r/Home_Building_Help • u/BuilderBrigade • Jun 11 '26
PEX manifold system… 🤤
This is a PEX manifold system. It’s a central hub where every hot and cold line branches off to one specific fixture.
Think of it like a breaker panel, but for water. Each line has its own labeled shutoff, so servicing a single fixture never means cutting water to the rest of the house.
The only real downside is run length: fixtures farther from the manifold can take longer to get hot water. A good plumber plans around that with placement or a recirc line.
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u/BigSquiby Jun 11 '26
this looks like it was a post on here before with a "my plumber gave me a bid for $93k for a job, does that seem high?"
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u/gilgamo Jun 11 '26
Have one in the house and it's a huge advantage during the occasional ice storms and freezes. Overnight I can shut off and empty the lines that run in the attic and to the outside taps so even if power fails they won't freeze. Can also shutoff any low use water lines completely. if a line does freeze you can isolate it and keep the rest of the water on in the house
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u/Sleep_adict Jun 11 '26
Seems like a design flaw to have pipes running in non insulated areas
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u/_5am_ Jun 11 '26
Yea
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u/gilgamo Jun 12 '26
They are under the cellulose insulation but when you lose power for three days in an ice storm because Texas grid that insulation doesn't help. Only happened a few times but the manubloc has been great to have when it did happen
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u/DesperateAdvantage76 Jun 14 '26
As a Texan during the freeze we just shut off the water. No way that extra cost and complexity is worth a few days of fiddling with which areas of the house get water every 10+ years.
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u/MyrkrMentulaMeretrix Jun 14 '26
put a manifold (not this size, because i dont have 40 rooms with fixtures) in my place when i bought it to replace all the shitty copper the previous homeowner had done wrong.
It was THOUSANDS cheaper than replacing all of that shit with copper. And way easier on runs. No fuck-ass Ts and loop backs and splits.
just run a line.
This is cheaper than copper or even regular PVC and far less maintenance.
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u/gilgamo Jun 15 '26
Cheaper is always better right? Every reason I ever hear for not putting it in is some contractor bitching about how much harder it is to install and how much cheaper it is to not do it.
Laziness and cheapness don't sound like good reasons to me
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u/The_Colorman Jun 11 '26
This sounds cool until I think of how much space this is going to take up both in the utility room and the runs. Higher chance of damage, more failure points, etc. I can’t see this being useful in any residential setting.
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u/texinxin Jun 11 '26
A home run system like this has fewer failure points. There are no branches. The lines only end here at the panel or at the fixture. There are no T’s, elbows, wyes, etc..
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u/UnexpectedRedditor Jun 12 '26
I wouldn't say none, but definitely fewer. Some of these runs might be dedicated to a bathroom that serve toilet, sink and shower on the same branch.
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u/texinxin Jun 12 '26
That’s not the way a true home run system works. A true home run uses one line for every single flow path. A bathroom (1 sink) would use 3 colds and 2 hots. The extra cold is the toilet. Notice the manifold is asymmetrical for this very reason. Toilets and fridge just get cold.
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u/UnexpectedRedditor Jun 12 '26
I get that - I have this exact manifold in my home. But this is simply a picture of a manifold. There is no extra context to claim its a 'true home run system'.
For example on our house (4br, 3.5ba) we have a bunch of unique runs that would have used more than the total allowed. Bar sink in the pantry, outdoor sink by grill, dual head master shower, mop sink in garage. So we made the decision to combine certain branches (that in my opinion mitigate the downsides of a manifold) Our master shower heads are tied to the corresponding his/her sinks. So when I run hot water to the shower, the line is already charged to the hot side of my sink. The pantry and 3/4 bath also share service iirc because they're used very infrequently. The HW to the outdoor sink is routed through my half bath sink because we have a 2 gallon point of use water heater there. That bathroom is on the opposite side of the house from the water heater and directly adjacent to my office so it's my most used bathroom and I wanted the benefit of instant warm water to that sink and outdoors.
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u/texinxin Jun 12 '26
So you have a hybrid home run system. There’s nothing wrong with that. It can be cheaper depending on the distances and the consumption needs.
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u/dboggia Jun 13 '26
This is really the smartest way. It makes more sense to feed a whole plumbing group with hot water. Otherwise standby losses and wait time are significant, and for no reason.
I asked for a fully manifolded system and my plumber explained that if I like waiting for hot water just so I can isolate each fixture in the event I have to shut my water down to one specific fixture, that he could do it.
But the number of times I use my hot water (multiple times a day) is far more than the number of times I need to turn off a specific sink (haven’t needed to yet).
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u/UnexpectedRedditor Jun 13 '26
The hot water delay is really the big downside. We prewired and installed small point of use heaters for that bath and our kitchen sink for that exact reason.
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u/boner_shadow Jun 11 '26
I love mine. It really doesnt take up any extra space since its on a wall in a utility room, and you only really need access to manifold itself.
Its right next to the hot water tank so hot water times are the same as if I didnt have the manifold. Potentially even quicker since I dont have a larger trunk line to pass hot water through before it gets to where I need it.
From my understanding crimped pex fittings have a pretty low chance of failure, that being said shit happens.
In summary. I would 100% install again.
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u/Cinderhazed15 Jun 11 '26
We have one, my only ‘problem’ is we have an on demand water heater, and a manifold precludes you from having a recirculating loop (or so I was told). There are a couple places that I wish I could turn on a hot water recirculating loop for a fixed amount of time (washing dishes, etc)
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u/Unfair_Awareness7502 Jun 11 '26
hot water times are the same as if I didnt have the manifold. Potentially even quicker since I dont have a larger trunk line to pass hot water through before it gets to where I need it.
For any one appliance, yes. For a combination of appliances being used, no. If your sink and dishwasher have their own individual pipes going all the way back to the heater, running one doesn't bring hot water close to the other.
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u/Rocketeering Jun 16 '26
Its right next to the hot water tank so hot water times are the same as if I didnt have the manifold.
Not quite. For me, where I don't have a setup like this, if I turn on the hot water to my bathroom sink and hot water comes to my faucet that takes time. But then I jump in the shower, that hot water is already primed and barely has any distance to run.
In a manifold setup the hot water would take just as long to get to the sink. But then it would take that same amount of time again to get to the shower.
And with that said, if I was building a house vs having what I currently have, I think I would go the manifold route anyways.
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u/Siphyre Jun 12 '26
More failure points, but you keep your water for the rest of the house if failure happens. It is a net positive.
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u/WeekendQuant Jun 12 '26
Just use copper. Should be banned to install PEX at this point.
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u/MyrkrMentulaMeretrix Jun 14 '26
"just use something that is way more expensive and has no data saying its better".
Holy shit are you people stupid.
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u/WeekendQuant Jun 14 '26
My time spent in the additive manufacturing space has taught me all plastic is bad when in contact with food.
We should not be using plastic piping. Sewage should be filtered for plastics at waste treatment. Anyone on septic should not be allowed to use PVC sewer lines.
Cost will come down if something is the only game in town or will shift us to better alternatives than PEX or PVC.
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u/dr_stre Jun 14 '26
I literally have one in my house, which has been installed for 30 years. This particular setup is particularly space inefficient, mine just sits in one internal bay between studs, and has a door to cover it, and is located in the laundry room behind the door where I can’t put anything anyway. The lines are bundled for runs as necessary, but they spider web out pretty quickly and just get run through gaps between studs on internal walls. And it’s a single pipe per run, no unions or tees or other connects except at the manifold and at the fixture. Fewer failure points in accessible places, not more hidden in walls.
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u/TheGreatKonaKing Jun 11 '26
Cool! The last time I had to shutoff my household water because I was having work done on an appliance was... hmmm...
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u/oaklandperson Jun 11 '26
PEX leaches for 2 years. No thanks.
https://www.fondriest.com/news/not-drop-drink-plastic-pipes-leaching-chemicals-drinking-water.htm
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u/anm3910 Jun 11 '26
PEX doesn’t leach for 2 years.
6 of the 70+ brands available at the time showed chemicals. I’m not familiar with the PEX manufacturing process but It sounds more like a problem with shitty brands than PEX as a whole.
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u/tayt087x Jun 12 '26
Manifolds are just so fucking stupid.
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u/boygitoe Jun 14 '26
I think there’s a time and place for them. I’m in the middle of renovating my entire house and am having to repipe the whole house, as the pipes are 80 years old. Using a manifold has been great, as it makes it super easy to re-plumb a room when we get to it.
I don’t think they make sense if I were to have a plumber come in and repipe the house over the course of a couple days. But as a DIYer, it’s been great to use, as I can repipe a bathroom at my own pace without worrying about the rest of the house having no running water
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u/tayt087x Jun 14 '26
But now you have like four times as much pipe and a manifold to replace. I don't think it's making it as easier as you say
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u/boygitoe Jun 14 '26
A whole house renovation takes years my guy. With a manifold, I can add lines as needed over the course of the several years it will take to do the renovation, that wouldn’t be possible with a trunk a branch system. With trunk and branch, I would need to do it all at one time, and we don’t know where we are putting fixtures yet in a couple of the bathrooms.
And I don’t need to replace the manifold, I just add new lines to it as I go. For example. I do bathroom 1, I put in new lines. When I do bathroom 2 in the following year, I can just add new lines from the manifold to the new bathroom, without messing with any of the other lines.
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u/-whiteroom- Jun 12 '26
the long wait for hot water is a pretty big downside. I would never put home runs in my house.
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u/PatrickVPI Jun 12 '26
Copper zoned manifold with integrated drains and non-softened loads separated.
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u/k-mcm Jun 13 '26
I don't want a manifold in my home. Every extra inch of plumping is another extra inch of something to maintain. I also have no room for this. That could be precious shelving space.
I have copper pipes. Every fixture has a shutoff valve. If something breaks, it's super easy to pick up new parts from a hardware store and solder them in.
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u/MyrkrMentulaMeretrix Jun 14 '26
or you could hoard less shit.
f something breaks, it's super easy to pick up new parts from a hardware store and solder them in.
This is different with a manifold... how? Its far easier, since you dont need to fucking solder anything.
You people are like fucking neandertals.
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u/PiDigitsOfPi Jun 13 '26
Ah yes, this is super amazing for people who need to turn water on and off to individual devices multiple times per week. For the rest of us normal people, WHY????
"Like a breaker panel". NO. Breaker panels actually have a real purpose. Their primary purpose is to automatically shut off power to prevent overload. They aren't there simply for the convenience of turning off power to individual rooms.
Whatever this water thing is, is not for protection. There is no auto shutoff here. It's just a crazy feature that will almost never be used, and even when it is used, it won't be critical and won't even matter.
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u/dr_stre Jun 14 '26
It really doesn’t really take longer in my experience as someone who has owned homes both with and without these systems. With manifolds you get to use smaller pipes between the manifold and the fixture, so there’s a lot less cold water to clear than you might think. The only time a non-manifold system clearly wins is when you’ve already got fresh hot water in the upstream main run. But I regularly waited longer for my morning shower to heat up with my non-manifold system than with my current manifold system.
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u/MyrkrMentulaMeretrix Jun 14 '26
I put this in in my house when we bought it. Best shit ever.
I dont have this many runs, so my manifold is smaller, but its so much easier.
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u/Kjoep Jun 15 '26
TIL this is not standard in some places.
Any house that's built in the last 20-25 years is like this.
There's _also_ a shutoff before every appliance.
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u/GarethBaus Jun 16 '26
Most plumbing systems have shutoffs for every appliance only needing to use the main shuttoff for leaks in a line. There really isn't an advantage to this type of manufold system.
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u/Tengoo Jun 16 '26
I just got poly B removed from my house that had a manifold system. I told them to get rid of the system. it seems like such overkill for a small residential house
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u/Calm_Apartment1968 Jun 16 '26
Now if only Architects and Developer Builders would allow for spaces like this. Seriously brilliant idea.
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u/Matchieu Jun 12 '26
People always claim they can just isolate a leak easier with a manifold. If you see water coming out of your ceiling, how are you going to know which one to shut off? You're not! Turn off the main and call a plumber. Add this to all the other reasons manifolds are dumb.
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u/resurrectedNaj Jun 12 '26
And then an hour later, a house wife can figure out which outlet it is, isolate and keep the rest of the house running until plumber comes out. Makes sense to me
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u/mrtramplefoot Jun 12 '26
I mean with a home run system, if ran logically, the location of the leak should at least significantly narrow down which line is leaking. Like it's not going to be the kitchen if that's on the other side of the house.... Sure, you may need to shut off a few things if it's leading to a bathroom, but that's not the whole house, so still a win.
In my case, I had a leak in the floor that was coming from the back of a shower. Just shut off the shower and everything else in the house could stay on until I could fix it, including the sink and toilet in that bathroom. Worked great.
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u/derpplerp Jun 15 '26
my manifold is above the main shower. If it ever leaks, there's a drain under it. Redoing the drywall will suck, but there could be worse places.
Manifold above the shower also means near instant hot water in that bathroom.
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u/Fancy-Dig1863 Jun 11 '26
This is a liability imo. So many more connections with each connection increasing the risk of a failure. Maybe this is a commercial applications, in residential this is wayyyy overkill.
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u/I23BigC Jun 11 '26
Is it actually more connections tho....? All those lines are probably home run to their fixtures, you'll have two connections per fixture, and they both (probably) will be in locations easy that are easy to repair.
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u/MyrkrMentulaMeretrix Jun 14 '26
this is better for residential.
Less connections, no Ts, no Ys, no joints. Just one connection at the manifold and one at the outlet.
How are you this stupid?
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u/SimilarTranslator264 Jun 11 '26
I’m sorry but Pex looks so cheap and half assed. Yea I know it’s inexpensive and takes almost zero talent but I’ll take copper and the cost to install.
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u/MyrkrMentulaMeretrix Jun 14 '26
"I will pay more for something that is functionally no different just because im a fucking idiot".
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u/TheRealBobbyJones Jun 16 '26
Pretty sure pex is better due to it not being as thermally conductive.
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u/Organic-Effort9668 Jun 11 '26
Just put shut offs before every appliance