Problems with PEX plumbing?

Link to my Podcast on the subject: Problems with PEX Plumbing

Even though lead pipes were used and researcher found elevated levels of lead in Roman water levels, some research has revealed it wasn’t the main cause of the demise of the Roman Empire. However, it is dangerously toxic.

The CDC warns us High levels of lead in tap water can cause health effects if the lead in the water enters the blood and causes high blood lead level. It can cause damage to the brain and kidneys, and can interfere with the production of red blood cells that carry oxygen to all parts of the body. EPA has set the maximum contaminant level goal for lead in drinking water at zero because lead can be harmful to human health even at low exposure levels. Lead is a toxic metal that is persistent in the environment and can accumulate in the body over time. (Lead in Drinking Water) Also, more than 40% of the Atlanta schools recently had elevated lead levels in their drinking water.

No – PEX pipes don’t create or introduce lead. But can we learn from the Romans that we need to be careful of the plumbing materials we use for our drinking water?

Furthermore, we’re told by health professionals and nutritional experts we shouldn’t drink water from plastic bottles, practically everyone does. Glass containers are supposed to be safer and healthier.

So why do we choose to drink water out of plastic pipes?

Simple – new construction and cost.

PEX pipe used in many new homes today is a cross-linked polyethylene tubing. It’s easier, cheaper, and requires less overall plumber time,…and that’s good for home builders to reduce costs whenever possibie. Copper is expensive, CPVC is also time consuming for many straight runs and joints. So the recent quick alternative was to use a flexible tubing and install joints at end of connections.

However, what has been revealed through its use is defective PEX fittings. Some were first introduced in the 1990s, but the problems are really just now coming to light. 

There are two problems that come from high zinc content in brass fittings.

(1) when water flows through the high zinc brass fittings, the zinc in the fittings leaches out of the fittings (DeZincificatin) which causes failure of fittings.

(2) the leaching of zinc also causes a white residue to build up inside the pipes, constricting water flow. 

If you have a plumber out and you can find out exactly that type of PEX pipes you have in your home or business, you will be ahead of the game. The following are commonly found problems associated with specific types of PEX pipes:

  • PEX-A (Uponor/Wirsbo and Rehau): dezincification of fittings and chemical leaching/odor (AquaPEX only)
  • PEX-B (Zurn & Viega): dezincification of fittings
  • PEX-C (Nibco/CPI/DuraPEX): cracked, leaking pipes
  • PEX-AL-PEX (Kitec/IPEX): dezincification of fittings

Issues with PEX plumbing and fittings

PEX may leach BPA and other toxic chemicals. There are 3 types of PEX (A, B, and C), but type B is the only one that doesn’t appear to have the leaching problem. The research is still incomplete on this matter, but if you want to use PEX, you may want to choose type B.

PEX is extremely sensitive to UV light. UV light doesn’t just mean sunlight, even the bulbs in your home are UV lights. Most manufacturers recommend a limited amount of sunlight exposure, which is important to note during the installation process, and others recommend total darkness.

PEX can be damaged by chemicals and pests. Some pest control companies argue against installing PEX because it’s so susceptible to pest damage. Since PEX is plastic, it’s more sensitive than copper and other metal pipes. Mice can chew right through the pipe, causing major problems. The thing to keep in mind though, is this is more of a rodent problem than a PEX problem.

PEX can’t be installed in high heat areas. You can’t install PEX in high heat areas like near recessed lighting. This also means you can’t connect PEX directly to a hot water heater, but you can use a connecting material to do this.

PEX is semi-permeable, which means liquid can enter the pipe. When it comes to safety, PEX isn’t antibacterial. This is one reason people don’t choose PEX in the PEX vs. copper decision. The plastic material also allows water to enter the tube, which could cause contamination.

  • Improper installation – Failure to install bend supports to prevent kinks when making tight turns which cause improper bends and cracks; or missing nail protection plates to prevent accidental PEX pipe punctures.
  • Defective manufacturing – Does anyone remember the class action lawsuits from polybutelene plumbing? If you have Dura Pex, you may still be able to get in on the class action suit that has been filed against NIBCO CPI Dura Pex. Check out information on class action lawsuit for homes and businesses using Dura PEX pipes.
  • DeZincification. This is when certain water chemistry causes selective leaching of zinc from brass alloy, resulting in weakening of the fittings and leakages.
  • Improperly calibrated tool. When using crimp or clamp/cinch to install a PEX system, the tool should be calibrated beforehand and periodically checked by a professional to ensure the job is done right.
  • Failing to pressure test. Failure to abide by pressure testing requirements may not only result in leakages, but also require removing of entire walls/floors, fixtures and other costly repairs.
  • Burst/frozen pipes. While more burst-resistant than copper, in extremely low temperatures, when water completely freezes in the pipes, PEX pipes have a little give, but are still susceptible to bursting.
  • Over-chlorination of water. Water containing high levels of chlorine is highly aggressive, especially when the water is hot. If water is over-chlorinated or if the piping system is sanitized by treatment with high concentrations of chlorine, the service life of the pipe is greatly reduced.

Suggestion: Get your water tested. You water pH should be at or above 6.5 and your water chlorine concentration should be at or below 4.0 ppm (parts per million).


Live with it and fix the leaks and fittings when they occur.

Install a whole house water filtration system (installed at the point of water supply entry to your home) that removes chlorine, chlorine by-products, and helps with pH.

You can hire a plumber to switch you over to DZR (DeZincification Resistant) brass or poly PEX fittings, both of which are not susceptible to corrosion.



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