# Opinions on manabloc system



## Best Darn Sewer

A lot of new neighborhoods here in Houston and surrounding area are advertising that they use the manabloc system. I am no fan of this system due to it is extremely limited if you wish to add fixtures or remodel due to ⅜ pipe being used for most fixture branches or you have to run a completely new line from the box, assuming there's room left. Also, you cannot put a circ pump on the hot water, which is a complaint I hear a lot, because it takes forever to get hot water to far fixtures. 

The answer that people have had for the time it takes to get hot water to the kitchen was a small little 120 VAC hot water tank at the point of use, which is ridiculous. Also, here in Houston, after about 5 or 6 yrs, the valves at the main controls go bad or leak and you have to replace the entire box! 

Not having angle stops and using only the valves at a central location is ok but the lines connect straight to the kitchen and lav faucets so when you want to replace the faucet you sometimes have to find the special gaskets or adaptors or cut the pipe and put on valves. 

Anyhow, my main question is that is this system better than traditional piping or is it just like most things track house new construction builders do which is, "the cheaper and quicker, the better."? Is there something I'm missing? I do profit from the cheap nature of new construction but I hear this system touted as being the new great thing.


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## rjbphd

Best Darn Sewer said:


> A lot of new neighborhoods here in Houston and surrounding area are advertising that they use the manabloc system. I am no fan of this system due to it is extremely limited if you wish to add fixtures or remodel due to ⅜ pipe being used for most fixture branches or you have to run a completely new line from the box, assuming there's room left. Also, you cannot put a circ pump on the hot water, which is a complaint I hear a lot, because it takes forever to get hot water to far fixtures.
> 
> The answer that people have had for the time it takes to get hot water to the kitchen was a small little 120 VAC hot water tank at the point of use, which is ridiculous. Also, here in Houston, after about 5 or 6 yrs, the valves at the main controls go bad or leak and you have to replace the entire box!
> 
> Not having angle stops and using only the valves at a central location is ok but the lines connect straight to the kitchen and lav faucets so when you want to replace the faucet you sometimes have to find the special gaskets or adaptors or cut the pipe and put on valves.
> 
> Anyhow, my main question is that is this system better than traditional piping or is it just like most things track house new construction builders do which is, "the cheaper and quicker, the better."? Is there something I'm missing? I do profit from the cheap nature of new construction but I hear this system touted as being the new great thing.


And how do a lot of people know about this?? That guy, the plumber on 'this Old House' been whoring the product. Can't stand him butchering the hot water heating system ethier.


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## JoshJ

I dislike those things. 

Around here there was one guy who had a love affair with them. Put them in all over. I get lots of calls from people about 10 years later, who are going to reno the bathroom or kitchen, and the valves on the bloc are seized. Literally just replaced some on Friday.

They also seem wasteful for the hot water usage, because there is no recirc possibility, and because you have to run water through ever individual line to get hot water.

The only benefit could be less pressure fluctuation, but as I always tell my customers, if your lines running through the house are sized properly, you won't have that issue with a trunk and branch water supply anyways.

Finally, I don't think it is really any cheaper than doing a traditional water supply system. You burn through a pile of pipe, and up here anyways, the manablocs are not anything near inexpensive.


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## Will

I use them sometimes. They work good once in place, pita to install


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## redbeardplumber

What Josh said.

Do. Not. Do. It.


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## dclarke

I have installed them. Not a fan. Codes here is like 50 max run without a return line for the hot now.....pretty much makes manoblocs worthless and I am fine with that.


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## Best Darn Sewer

Sounds like the consensus is that they aren't worth a sh**. I have wondered since they seem to be popular here now.


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## Plumberman911

I dont like them. Running service I have broke the stems trying to turn the cheap things off. The idea is cool but the funtion sucks. Like you said most times you end up with stops under the sink later so why bother with manobloc.:no:


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## Best Darn Sewer

Sounds like the consensus is that they aren't worth a sh**. I have wondered since they seem to be popular here now.


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## 100 Watt

Had a builder who loved them. He saw them at a trade show and thought they were great. We installed a dozen of them in new builds. He finally had someone complain about time it took to get hot water. He called me wanting a circ line/pump installed. I had to AGAIN explain that you couldn't do it. Needless to say - no more maniblocs for him.

I hate the things. Too much pipe wasted. a Ticking time bomb for unaware home owner. Good luck finding new valves / gaskets in another 10 years


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## plumber101us

pex is used a lot up here but most plumbers shy away from manablocks and make their own manifolds if they want a centrally located shutoff center


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## kiddplum

*opinions on manabloc system*

done a lot of new homes with pex and never used a manabloc
i have seen them installed and then no shut off valves were located at the fixture what a pain that must be for the service plumber
i prefer the valve at the fixture and would use bullet manifolds in the basement


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## wyplumber

Only ever installed one the homeowner had to have it and still loves it. We used the "hot" side for hard water and the "cold" side for soft water code dictates over 50ft gets a recirc here so hot water is all ran like normal biggest waste I have ever seen oh the joys of having the homeowner be the gc


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## The bear

The only thing worst than a manobloc system is a polybutlene manobloc system. A lot of homes that had copper failures where repiped with this garbage. Valves on manobloc never work. No cutoff at fixtures is ridiculous. Junk,Junk,Junk


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## Best Darn Sewer

Haha. I had a customer the other day who was his own GC. His kitchen drain clogs up every few months or so and has been for 3 of the 4 years since he built it. I haven't figured out all the reasons yet but being it's a home warranty comp job it takes a while to approve the additional work. All I know so far is the island sink is auto vented. But the auto vent works. Not code, but its working.


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## redbeardplumber

I walked into this the other day.

So I thought we couldn't do a recirq line in a manabloc system?

Wow!


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## gladerunner

I do a lot of total rehab's meaning all new from street through out house. Mostly 3 or 4 story single family with mechanicals in basement and bathrooms on upper floors. All high end work. I use Mana-bloc's all the time. I don't like the thought of burying fittings. What I do is locate the Mana-bloc in a central location like a 2nd floor closet or laundry room and run a recirc line from hot water feed into Mana-block back to HWH in basement. works fine. Only fittings in walls are the copper stub outs at lavs. and connections @ shower valves. Still pipe tub and showers with copper


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## redbeardplumber

It is still a long way to go to farthest fixture in a lot of applications from mana bloc. I used to put tonnes in, seemed like an ok idea. However 10 years later.... Not so much, people lose there key, the valves break and you have to shut whole system down to make a repair, and on and on....


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