool tub in conjunction with 3/4" valving so the tub fills very fast. I insulated the pipe from the heater.

[johnandmonicadangelo]

This is a great channel.


I have a home run system very similar to this that I installed. One of the main benefits that we have found is that you do not get the same sudden change in temperature while taking a shower when someone turns on another fixture that you get with other systems. Also, if you are doing the renovation yourself, its very very nice to be able to trial each fixture without turning all of the water off and/or turn off a hot or cold line while working on it.

[treffle]

I feel like after a while, we will find enough information in his video to walk you through how to build a new house from scratch. That was part of the plumbing chapter.

[brucejohnson]

I live in a 1800' 2-story townhouse built in 1985. It was originally built with 3/4" galvanized plumbing throughout. In 1994, due to ongoing leakage problems in the pipes themselves, I made the decision to re plumb the entire house with PEX and a Manablock manifold. That was the BEST decision I ever made. I have been extremely pleased with the system, and find that I get hot water at the fixtures quicker than before. My PEX is 3/8" and I find that completely adequate. I did have one problem being a leak in the manifold itself within the 10 year warranty period. The company replaced the manifold at no charge, and I have not had any problems since then. I recommend it for any application, especially re-piping. My manifold is installed in my attached garage behind my washer, next to my water heater.

[RustyNail]

Matt, one option in Manabloc's system is to go to 3/8" lines for all faucets and lower flow fixtures (depending on code, it could theoretically serve fixtures up to 3.0 gpm). That way, your wait time actually goes down compared to a trunk and branch system. Of course, any large volume fixtures (shower, washing machine, etc) still gets 1/2". I've installed this system in several small multifamily buildings and the occupants love it.

[richardgaudette]

I live here in upstate NY and I am a contractor. I do most of my own work such as plumbing, electrical, sheetrock, trim etc. I did the same on a 2 story home I remolded a few years back. I ran a 1" pecks line from the well holding tank to a large primary water filter then continue with 1'" manifold tee off with 3/4" for electric hot water and all the fixtures in the home with the exceptions of the toilets witch were 1/2". So I had two 1" manifolds one for hot and one for cold with a shut off valves for all the fixtures and on the end of each going into the sub pump hole. So you could shut off the individual fixture and drain the line. Work great! Plenty of pressure in all fixtures!

[WallStreetBeggar]

I've seen this install setup a few times, you can install a recirc to the system anytime. You essentially run your recirc off one of the hot outlets, however, all it's doing is recirculating the feed line. It doesn't really make a huge difference unless your mech room and manifold is farther away.

The ideal manifold install is through Uponor's manifold system. It's sort of a hybrid trunk and branch system. Essentially you install an in wall manifold on your branch line, and your run your trunks through the manifold. I've had my plumbers do it on several builds now, and it cuts down on a lot of fittings in exchange for a lot more 1/2" pipe. This way your 1/2" pipe runs are usually <15' from manifold to the outlet. Usually it makes the biggest difference with hot water, especially with a recirc on your main line because all your branches are short you're essentially draining 10-15' 1/2 at most.

[deadfred]

😩I'm such a novice for not realizing that PEX is actually usable for standard plumbing & not just hydronic heating and cooling systems. What I don't understand, as a novice, is the point of having every single spigot on its own line, even if this is supposed to be a small house. At the same time, that also seems like an excessive amount of spigots for a smaller house. About to look into trunk & branch systems to see what's different. Glad I came across this channel.

[fredaguilasport]

I have been installing this system in all my new construction in texas for more than 12 years

[kameljoe]

Matt there are a few things that one could very well do to improve hot water flow on a large house. Install more water heaters. Many people are switching to tankless under sink for direct on demand hot water.
Manifolds are fine in some applications. They work best if you run your large line to the areas that you need and install a small closet or access panel along with a water heater per bathroom. This means you run cold water main line to master bath and one line to water heater and the rest to fixtures.
My house is going to be a branch design. With 3/4 all thru out and very few of them will be 1/2, most of the half inch is just to make the connection for for very short couple feet runs.
I have a well that delivers 25 GPM at 60psi with a main 3/4 inch line that will at some point be replaced with a 1 inch pex line. I am also going to install commercial 1 inch outdoor faucets along with getting 1 inch garden hose as well.

[christophergruenwald]

I installed this system on my house. One benefit you forgot to mention is greatly reduced fluctuations in pressure. So when you are in the shower and someone is flushing the toilet or running the sink, you water pressure isn’t constantly fluctuating. Plus with zero fittings and long bends there is considerably less resistance within the plumbing. When I did mine, from the meter I ran 2 1 inch pex to the utility room, 1 to the cold side manibloc and 1 to the on demand water heater. My house is a very tall 2 story house with 2 showers on the 2nd story. With only 43psi of city water I can run both showers, the dishwasher and cloths washer with almost no noticeable pressure loss at the showers. It’s very handy when running 4 kids through the shower in the evening while cleaning up after supper and doing the laundry.

[jacktracy]

I have a Pex system in a 2 story 3000 sq’ house. Max HR is @60 ft to the laundry room.

No problems. Normal lag time on the hot water. Manifold in the walk-in attic.

Love it.

[Dirtdabber]

I love the manibloc system I put in myself easy had no issues so far in a new construction I have done myself.

[bitrunner]

i live in central florida and have one of these systems - it's in the garage, and the company that installed it built a box/cabinet around it, so it has two doors that open to get access to the panel - just like having a circuit breaker for your water system. only drawback i have is that i didn't pay extra to insulate the cold water, so in the summer (most of the year) the water in the cold pipes heats up (they run through the attic) so you have to let the water run for the 15-20 sec for the cold water to come through, so opposite of what Matt talks about in the video with hot water. and, as others have mentioned, you don't get pressure drops or temperature changes when someone uses another fixture in the house (like having someone flush the toilet while you're in the show)

[WildWonderfulOffGrid]

Awesome! We are planning on using a PEX manifold for our radiant heated floors on our house build!

[wolfgangunger]

That is called Star Topology! Home runs in electrical and data follow that Star Topology pattern. Thanks Matt for all your videos....I am a construction estimator and I love the new stuff you bring to the table.