Pinhole leak in PEX pipe coming from tankless water heater

[Relax]

My son asked me "Is that noise coming from the basement normal?" As I near the top of the stairs, I hear the dreaded sound of splashing water and run downstairs to find water spraying out from around the tankless water heater. Turned off the input valve to the heater, and the splashing slows. After calling Reliance to come look, I go back down and dry everything off to take a closer look. I thought one of the PEX fittings came loose, but when I reopened the input valve I could see water spraying from a pinhole in one of the PEX tubes coming out of the heater. Reliance says that they need the technician to confirm whether that's covered by the water heater rental agreement, but they believe only the tank itself is, not any of the plumbing or valves.

So my first question is, what could cause a pinhole leak to develop? It's not on the side of the tube touching the wall that it's mounted to, it's shooting out the side, and about halfway between the ends of the tube. This really affects my impression of the reliability/durability of PEX compared to copper, and puts a damper on my plans to eventually replace all of my copper with PEX.

The next question is - if it's not covered by Reliance and I need to fix it myself, can I just cut the section out with a hose cutter and rejoin them with a PEX union, or do I need to replace the entire length of PEX because it's compromised, and how do I know if any other pipes will do the same soon (or later)?

 

[ToSlow]

Probably failed from the inside out. See this a lot on hyd hoses when heat is involved. Everything has an abrasive factor water moving through the pipe probably found a weak point and started wearing on it

 

[Charles13]

I don’t understand the move away from copper, pex is easy but copper is “copper” and thus is very durable

 

[crankcall]

I would not remove copper in favour of PEX , but any new install I do would be pex . I think if i were in your situation I would replace that entire section of pipe if possible, or as much as you could access without ripping up the house . Could be a one time manufacturer defect or worn as @ToSlow mentioned, but I’d want a decent section replaced.


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[Sky_high]

I don’t understand the move away from copper, pex is easy but copper is “copper” and thus is very durable

When we bought our house in 2015 (which was built in 1958, and has copper piping), TD Insurance would not insure our house unless we converted it to PEX piping. We ended up having to find another insurance company that would insure us with copper.

 

[Charles13]

When we bought our house in 2015 (which was built in 1958, and has copper piping), TD Insurance would not insure our house unless we converted it to PEX piping. We ended up having to find another insurance company that would insure us with copper.

Did they say why? Where you leaving it uninhabited/ heated or something? I had TD insurance for years and they never mentioned anything of the sort.

 

[Mad Mike]

If you plumbing is pre 2008, look for markings Kitec,” “Ambio Comfort,” "XPA,” “Ipex Aqua,”T. If so, this pipe would need to be replaced asap.

 

[oioioi]

From my experience Reliance only covers the tank and nothing else.

I would cut out the defective part and replace it with a new piece of PEX.

 

[Soulcatcher668]

The move to PEX was entirely money driven.
It is much faster to run and requires less skill and planning. This save tons on labour and as we all know people are expensive.

There have been many lawsuits involving PEX from different companies.

I hate the stuff. I have one area in my house that has it, if you take water from that tap, you can taste the plastic.

 

[Ash]

Exposed PEX is super easy to work with. A crimp tool and rings are less than $100 if you want to get up and running again quickly. I'd be very interested to see the condition of the inside of that tube near the pinhole. Manufacturing defect or overall degradation?

 

[Relax]

Awesome. Nice to wake up to some replies since Reliance isn't showing up until "sometime between 1-5" today.

@Mad Mike - Here's a couple of adjoining pipes that I could get a clear pic of the markings, don't see any of the ones you mentioned. In any case, if I had to replace everything, I think it's only about 25 ft total PEX plus the clamps until it joins to copper. Can I reuse the elbows, or are they "one-time use" Now to figure out how to remove the clamps. As mentioned, at least PEX is easier to work with than copper (no soldering).

Here's the overall installation. The leaking pipe is part of the hot water circuit and is the section that goes straight up to the ceiling and has a slight bend away from the wall to connect to the copper near the yellow natural gas line. I think the bend starts after the leak, but will take another look later:

 

[Scuba Steve]

Kitek is orange normally, that is not it. Super strange leak point maybe a manufacturer defect.

Sent from the future

 

[Soulcatcher668]

The safest way for you to remove the compression rings is a dremel tool with a cutting disc.
You could also use a hack saw or an angle grinder if you are very careful.
The elbows can be reused if you do not damage them in removal.

You will need the correct size crimping tool to install the new compression rings.

It looks like you can get away with just replacing the vertical section.
Once you have removed the pipe, take a section with you to HD so you make sure you get the correct sizes of pipe compression ring and tool.
Pick up extra as it is good to have around for just such emergencies.

Are there any nicks at the leak point? Could you give us a closeup of the leak point?

 

[Ash]

I think those are the crush-type crimp rings, which would be a beetch to remove. There's probably a special tool to remove those. A dremel with a cutting wheel would work, but it would be easier to just cut the PEX shorter and replace the entire elbow joint. I wouldn't try to re-use the elbows; they're cheap and it's just not worth the effort.

 

[GreyGhost]

Rodents love to eat pex. That is going to become a major issue. Strange place for rodents and you can see the teeth marks though. I am going with defect.

 

[Relax]

The safest way for you to remove the compression rings is a dremel tool with a cutting disc.
You could also use a hack saw or an angle grinder if you are very careful.
The elbows can be reused if you do not damage them in removal.

You will need the correct size crimping tool to install the new compression rings.

It looks like you can get away with just replacing the vertical section.
Once you have removed the pipe, take a section with you to HD so you make sure you get the correct sizes of pipe compression ring and tool.
Pick up extra as it is good to have around for just such emergencies.

Are there any nicks at the leak point? Could you give us a closeup of the leak point?

My main concern is removing the clamp from the connection to the copper, as I really don't want to have to hire someone to solder off/on a new copper connection (a man's got to know his limitations).

I didn't notice any major nicks, rodent bites, or anything else, just a pinhole spray once I turned the water back on.

 

[mimico_polak]

Replace the longes section of pipe you can access. The pinhole leak is to the OUTSIDE of the line…no telling how much of it is worn down in and around the leak or how far on the INSIDE of the line.

 

[GreyGhost]

My main concern is removing the clamp from the connection to the copper, as I really don't want to have to hire someone to solder off/on a new copper connection (a man's got to know his limitations).

I didn't notice any major nicks, rodent bites, or anything else, just a pinhole spray once I turned the water back on.

If it makes you feel any better, the "plumber" that installed it was a two-bit hack. Boogers of solder everywhere, didn't wash off the flux so your pipe is corroding, etc. It's hard to do worse, at least you care about the job, the plumber obviously didn't.

Dremel or bolt cutters to pop the ring. Wrap with a rag soaked in boiling water to soften the pex if it doesn't want to pull off. Little force on the existing fittings and very little chance of damaging them this way.

 

[Mad Mike]

Awesome. Nice to wake up to some replies since Reliance isn't showing up until "sometime between 1-5" today.

@Mad Mike - Here's a couple of adjoining pipes that I could get a clear pic of the markings, don't see any of the ones you mentioned. In any case, if I had to replace everything, I think it's only about 25 ft total PEX plus the clamps until it joins to copper. Can I reuse the elbows, or are they "one-time use" Now to figure out how to remove the clamps. As mentioned, at least PEX is easier to work with than copper (no soldering).

That install looks not terrible, but I don't think the average plumber would put a pic of that work in his scrapbook.

If you replace the PEX, I'd do 2 things:

1) No Elbows. Get the proper bend support brackets (you will need 5 of them $2.50 each). They eliminate elbows which reduces failure points and increases water pressure. They nail to your backer board and make sure you don't overbend the radius. The radius at the top connection should be supported, you should strap across the joists do you have a nailing surface for the bend bracket.

2) Get rid of those galvanized EMT conduit clamps - they are for wire conduit. Use proper plastic saddle clamps. $1.

If it's leaking there, it could be due to improper radius. You can't go less than 7" on 3/4" PEX, and any bend that close to a fitting should be supported.

 

[Soulcatcher668]

My main concern is removing the clamp from the connection to the copper, as I really don't want to have to hire someone to solder off/on a new copper connection (a man's got to know his limitations).

I didn't notice any major nicks, rodent bites, or anything else, just a pinhole spray once I turned the water back on.

You will be fine.

Take your time. If you are worried about slipping and damaging the copper, wrap the copper in a bunch of layers of duct tape.