PEX-in final planning need advice
Hello All,
Now that I got the okay from my local Building Offical to use PEX in the repiping of my house I’m working out a plan and wanted to run it by ya’ll.
Yes I’ve read a ton of threads here about PEX based on that…
Loosely: Want to use manabloc manifold with Wirsbro system.
I’ve got 2 full baths, a kitchenette, a laundry area within about 10′ of the tankless hot water heater. This setup seems like a natural for a manifolded home-run system. The main kitchen is ~25′ from the water heater-this will have 2 sinks, icemaker, DW, maybe a built-in coffee machine if I hit the lottery….
Plan is to put the manabloc right next to my Rinnai tankless WH.
I’ve got a 1″ main line that I will bring right to the area and split it into 3/4″ lines one feeding the cold side of the WH and one feeding the cold side of the manifold-then of course a 3/4″ from the WH to the hot side of the manifold.
Going to use 3/8″ lines to everything except the ‘high use’ items which are the main kitchen sink, the hose bibs, the showers-tubs. High use items will get 1/2″ Does that sound right?
So I’ll be using a ton of 3/8″ slightly less 1/2″ and hardly any 3/4″.
Now for a couple of questions-
- I’ve looked online at the manabloc manifolds but I can’t tell if its possible to run 1/2″ and 3/8″ lines from the same manifold? At pexsupply.com it would appear you only have the choice of one or the other?
- Why does the 3/8″ expander head not come standard with the expander tool? What kind of sense does that make?
- There seems to be weird rules for spacing the manifolds away from WH. The Rinnai only needs an 1″ clearance to combustibles and the double walled direct vent exaust only requires a couple more I think. I’m not going to space the PEX 18″ away from this which is a spec that I believe I’ve seen.
- Any usefull things to use like I’ve seen laundry boxes, icemaker boxes, ?
Any useful advice would be greatly appreciated. I’m not looking to do this tomorrow but I’m hoping to get certified on the Wirsbro system and then either buy the parts locally or order them from PEXSUPPLY.com
Daniel Neumansky
Restoring our second Victorian home this time in Alamdea CA. Check out the blog http://www.chezneumansky.blogspot.com/
Oakland CA
Crazy Homeowner-Victorian Restorer
Replies
As you know, 3/8 will hold less cold water when you want hot. You might want to compare the flow with your taps using 3/8" and 1/2". Since PEX and fittings are cheap, you can try out the 3/8 on your tub to see if it really makes a difference. It might not, or it might be soo little that having the faster hot water is worth more to you.
Just a thought.
Tu stultus es
Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
I plumbed our house entirely with pex. I used the big manifolds Manablock, I think> because there are so many runs. I used two of them-can't remember how many runs, though. I used the red and blue tubing because it was easy to get, and I just didn't think the brand of tubing was too important. I could use both 3/8 and 1/2 tubing with the manifold, simply by using different fittings to attach. Quite easy. I too used 1/2 to big things, tub,shower, dishwasher, etc. 3/8 to faucets and such. I didn't want puny water flows in the showers. The manifolds are located in the basement, and close to the bathrooms, and directly under the kitchen, so it takes only seconds to get hot water. I also used copper to stub out, as I feel its easier to work with. No soldering though, used the L-shaped stubouts.
Stef
You can run 1/2 and 3/8 from the manabloc, even if you have to run a short piece of 1/2 before reducing to 3/8. Don't know specs of manabloc, but some manufacturers make manifolds with a mixture of both sizes.
With a tankless heater, I can't think why there should be any real concern for distances from the heater to PEX, since the heated water will not be continuous, and will not be excessively hot. Some of the rules the PEX manufacturers adopted in the beginning were simply tossed in there to appease local building officials who had to be placated in order get approvals, so that's why some the rules seem like overkill.
A nice thing at the kitchen sink is to install a large activated charcoal filter unit under the sink to supply a drinking water faucet. They're about as big as a large Thermos, and the filter cartridges are cheap and last for about a year for drinking water. They remove chlorine and organic chemicals. I put one in about 2 yrs ago, and it has saved $ in bottled water.
Ditto on the water filter; I love our $11 drinking water cartridges. With the home run, you can put the filter next to the manifold if it's more convenient.
Thats true a filer at the manifold would be easy enough. But why do I need one really? I'm on city water and it tastes fine to me?
Daniel Neumansky
Restoring our second Victorian home this time in Alamdea CA. Check out the blog http://www.chezneumansky.blogspot.com/
Oakland CA
Crazy Homeowner-Victorian Restorer
It's true that you probably don't need one -- I haven't tried Alameda water in a while. But if you have, er, other household members who insist on filtered water, this is the cheapest and most convenient method. We get only a slight improvement in taste on Hetch Hetchy water; the filter removes the chloramines and adds a bit of limestone which keeps the water from tasting totally flat. We also occasionally go through periods of chlorination for whatever reason.You basically don't have to plan for this; it's easy enough to fit in later.
i would insulate all my hot water lines
I missed something... YOU GOT THE OK!?! HOW?
Tu stultus es
Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
Pulled the pregnancy sympathy card! That and he really didn't have a good reason to make me wait till August so I just wheedled him down.
Daniel Neumansky
Restoring our second Victorian home this time in Alamdea CA. Check out the blog http://www.chezneumansky.blogspot.com/
Oakland CA
Crazy Homeowner-Victorian Restorer
Score one for the annoying homeowner!
Tu stultus esRebuilding my home in Cypress, CAAlso a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
I'd like to call it politely persistant thank-you-very-much
Daniel Neumansky
Restoring our second Victorian home this time in Alamdea CA. Check out the blog http://www.chezneumansky.blogspot.com/
Oakland CA
Crazy Homeowner-Victorian Restorer
Is that what you call it when you plant 6 fake pipe bombs and tell them you planted 9? Man, that really gets under their skin.
Tu stultus esRebuilding my home in Cypress, CAAlso a CRX fanatic!
Look, just send me to my drawer. This whole talking-to-you thing is like double punishment.
Why get certified? The manibloc is not certified for wirsbo. Wrong barb style on the manifold.
I'm thinking that if you try it your BI will nail you to the wall.
I just plumbed my entire house with Uponor(wirsbo) PEX and manifolds."Manibloc" is Vanguard - not the same as Uponor.I suggest you download the Uponor PEX catalog from their website. I used a couple discontinued manifolds for my house and I think the new offerings are a modular style valved and infinitely customizable and probably more expensive option. You can probably still find the old manifolds in stock, I've seen then on eBay quite oftenI would add a whole house sediment filter on your 1" line, then I would also feed the hot water heater with 1" rather than 3/4". Then again my house is overkill on plumbing and I am on a private well and not metered city water.I used mostly 1/2" home-runs for the baths and the kitchen/utility is a 3/4" feeder with 1/2" lines to each fixture because it was on the other end of the house. Might have to wait a bit for the hot water but a recirc is a cheap option if you want to go that route."Certified" is probably not that big of deal, you won't get a warranty from Uponor and if you pass a pressure test, how can the BI hassle you as a homeowner doing your own work that meets code?
Thanks for pointing that out to him.
I've been so busy with my pyro suppliers I haven't had much time to get on BT.
That wrong barb can spell disaster when you least expect it.
Pyro, now you've got my attention...I've ALWAYS wanted a pyro license...have a couple of friends who have licenses and wow I wanna get paid to shoot off fireworks and blow stuff up!!
But seriously the manabloc manifolds come in a compression style fitting shouldnt that be tubing independant?
Daniel Neumansky
Restoring our second Victorian home this time in Alamdea CA. Check out the blog http://www.chezneumansky.blogspot.com/
Oakland CA
Crazy Homeowner-Victorian Restorer
Yes the tubing is fine, but don't try the Uponor memory ring on a barb that isn't Uponor brand.
I don't have my license yet, so I make sure that anything I build or set off is under the 500gram limit----- wink wink nod nod.
People around our cabin are donating for me to put on a big show, so i suppose this will be the last year without a license------ I guess I was going to have to follow the rules some day ;-)
I've seen wirsbo/upnor used with compression, crimp, no rings and hose clamps.
The problem may be when your inspector comes by, wirsbo isn't certiified for anything but their own system. He could shut you down.
Yea that could be a good point...and I'm pretty sure I'll be the first PEX manifold home-run system any of these guys have ever seen.
I KNOW the inspector that I got last week had never seen a radiant heating system before...him inspecting my work was comical...but he passed it so I can't complain too much.
Daniel Neumansky
Restoring our second Victorian home this time in Alamdea CA. Check out the blog http://www.chezneumansky.blogspot.com/
Oakland CA
Crazy Homeowner-Victorian Restorer
Ok then.
Get certified and then invite the inspector over so he can see pex in actual use. Let him use you to see how it is supposed to be done. Let him make some joints. Fill a piece with water, cap it and throw it in the freezer ahead of time for him to see. Really wow him by kinking the pipe and then heating it to remove the kink.
Have the design manual available for him. And show him some of the "drawbacks", like it expands when heated so you have to allow for expansion. Be his "expert".
And have coffee available.
Betcha you pass with no problems.
Rich, Bill,
I know that the manabolc is a Vanguard product but it comes in a compression fitting style that should be PEX manf independant no? At least that was my reasoning...
Daniel Neumansky
Restoring our second Victorian home this time in Alamdea CA. Check out the blog http://www.chezneumansky.blogspot.com/
Oakland CA
Crazy Homeowner-Victorian Restorer
I am about to plumb in my house as well with PEX. I picked up a whole house kit from Mountain View Supply (mvsupply.biz). It's a 1/2" Viega/Vanagaurd Manabloc and they supplied 1/2" -> 3/8" reducer fittings for the manifold. Pretty much everything but the kitchen sink included in the package.
I'm going with crimp connectors as I was able to pick up a Zurn 3/8" crimper for $18? at Lowes, and a PocketCrimper (http://www.pexcrimper.com/) for 1/2"/3/4" for $30, which will do the entire house. Not fast, but I'm only going to do this once, so what heck does it matter if it takes me 45 seconds to make a crimp?
Z