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View Full Version : How to plumb hot water to a shared washer


artm
Sep 19, 2013, 02:27 PM
Hello all, first time here... I'm installing a washer in the basement of a three family. Rather than install a common water heater I'm considering doing a shared setup for the hot water for the washer.

So, here's what I thought, remembering that each water heater already has a shutoff valve for the hot line specifivally to the washer and lines are 1/2-in:

1. at each water heater,
Sweat-pex fitting 1/2-in >
1/2-in pex pipe >
Pex-sweat 1/2-in >
Paddle shutoff valve >
3-to-1 1/2-in copper "manifold" >
1/2-to-3/4 thread >
Washer hose

So, each unit will use their own shutoff valve at the washer end to select their line. I know, I know - I'm on the honor system here but it is what it is. I will have three pex lines from the water heaters to the washer and then down to one.

2. at each water heater,
Swing check valve 1/2-in>

Close to the water heaters:
3-to-1 1/2-in copper "manifold" >
Sweat-pex fitting 1/2-in >
1/2-in pex pipe >
Pex-sweat 1/2-in >
Paddle shutoff valve >
1/2-to-3/4 thread >
Washer hose

So, here I have all three lines constantly "on" and shared when the washer demands hot water. I have the manifold at the water heater end and only one line going to the washer. The swing check valves are obviously there to prevent backflow. If a unit doesn't want to participate in the laundry, then I simply shut off the valve at the water heater and their line isn't in use.

I'm using pex for the long runs for its ease and, possibly, cheaper cost.

Any help is appreciated.

massplumber2008
Sep 19, 2013, 03:38 PM
Hi Artm

I see you've put a lot of thought into this, BUT at the price of PEX tubing, I'm pretty sure your best bet is to just run 3 separate lines over to each washer... will be cheaper for you and less hassle for everyone in the long run... ;)

All those fittings (manifold, check valves, misc. fittings) and the fact that you are already running one hot water line over to the washer strongly suggests to me that it will be much better to just run 2 more PEX lines and not have to worry about the "honor system" in any way!

That's my thoughts!

Mark

artm
Sep 19, 2013, 04:20 PM
Mark,

Thanks for the reply. To clarify I've attached a pic of the two setups. So we have:

Setup 1: the honor system involves three lines to the washer and each unit operating their own valve.

Setup 2: all sources are always on

Some points:

- the "manifolds" are just copper T's and pipe, nothing fancy.

- the check valves I assumed were necessary to prevent water going the wrong way (back to the other water heater). They make the flow go to the washer only since in that setup all 3 lines are "alive". In setup #2 I don't need them as long as only one shutoff is active at the washer end - where each unit selects their line. I control the shutoffs at the water heater end.

So, are you saying:

- that setup 1 is cheaper?

- I don't need check valves in setup 2?

You said: "just run 3 separate lines over to each washer". To be clear, there is only one washer and three water heaters. So..

Thanks again.
Art
Boston, MA

massplumber2008
Sep 19, 2013, 04:43 PM
Hi Art

Oops! Sorry, missed the SINGLE washing machine concept... UGH!

Setup#2 looks fine to me. I can't speak to whether this is "legal" in terms of acceptable plumbing code, but I can see how you've made it work. Interesting here is that in 35 years I've never seen it done, so it leads me to thinking somebody that likes to make rules would find a problem... ;)

How about instead of piping as presented you simply charge these people the same rate (or cheaper) per wash as a local wash/dry center... on the honor system and just go off the main water heater? It seems to me a lot easier and cheaper for you, or is this a 3 family and no owner present?

Anyway, your setup looks OK to me.

Mark

artm
Sep 19, 2013, 05:34 PM
Mark,

It is a non-owner occupied three family without a common water heater. I have no intention of hiding anything here as it will be noted in my leases that the hot water will be fed off the tenants' water heaters. If someone doesn't like the setup they are free to opt out and not use the facilities. Of course, there is the possibility that someone will opt out but still use the washer.

Also, it will be a coin-op setup but I just don't see the need to go to the added expense of an electric common water heater if the tenants opt in. Frankly, I know that they won't have a problem with it as the convenience far outweighs the lack of on site laundry.

As far as plumbing code, well, that's for a plumber to say whether it's legit.

massplumber2008
Sep 19, 2013, 05:57 PM
As far as plumbing code, well, that's for a plumber to say whether it's legit

Well, a plumber just told you as nice as he could... probably not "legit" as you are crossing 3 hot water systems, 3 separate gas systems (each has its own gas meter) and you are NOT pulling a permit!

To see why plumbers/codes enforcement/engineers, etc. take this so seriously, visit:

www.waterheaterblast.com

As much as this isn't anything to do with what you are proposing, you may see why codes enforcement might frown on messing with water heaters in almost any way... ;)

With all that being said, and with codes and inspectors being different from city to town and from state to state it couldn't hurt to call a SEMI-local plumbing inspector and see what he thinks of all this!

Mark

hkstroud
Sep 19, 2013, 06:26 PM
I think you are setting yourself for a lot of bickering among tenants. Put in another water heater, amortize it over 5 years. Write it and the cost of gas off on your taxes.