Plumbing question: push-to-connect fittings

[wh500special 2,277]

I need to install a new water heater soon.  My current electric tank model is about ten years old and I am seeing enough corrosion on the hot water pipe coming out of the top that I think it's time to be preemptive before it blows.  For a variety of reasons, I want to switch to a gas fired tankless model not the least of which is a teenager who takes leisurely shower.

 

I was looking for a spot to mount one of these contraptions and a nearby wall concrete wall is pretty convenient and happens to be right under the gas line and provides decent accessibility for the incoming air and exhaust flues.  So, as these things go, probably a fairly simple install.

 

I am a terrible plumber and really fret the process of sweating copper pipes.  I've done it before and never had a leak, but it isn't something that makes me feel good.  That and the fact that it will take me a bunch of elbows and fittings to get from the house plumbing to the bottom of the tankless unit is making me consider PEX and the push-fit fittings (like Sharkbite) to make the final connections.

 

I have never used PEX.  I have plumbed hundreds of airline connections with push fittings at work and have never had a single leak.  it seems like a proven technology.

 

Are there any decent reasons to avoid this approach or transitioning the 3/4" copper to PEX and making direct connection to the bottom of the new heater?  Can you connect PEX directly to the HWH or is another transition needed?

 

I know many plumbers probably prefer copper since it's what they do, but i'm curious about this stuff.   it looks like I can do the whole job with a handful of fittings and a few lengths of tube compared to a bunch of copper elbows and a whole lot of cussing.  plus the stomach wrenching stress I get from the copper process.

 

I suppose I can buy a crimper and use conventional PEX fittings, but I don't really see why a push-fit fitting can't work long term.  Water heaters only last about 10-15 years anyway and i don't plan to be in this house forever, so I'd imagine that the fittings ought to be good for that long.

 

The other question relates to how to you typically support a PEX tube on exposed work?  I can't let it dangle and flap, but it looks a lot like most PEX installs are buried in walls and trapped by studs.

 

Thanks,

Steve

[Racinbob 11,949]

I'm not a plumber but I've done quite a bit from copper to PVC and just recently did a complete replumb on a house. I was thinking copper was the way to go but after hours of research and talking to union plumbers it became a no brainer. PEX is the way to go. It has benefits over and it actually superior to copper. I would suggest to avoid fittings like 90° fitting whenever possible simply to avoid the restriction and extra connections. Depending on your situation there are many options to support the PEX and it can be made to look professional. Included in my research, of course, was fittings. I would suggest avoiding the push to fit. I used the crimps. Even avoiding unnecessary fittings the fact that I did three baths, kitchen, launder, etc. and all zoned off required a lot of crimps. Number of issues? Zero. Non metallic piping like PVC, CPVC and PEX aren't supposed to be connected directly to a regular water heater so I would imagine it's the same for a tankless. 

[oliver2-44 10,738]

I just piped a house addition for my son and used the Pex push to connect fitting.   It was fairly simple with sink and shower back to back, so not a lot of piping.  I did some research and theres some good info on youtube and as always some bad info. (some of the bad info is the rubber O-rings in the push to connect fitting will not stand up to the clorine in city water.  A little more research and as I suspected the O-rings are Viton, which is fine for chloring water use.  About 10 years ago I used some Pex push to connect fitting at my house when i walked into the garage barefoor one morning and felt warm concrete under my feet.  Yep, copper line in slab from hot water heater to first connect in house which was the wash machine had a hole a pinhole in it.  The push to connect fitting are not cheap, so if you require a lot of fitting ithey may not be the way to go.  Just my opinion, but I would not use copper.  If you go with the push to connect fitting buy the little gauge that you mark the pipe for the correct insertion depth into the fitting.  The gauge also has a little deburing feature for the cut end of the tubing, but it a little cheezy.

[squonk 43,857]

I ‘be seen a lot of crappy copper. Pex and brass fittings should hold up well

[ohiofarmer 3,372]

I never had a problem with 50/50 lead solder, but the lead free stuff is not very forgiving. Silver solder works better.   if you are not comfortable plumbing Pex as a direct connection to a water heater, you could make up a sub assembly from copper and then use a push to fit connector as a way to assemble your sub assembly to the house plumbing. The huge advantage of using at least one push connect fitting is that all your sweat soldering is done with clean dry pipes. It can really be a bugger to make that final sweat joint on copper if a bit of moisture is trying to escape as the pipe heats up.

 

 What you could do is simply make up a couple of  12 inch copper stacks with a dielectric fitting or purchase all in one threads to pushlock hoses from a store like Lowes

 

  If yomake your own connection to the heater, Make sure that you use a dielectric union to the water heater if connecting metal piping, as connecting copper directly to the water heater will eat away at the iron fittings of the water heater. I just replaced an expensive pressure tank for a well system that was not connected with the proper brass manifold , but a copper pipe that rotted the iron tank fitting at the tank away

[Racinbob 11,949]

I simply used a brass 3/4" PEX to 3/4" npt drop ear fitting mounted behind the water heater and connected it with standard water heater connectors. I used stainless. 

[WHX?? 51,806]

I would go with regular pex fittings but only cause all I would have to do is back my work truck up to the door and have everything I would need! Shark bites can get a bit pricey for me but they would work fine. They offer a whole host of clamps, hangars and what not for support.  Make sure you get a valve kit for the tankless. Think the advice of a plunger who puts bacon on his table by doing this is needed here @JCM….

[wh500special 2,277]

Thanks guys.  I appreciate the input.

 

I like the idea of PEX.  There isn't much in this world that holds up like polyethylene.  And man is it cheap.  Even to buy a crimper and whatnot isn't expensive.

 

These push-fit fittings just seem almost too good to be true.  Sure, they are $8 apiece, but some of the plumbing quotes from a real professional were up to $450 just to make the water connections after I have already hung the unit, ran the power, and connected the exhaust and drain.  I could use 56 fittings and still be cheaper.

 

I want to get this done soon.  I plan to call the plumbing place and buy the heater and support gear this week.  Once I have it sitting here it becomes something I can chip away at in the evenings after work.

 

I also need to install a water softener at some point.  Like most places, our water is very hard.  I imagine my electric tank water heater will weigh a million pounds due to the accumulated schmutz.  i was amazed at how much rock had built up in our dishwasher which conked out in October.  Didn't bother to replace it yet since I figured I'd wait until I had a softener.  But we haven't really been missing it.

 

I had the foresight to have the plumber put a loop with valves in when the house was built, so there is no breaking into the main supply required.  But wouldn't you know it, he left me with two socket type ball valves sticking there waiting to be soldered to.  No cheater's way around that problem...

 

Steve

[Pullstart 66,900]

Keep in mind a tankless water heater takes a proprietary vent system.  Whatever brand you go with, get their venting too.  Also, it would be a good idea to be sure you have enough gas supply to get the throughput of all appliances firing at once in a worse case scenario.  Often times a house doesn’t have enough volume to support another 150k+ btu appliance that was originally built for a 40k btu water heater or in your instance electric.

 

Best wishes with your decision.  I try to be unbiased when talking about tankless, but I have never been convinced that the pros outweigh the cost + cons.

[ohiofarmer 3,372]

14 hours ago, wh500special said:

Thanks guys.  I appreciate the input.

 

I like the idea of PEX.  There isn't much in this world that holds up like polyethylene.  And man is it cheap.  Even to buy a crimper and whatnot isn't expensive.

 

These push-fit fittings just seem almost too good to be true.  Sure, they are $8 apiece, but some of the plumbing quotes from a real professional were up to $450 just to make the water connections after I have already hung the unit, ran the power, and connected the exhaust and drain.  I could use 56 fittings and still be cheaper.

 

I want to get this done soon.  I plan to call the plumbing place and buy the heater and support gear this week.  Once I have it sitting here it becomes something I can chip away at in the evenings after work.

 

I also need to install a water softener at some point.  Like most places, our water is very hard.  I imagine my electric tank water heater will weigh a million pounds due to the accumulated schmutz.  i was amazed at how much rock had built up in our dishwasher which conked out in October.  Didn't bother to replace it yet since I figured I'd wait until I had a softener.  But we haven't really been missing it.

 

I had the foresight to have the plumber put a loop with valves in when the house was built, so there is no breaking into the main supply required.  But wouldn't you know it, he left me with two socket type ball valves sticking there waiting to be soldered to.  No cheater's way around that problem...

 

Steve

 

[ohiofarmer 3,372]

 Well, here is more advice whether you want it or not. As far as water softeners go, get one with a Fleckenstein valve. Commonly called a Fleck valve.  I have a Fleck 5600 and it started leaking after many years of service. I got a rebuild kit for around forty dollars and now the softener runs as new. The rebuild is very simple and only takes a half an hour watching a video . Doing a second valve once you know how is maybe fifteen minutes.

[wh500special 2,277]

Thanks again. 
 

I have read that same comment on the water softener valves elsewhere.  
 

My last two homes had softeners, but this one doesn’t (yet).  I never liked the feel of the soft water, but seeing how everything here is limed up reinforces that they are often needed.  
 

Good point on the gas line

 capacity.  Although I didn’t run a pressure test, I’m confident I have enough gas coming in.   The builder set these homes up with a 1-1/4” (might be inch and a half, don’t remember without looking) pipe from the meter down the center of the house to accommodate the optional extra fireplaces some buyers installed in their master bedrooms and basements.   I don’t have either of those add ons, so I have extra capacity (I live by the mantra of have the cheapest home in a nice neighborhood...it artificially raises the value of your house). 
 

The furnace is fed off the same line, but it is plumbed from that master pipe to the unit on the drop with 3/4” black pipe.  The HWH says it is serviceable with 1/2” on a short drop, 3/4” otherwise.  1-1/4” pipe is almost three times as big as 3/4”, so it ought to be fine. 
 

the plumbing supply place is currently out of the tankless unit I was looking at (Navien 200 or something like that).   Can get one in a day or two.  That bought me a little time.  I was also looking at a heat pump type tank model and they are intriguing.  
 

with tax incentives and rebates, a heat pump tank unit is Barely more  costly than an electric identical to what I have now. 
 

that changes things.  
 

I thought the idea using the room heat to heat the water seemed silly, but the advantage is in the summer it would be a nice dehumidifier in the basement.  In the winter, the furnace sitting next

to it really heats up that room anyway with waste heat so there is extra heat that isn’t doing much for me in that otherwise unused storage room. 
 

They still have regular heating elements in them, so even if the heat pump function is sluggish I’d be no worse off than I am now.  
 

my daughter would just have to live with a normal shower.  And we’d still have the occasional power outage loss of hot water.  
 

oh, the humanity. 
 

to the original point though, I think I’ll use PEX and the push fits.  
 

steve
 

 

[953 nut 60,141]

21 hours ago, pullstart said:

tankless water heater takes a proprietary vent system.  Whatever brand you go with, get their venting too

When we built our house I installed a Navien Tank-less Water Heater because the heat exchanger is stainless steel and you can run PVC vents. The unit cost more, but the installed price was less. With hard water you MUST do a regular descaling to prevent buildup. Not a hard job, you can do it yourself.

https://www.navieninc.com/

I did all the plumbing and used PEX, love it. The push on fittings work fine. I have had to transition from copper to PEX a few places at our church during renovations and had no problems.

[EricF 589]

I hate doing plumbing, but when I have to do it, I want it done right so I don't have to go back and fix it later. Sweating copper pipe and fittings is actually pretty easy if you prep the work right and then let the heat from the torch do its work.

 

Prep is really the key -- be sure to scuff/ream/deburr the surfaces you're putting together so the solder has something to grip onto. Plumbers will tell you that deburring is really important, and not deburring is one of the biggest sources of failed joints.

 

Flux the surfaces thoroughly and use a MAPP gas torch, especially with the newer solder, and make sure to get the whole joint nice and heated up so you see the flux begin to run out and do its job of getting the solder pulled into the joint, and then make sure to wipe up/clean up the joint when you're done. Every plumber I've ever talked to says the cleanup is as important as getting a good solder joint for a failure-proof job. (Think of it this way -- don't ever give water any chance to follow capillary action and work its way into a weak spot.)

 

Get a heat shield if you're working close wood or other combustibles -- better safe than sorry, and you'll be more confident applying the heat if you're not worried about setting something on fire. 

 

And for pipes where moisture may drip into the work area, the plumbers' trick is to stuff some cheap white bread back into the pipe and then dry the work area. The bread keeps the moisture away like a sponge. When you turn the water back on, the pressure and water will dissolve it away instantly. 

 

I learned not to fear sweating copper once I learned how to do it right. I've done joint repairs and brass valves, too, and never had a leak, knock on wood.   My joints might not be as pretty as ones done by a plumber who does it for a living, but I've saved plenty of money and delays getting it done myself.