tankless coil

molly_3

Once removed from the boiler, the old coil LOOKS beautiful, spankin' brandy-new-like. You know those "misters" that come on at the grocery store in the produce section to refresh the broccoli and lettuce... that's the effect you get once pressure tested out in the middle of the room. The chlorine thing has me thinking.You can't smell or taste ANY in the water. That's not to say it's not there. By law, the municipality must furnish a water quality report to all of the users at least once a year. I don't live in that precinct so I don't have a copy. I'm sure it's readily available though. I do know that these folks are at the end of the line on their system and who knows what they have out in the street for a main. It may be ductile iron, asbestos, or galvanized.

molly_3

Good weekend to all. We have a customer who has a Peerless WBV boiler with tankless coil, (a very common set up in this area). She goes through one coil a year due to pin hole leaks that lead to over filling of the boiler. You can almost set your calendar by it. Each time there have been multiple pin holes in the coil. She is on a municipal water system, that is supposedly the proper ph etc. I can't imagine it's a manufacturing problem as 3 years have gone by in between dates of manufacture. She's to the point she wants to put in an electric water heater. (Yuck!) We'd like to solve this mystery and make it right. Electrolysis maybe? How would you check for that? I don't know. Help?

Unknown

The Peerless WBV and coil

are very common here on Long Island also . I got one under my stairs . Where are you located ?

We've been installing this type of system for years and the coils hardly ever give us problems . Maybe it's the high chlorine content from the city water ? Could be the same reason why my neighbor is on his 4th Phase 3 indirect .

I would agree with you that it's not a manufacturing problem . What does the coil look like internally when you rip it out ? Did anyone ever take a water sample to be tested ? Good question about how to find if it's electrolysis . Sorry I don't have any good advice , hope you find the solution .

Firedragon_4

It's the pressure on that sand bar!

LI has some ferocious high city water pressure conditions to compensate for the antiquated, undersized and delapitated systems.

Get the pressure below 75 psi and watch what happens.

High water pressure beats the daylights out of all DHW systems.

Mark Eatherton1

Possible causes...

It could be the Alum thats used in the water treatment to coagulate smaller particles to a large enough target to be filtered out. Alum, a member of the aluminum family, will precipitate out onto the copper and start a dissimilar metal mix that could result in pin holing in copper.

It could also be the flux that you're using to solder the pipes together with.

Lastly, it could be hydraulic erosion corrosion. The finest example of HEC I can think of is the Grand Canyon...

Why not sell her a nice indirect heater tank that would allow you to turn her boiler OFF when all loads are satisfied, thereby saving her fuel, and also giving her more hourly hot water than she'll know what to do with?

Don't lose the sale because of "replacement" mentality. Address the problem, and make a better customer out of her. Think outside of the "thats whats there, replace whats there" box.

JM$0.02W

ME

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Mark Eatherton1

By the way...

does she have a sodium ion exchange water softner? Thats one I forgot to mention...

ME

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molly_3

I've already talked to her about pressure maybe being an issue as it's 90psi. Thanks for your input, even though I knew the pressure was high, I didn't know for sure if it could be a factor on the pin holing problem.

Unknown

Yes , in some towns

like Jericho and Rocky Point we see pressure above 100 psi. in every home . Jercho homes in particular come with a Federal boiler with coil , and the majority of them lasted for decades . I checked my neigbors pressure , he's at 75 psi . I think it's the water content thats doing in his indirects . He kept a sample from the last one , I'll ask if he got it tested .

molly_3

I thought that looking into electrolysis WAS "thinking outside the box"(see original post). It may not be the cause of my pin hole woes, but I thought I'd come here, an internet forum swarming with heating gurus, older and much wiser than myself, for advice as to how to test for such a condition.I'm open to any and all suggestions, advice, ideas as how to solve the pin hole question.

I want to address the problem not tinker around it. I want the cause eliminated before adding anymore new equipment. We didn't do the original install. We inherited this account last year. I'd love to upgrade domestic water to an indirect. It's an obvious upgrade to a coil. It's pretty much standard on all of OUR new or replacement installations. However, how clever am I going to look to the customer after I sell her a $2,000 upgrade, only to have to return one year from now to replace the indirect due to pin hoes in THAT coil.

I've had some good support from quite a few men I admire and respect on this forum and others. I've never been pigeonholed as a parts changer. Never been accused of the " it's what's there, replace what's there mentality".

Friday afternoon 3:00pm, 80 year old single lady, coil in stock (major courtesy to the customer if you ask me), what would YOU do?

I've been a visitor here and other forums for a couple of years. I'm well aware of your qualifications. A guru, yourself. Many people listen when you speak. Professionally, we have the utmost respect for you. That's why I take it personally when you accuse me of "replacement mentality", a lowly parts changer. Not only do I strive to look for answers "outside the box" my whole lifestyle is lived "outside the box". I would not blindly pass judgment on your professional practices Mr. Eatherton. Though I agree with your position on parts replacement, I do not agree with you're inference. Now back to my question about this pesky pin hole issue...

Firedragon_4

Molly, may I suggest

you contact Bob Suffredini at www.tfi-everhot.com

He is the co-author of our book 'The Hot Water Handbook' (www.FiredragonEnt.com) and is a true expert on tanklesses (Everhot) and other water heaters and knows the LI market well. In addition, his firm makes and manufactures all types of DHW heaters in all kinds of materials and may suggest something for that particular locale.

Regretfully, no one in this business has all the answers, I for one keep asking questions.

Rather than jeopordize an account it's best to ask 'the man who knows'. Let us know how you make out and keep pluggin!

tommyoil

when you insert the coil into the block

is there ANY chance that the copper of the coil is touching the iron of the boiler block anywhere along the way???

Bruce M.

What is the complete model WBV-?

What nozzle is in the burner and what nozzle is specified by Peerless? Where were the new tankless coils obtained from? Peerless or aftermarket?

Mark Eatherton1

Molly...

Sorry if I offended you. The comment was not directed at you persoanlly, but at OUR industry as a whole. The fact that you are here asking questions and seeking answers puts you head and shoulders above your competition.

As for testing for electrolysis, I don't not know of an easy way to do so, however, electrolysis always attacks the lesser noble metal in the aquaioues solution. Copper would be the more noble metal in this case, so I seriously doubt it's an electrolysis situation.

Please accept my appologies if I offended you personnally. I do not know you personally, and even if I did I would not judge you.

ME

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Unknown

Yes

I can't speak for Molly , but most of the coils we get nowaydays come a little bent . You have to maneuver the coil plate to make it straighten out , but it don't work too good . What happens if the coil is touching the iron ?

Larry Weingarten

two sources...

that come to mind are http://www.nace.org/nace/index.asp the National Association of Corrosion Engineers and http://64.90.169.191/applications/plumbing/ the Copper Development Association. Between these two there is an answer. There are various things that can cause copper to leak. I'd start with the CDA and then locate a corrosion engineer if needed. Possibly the manufacturer would like to have a look at a failed unit also. Hope that helps.
Yours, Larry

molly_3

hhhhhhmmmmmmmm, that's a good question? I suppose it's a good possibility. Like Ron stated, most coils are bent when we get the too. Diddo to Ron's question about what happens when the coil touches the cast?

molly_3

Thanks for the apology/ clarification and the helpful and interesting information. Please accept my apology for going on a good ol' long rant.

molly_3

It's a 3 section. I don't remember what nozzle is in it, but rest assured it's the make, size and angle that is specified by peerless. Which fire rating it's set at, I'm not sure. I'd have to return to the job to refresh my mind. It's been a couple of months since the c/s. The original coil was replaced by an Everhot coil. That coil was most recently replaced by a coil that was "purged" from a Peerless boiler on late Friday afternoon.

molly_3

thanks for the suggestion nm

Mark Eatherton1

No problem...

Thanks for staying and contributing. Hopefully EVERYONE will learn from your experience. THe reason I asked about a water softener is that sodium ion exchange softeners are HELL on copper pipes, especially in situations where the velocity is high and the water is hot.

Soft water carries a higher concentration of 02, and doesn't allow a protective patina to be set, and allows the copper to be exposed to aggressive conditions much easier. I've had to replace whole DHW distribution systems in hotels due to softeners taking water to ZERO grains of hardness before. Sodium soft water is also hard on peoples pipes...

Thanks for staying Molly. Its great to see women involved in our field. We need ALL the help we can get.

I've had numerous female students, and they've all been some of the sharpest people I've met. You are a fine example.

ME

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Mark Eatherton1

Other than abrasion...

from the copper expanding and contracting and sawing holes through the coil, I don't see it as being a problem. Disimilar mixes are done in closed loop heating systems on a daily basis with no appreciable consequences. As I stated before, in true dielectic conditions, the lesser of the two noble metals suffers material loss (steel in this case).

ME

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molly_3

Though there's no water softener on the system. That info on the extra o2 in softened water aiding in corrosion is handy and interesting to know. As there are many other homes with the exact boiler/coil setup on the same water supply, I'm thinking it just can't be the condition of the water. There's also absolutely no corrosion happening anywhere else in the all copper domestic system. Do you think it could be possible an incorrectly wired ground connected to the plumbing somewhere is going to ground through the boiler water to the boiler block, somehow, causing the pin holes that way, or vise versa? After all the coil and block are separated by a rubber gasket that could insulate one from the other thus creating a chance for voltage drop (for lack of a more correct term on my part). I know the two are mechanically connected be steel bolts, so maybe that blows my kooky theory out of the water. Or maybe your lesson on lesser noble metals would apply, and my theory is total kaka. One reason why I ask, though not an electrician, I can see red flags that tell me someone other than a licensed electrician did the wiring on the boiler/powerventer. Red, last time I checked shouldn't be used for ground wire.

molly_3

One other thing, someone recommended placing a siliphos(sp?) cartridge on the inlet side of the coil. I guess it coats the inside of the coil with a layer of food grade silicone creating a barrier. Does this sound like a worth while effort or if it even works is it "tinkering around the problem"?

Ted Robinson

Leaking Hot water coils

I am also on NY City water and in the last year I have replaced four different domestic horizontal hot water pipe runs for pin hole leaks. Then I found the boiler was flooding so I discontinued using the hot water coil in the oil steam boiler. Now the boiler has a (temporarity plugged) steam leak as well.
Is there something wrong with the public water?
T. Robinson

Kyle Kubs

electrolosis

Hey Molly, - You say "supposedly" the ph of the water is correct... I would recommend testing it - even draw a sample from in the boiler water itself - you just never know... After that my first thought went to a water softener as well but you say there is none. So I'm left at electrolosis as well. My welding experience tells me that being the lesser or greater of noble metals does not matter when there is electrical current running through the metal. Check the boiler casing itself as well as different parts like the heat exchanger and the copper pipes for any electrical current - test both a/c and d/c - just a simple voltmeter is needed.

Good luck
Kyle Kubs

Mark Eatherton1

Easy enought to test for...

First, look for dielectric unions. If they're there, check for voltage on either side of the union for AC and DC voltage. Check to earth ground (incoming metal water pipe)

If you see any substantial voltage, its NOT a good thing. You need to find the source, and eliminate it. Look at everything electrical in the vacinity including but not limited to improperly grounded appliances, telephones. swamp coolers, dryers, conduit in contact with heating pipes, and on and on...

As for metal loss, I'd have to defer to an expert in cathodic and anodic metal transfer, of which I am not an expert.

Something to think about tho.

I did see some really strange crystaline like growth inside of a used cast iron boiler once. We put it into service as a snowmelt boiler. Glycol corrosion inhibitors gave me a feeling of confidence (w/corrosion inhibitors)

Let us know if you find any spare volts laying around:-)

ME

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