Pex: plastic taste in water

NetWareHead

THAT guy
Aug 10, 2002
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Replumbed my entire house and we chose pex tubing on plumber's recommendation. You guys may remember a thread I made earlier this year where I discovered rotten plumbing when I took out some walls and decided to do it all over. The water enters the house from the street via a copper line and from here various runs of pex take off to go to various bathrooms, kitchens etc...

The water has a bad plastic taste to it. I just don't like it. We have another house on the same municipal water system so its not the city water. The tubing has been in the walls for a few months now, faucets were installed last month and began use. I hope this is something that just needs to leach out of the tubing and the taste will go away.

I haven't been living there full time so the tubing doesn't get "normal" usage, perhaps this is a factor... I hope that if the pipes were used normally, the plastic taste will eventually wash out. Only time will tell.

Don't get me wrong about pex now. We plumbed the supply side of a 2 story house: 2 full bathrooms, 2 kitchens, 2 laundries and outdoor sillcocks in less then 2 days. That's impressive from a labor standpoint when compared to copper. No soldering, no expensive copper, just durable brass fittings where needed. One tool needed: a tubing expander needed to make connections to other fittings, pipes etc... The tubing can make direction changes easily. Fewer joints overall in the tubing run. Freeze resistant, no corrosion or pinhole leaks. Even if the tubing gets kinked, hit it with a torch and the plastic will reset itself back to normal shape!

Anyway, this is for a rental and if my tenants complain, I can only point to the fact that this tubing is rated for residential potable water supply and to get a Brita filter if it bothers them that much. (Btw, I still drank this pex water, I'm not afraid of the quality just the taste). For my own house, I'll still use pex tubing but for stuff like laundries, toilets, sillcocks and bathroom fixtures. The kitchen sink where we will get the majority of our drinking water from will be a hard copper line.

Using Uponor Aquapex which is Pex-A from what I understand. Anyone know if the taste disappears over time?
 

DrPizza

Administrator Elite Member Goat Whisperer
Mar 5, 2001
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I think there are quite a few questions surrounding a taste imparted to water by Pex. My personal feelings is that it has something to do with the specific manufacturers. We used to like the taste of our well water, but in the past year or so, it started getting an off smell to it; not quite like sulfur, but something similarly not as pleasant. Prior to that, I thought our water was incredible. As such, the only water we drink at home is bottled water. We go through a case or two or three a week. For only a short while, I considered bottle water to all be essentially the same. But, I've noticed that for certain brands of bottled water, there's a bit of a plastic taste, and for other brands, that taste is completely absent. In no case was I unable to drink the bottled water that I purchased, but it did guide my future brand selection; and especially guided my wife's brand selections. But, afaik, all those water bottles are made of the same material. Thus, I think that something's happening in the manufacturing process that results in some component or byproduct of the manufacturing process to exist on the surface that can impart such a flavor. This is only my hypothesis, but I think that hypothesis is reasonable and extends to PEX manufacturing.

When we purchased our house, (foreclosure property), the bank had turned off everything 2 years prior - no heat, etc. And, they didn't drain the lines, thus every last bit of plumbing, as well as all the heating system (hot water baseboard) was destroyed by burst pipes from freezing. Took us just a couple of hours to replumb the entire house with new PEX lines - we used Wirsbo brand, I believe. And, zero taste imparted to the water - as I said, the water taste was far better than the city water we were accustomed to.

If my hypothesis is correct though, it also means that eventually, the taste will go away. And flushing the lines is actually mandated in California for new homes. I think their process is flush, then let sit for a week, then flush thoroughly again.
 

nathanddrews

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My wife can't taste it, but she thinks I'm a "supertaster" since I can often smell and taste things in food or in the house that she can't. Anyway, we recently ripped out all of our copper pipes to install pex and replumb the entire house (new bathrooms, moving the kitchen, etc.). It's been about six months and the taste is still present. We have used four different brands of pex tubing - from Home Depot, Menards, Amazon, and SupplyHouse.

We went with pex because of its supposed benefits. The pex and new manifold made everything easier for sure, but I can't drink the water. The taste is so overpowering that even the ice cubes end up adding plastic taste to my drinks. It's that bad.

I'm not sure what to do at this point. The ceilings in the basement are all still open and we still have the old pipes in a pile (I haven't scrapped them yet), so I'm tempted to rip out all the pex and put copper back in where I can. Thankfully, using SharkBite fittings makes using copper a lot easier.

If someone were to ask me if it was worth it, I would say no:

1. Plastic taste
2. Lower water pressure
3. Cost of fittings, tools, and manifold end up being more than copper
4. Heat loss, it takes much longer to get hot water than it did before, even with shorter runs
 

NetWareHead

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Aug 10, 2002
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Any experience with the taste improving when passing the water through a Brita or similar filter?
 

herm0016

Diamond Member
Feb 26, 2005
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My wife can't taste it, but she thinks I'm a "supertaster" since I can often smell and taste things in food or in the house that she can't. Anyway, we recently ripped out all of our copper pipes to install pex and replumb the entire house (new bathrooms, moving the kitchen, etc.). It's been about six months and the taste is still present. We have used four different brands of pex tubing - from Home Depot, Menards, Amazon, and SupplyHouse.

We went with pex because of its supposed benefits. The pex and new manifold made everything easier for sure, but I can't drink the water. The taste is so overpowering that even the ice cubes end up adding plastic taste to my drinks. It's that bad.

I'm not sure what to do at this point. The ceilings in the basement are all still open and we still have the old pipes in a pile (I haven't scrapped them yet), so I'm tempted to rip out all the pex and put copper back in where I can. Thankfully, using SharkBite fittings makes using copper a lot easier.

If someone were to ask me if it was worth it, I would say no:

1. Plastic taste
2. Lower water pressure
3. Cost of fittings, tools, and manifold end up being more than copper
4. Heat loss, it takes much longer to get hot water than it did before, even with shorter runs

what kind of fittings did you use? and did you use the correct size for the runs? low pressure is a system design issue, not a issue with the material.
copper has a much higher conductivity and will cool the water much faster than pex will. the extra time has nothing to do with heat loss. the extra time is due to the poor system design and related to the lower flow rate you are experiencing as a low pressure at the faucet.

as far as the taste goes, i have been in many places with pex lines and not experienced a taste difference. i imagine it is due to a difference in quality of pipes or fittings. using many different brands of pipe and fittings could create issues as well.
 

Tommy2000GT

Golden Member
Jun 19, 2000
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This is another reason why I'm still not sold on PEX.

For my whole house remodel which I had to replace the galvanized pipes, I used copper "L" pipe for inside wall and "K" pipe for underground. It cost me a fortune but I wanted a piece of mind.
 

DrPizza

Administrator Elite Member Goat Whisperer
Mar 5, 2001
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My wife can't taste it, but she thinks I'm a "supertaster" since I can often smell and taste things in food or in the house that she can't. Anyway, we recently ripped out all of our copper pipes to install pex and replumb the entire house (new bathrooms, moving the kitchen, etc.). It's been about six months and the taste is still present. We have used four different brands of pex tubing - from Home Depot, Menards, Amazon, and SupplyHouse.

1. Plastic taste
2. Lower water pressure
3. Cost of fittings, tools, and manifold end up being more than copper
4. Heat loss, it takes much longer to get hot water than it did before, even with shorter runs
A) Why did you use 4 different brands of Pex? Now, you won't know which brand is the culprit for giving the water an off-taste.
B) Lower water pressure has nothing to do with using PEX. If you have less water flow, it's a result of improperly sized lines or manifold.
C) Egads, what did you do? Use sharkbite fittings for everything?? A run of Pex requires far fewer fittings than a run of copper, due to its flexibility. While an individual fitting is a little more expensive, you pretty much break even due to needing fewer fittings. (If you did a whole house, I hope you didn't buy them individually... though with purchasing a little bit of Pex at a time, since you used 4 suppliers, it implies you were buying fittings a couple at a time. ) That the pex line is so much cheaper per foot is the icing on the cake.
D) Let's put it this way - if you put hot coffee in a copper mug and try to pick it up immediately, you're going to burn your hand because copper conducts heat a lot better. If you fill up a plastic mug, it takes a longer for the heat to get through. And, per gram, copper absorbs twice as roughly twice as much heat as Pex. (Specific heat .385 vs. .190 J/gK
 

nathanddrews

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Aug 9, 2016
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We could not have used fewer fittings than we did:

3/4 from main to water heater (one sweep)
3/4 hot and cold from water heater to manifold (one sweep each)
1/2 to all outlets (one sweep each)

It was understood that the internal diameter of pex is slightly smaller than copper, but that by running continuous sweeps without elbows or connectors would make up for that (lower friction coefficient, etc.). We have no leaks, no kinks. To be clear, it's not a massive pressure reduction by any means, but it is noticeable.

Like you said, Pex is supposed to be less conductive than copper. I'm going to buy some more pipe insulation and wrap every last foot and see if that helps regulate temperatures better.

Since the taste only seems to bother me, I'll probably get a water filter to keep in the fridge.
 

Mandres

Senior member
Jun 8, 2011
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We have used four different brands of pex tubing - from Home Depot, Menards, Amazon, and SupplyHouse.

Are you saying re-plumbed the whole house 4 times using different brands of tubing with the same results? I find that a little hard to believe.

I'd be curious if anyone has done real, double-blind studies to see if people can really detect a taste difference between PEX, copper and PVC. Maybe this is true, and certain brands/formulas of PEX can impart a taste, but this sounds more like FUD being spread to me..
 

nathanddrews

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Are you saying re-plumbed the whole house 4 times using different brands of tubing with the same results? I find that a little hard to believe.
No, we did the conversion in two large stages, then we didn't order enough length, then Menards ran out of the size we needed, so there were a number of contributing factors that led to the multiple suppliers of pex.
I'd be curious if anyone has done real, double-blind studies to see if people can really detect a taste difference between PEX, copper and PVC. Maybe this is true, and certain brands/formulas of PEX can impart a taste, but this sounds more like FUD being spread to me..
That's me, a shill for Big Cu. You can believe it or not, but a season later, the water from the faucet still tastes like plastic. I ended up buying a large water filter to keep in the fridge so I don't have to worry about it. No discernable taste and it's always ice cold.