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Help with a TT indirect water tank...

Javelin
Javelin Member Posts: 131
Heating Pros,

A little less than 3 years ago, I put in a new TT Prestige boiler with Smart series indirect fired hot water tank. The other day, I was in the basement, and notices some corrosion/build-up, and also evidence that the pressure relief valve has been discharging some water.

I also noticed at the bottom of the tank, where the tank walls meet the black plastic collar, there are some bubbles that appear (at least while it's heating).

So my questions - how bad is this (seems pretty bad). Everything still seems to work just fine, is it immediately unsafe in any way? Is there a fix? Looks like it has a residential Lifetime warranty from TT?

Any advice/direction would be very welcome.

Corrosion at top:
http://javelindesign.com/jobs/tt/top.jpg

Bubbles at bottom:
http://javelindesign.com/jobs/tt/bottom.jpg

Thanks!

Jay
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Comments

  • kcopp
    kcopp Member Posts: 3,821
    A couple things....
    Did you use the special pipe dope they give you for the connections to the tank?
    Is this on City water and if so two things. Is there a check valve/ backflow preventer on the water main and if so is there a potable water expansion tank on the system?
    The drip on the top could be showing up on the bottom....
    Is that PVC on the T&P valve drain?

    Jean-David Beyer
  • SWEI
    SWEI Member Posts: 7,356
    Definitely PVC on something there, but I can't quite tell if it's a T&P or a TMV. Either way, at the bottom of the brass portion there is a coupler which is doing the actual corroding. That looks like a machined, pre-galvanized coupling -- is it by any chance an RMC (electrical) fitting? Be aware that the threads on galvanized fittings and nipples cut through the galvanizing and so the ends will suffer when exposed to oxygen or chlorine. I would use a stainless coupling there, and as @kcopp mentioned, you need to use Loctite (which they provide) on the tank side of the coupling.
  • Bob Bona_4
    Bob Bona_4 Member Posts: 2,083
    edited August 2016
    Been installing TT for just about 28 yrs. The "coupling" in pic is stainless, it's a stub provided by TT. It's hit or miss on the joint integrity on these things. Tolerances between Asian brass vs. TT machining can be a problem. I had always used white teflon/dope. A few years ago TT started to provide a tiny tube of Loctite with the tanks. Dutifully I initially used it, thinking they've recognized the occasional leak point. Still had leakers. After a long exasperated convo with my rep, he recommended using Blue Monster teflon tape (which I already starting using about 6 yrs ago on joints) with dope over it. (As I've done as well - megaloc is my go-to).

    Making sure mating threads are ok,4-5 wraps of tape, coat with dope, and things seem to be working out well on the tanks I've installed since then.

    I'd wire brush off corrosion asap and redo the joint/change the fitting. I'm fairly confident TT won't be warranting anything.
    billtwocase
  • SWEI
    SWEI Member Posts: 7,356
    So the smaller tanks have female fittings?
  • Bob Bona_4
    Bob Bona_4 Member Posts: 2,083
    edited August 2016
    60s and under have 2-3/4 npt stainless stubs and one 3/4 ips stub you see in pic. That's intended for a recirc line or the T&P. Non recirc applications, I plug it with brass, put the T&P on a brass T on the hot outlet.

    80s and up have 3-1 1/2 stainless npt stubs. I may put the XL40 on a brass reducer on the recirc stub or on whatever reducing brass T I use on the hot outlet. That's usually a height restriction desicion.
    SWEI
  • Javelin
    Javelin Member Posts: 131
    Thank you all, sorry for the delayed response - was away last week. Here are some further away photos:

    http://javelindesign.com/jobs/tt/away1.jpg

    http://javelindesign.com/jobs/tt/away2.jpg

    To answer questions, I did use standard teflon tape on the threads, and yes, there is a DHW expansion tank with check valve (see away2.jpg above).

    Bob, I'll take your suggestion and unhook, clean threads and use Blue Monster (if I can find it) and dope.

    Anything else I should do? Bob, you mention that you don't think TT would warranty a replacement? Why not if it's failing? Or if I clean this up and re-work it, is it really just aesthetic and it could last for many more years? Since this indirect doesn't really "do" anything, I was thinking it's the component that would last the longest.

    Thank you all!

    Jay
  • Javelin
    Javelin Member Posts: 131
    One more question... even if the threads are not making good contact, what would be causing the T&P valve to pop? At the bottom of the PVC discharge, there is evidence that it's happening fairly regularly. Just a bad valve that I should replace maybe?
  • Zman
    Zman Member Posts: 6,992
    I would start out by fixing the leaks on the top of the tank. The bubbles on the bottom may be from the water running down the inside of the jacket.
    Typically the T&P issue would be a result of a waterlogged domestic expansion tank. You can get a rough idea by tapping the side of the expansion tank.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    kcoppSWEI
  • Zman
    Zman Member Posts: 6,992
    The picture show a tank....
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Javelin
    Javelin Member Posts: 131
    Thanks Zman - I ordered the blue monster teflon tape (should be here Tuesday at latest) and will fix the threads at the T&P valve. As for the expansion tank, I tapped on it, and it sounds very "heavy" - no "tinny/pingy" noise anywhere... just pretty solid.
    Questions if you don't mind:

    1)Does this mean it's probably waterlogged?

    2) Should I order another? or is there any way to fix?

    3) Do these regularly go bad? It's about 4 years old..

    Thanks,

    Jay
  • delta T
    delta T Member Posts: 860
    1. If you do not get any "ping" noise then yes the tank is probably water logged.

    2. On of two things has happened to cause the tank to waterlog. Either the air has been let out, or there is a hole in the diaphragm. In the former case you can remove the tank from the system (BE VERY CAREFUL IT WILL BE HEAVY!!!!) and try to replace the stem on the schrader valve and pump it up with some air (should be set at your house's static pressure ~50-60 PSI typically) then reinstall. If the Diphragm has a hole in it the tank is shot. If it were mine I wouldn't even bother with it and I would just replace the expansion tank.

    3. 4 years seems like a short life for an expansion tank, but that is going to depend on water quality. I usually see between 6-8 years on average for DHW expansion tanks where I am at.

    As a side note, I ALWAYS replace the relief valve if I am replacing a waterlogged expansion tank. They are not very expensive and once they have been leaking like that I find that they continue to do so regardless of whether or not the expansion tank has been replaced. I have seen a couple that due to them leaking very slowly over many years are so corroded and stuck that I doubt they would help much if there were ever an over-pressure situation. When you replace the expansion tank please re-pipe the PVC discharge in copper. It is much much safer that way. If the relief valve ever pops and lets out a huge surge of high pressure steam and water at 200+ degrees it will cut through the PVC like butter.

    TT will not warranty anything here, there is not a problem with the tank, there is a problem with the initial installation. My guess is that is how they will view it.

    Bob Bona_4SWEIIronman
  • Ironman
    Ironman Member Posts: 6,576
    It appears there's a leak on the union on the hot side.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    Where I live, you cannot use PVC at the discharge of a P/T relief valve. That is not your problem now, but if that valve needs to release due to over temperature, it could melt that PVC.
  • Javelin
    Javelin Member Posts: 131
    Thank you all for your help. I pull out the old pressure relief tank - it was VERY waterlogged and heavy.. Replaced it with a brand new one.. From what I've read, I am supposed to charge the air pressure in the tank to match that of the house water supply pressure (in my case 80psi from Philadelphia Water Department). I know that probably sounds high, but I live in a big old dump of a 3 story house and actually have 1.25" incoming supply from the street, so maybe that's why it's higher?

    I think that's actually the problem, I don't remember charging the expansion tank when I first put it in... so it was probably charged at 40psi from the factory, but really needed to be 80... maybe that's the reason for the pre-mature failure?

    I'll go ahead and order another T&P valve... I guess I should replace that nipple under it too that's all mucked up?

    Is there any valve in particular? I believe the one that's on there now is:

    http://www.supplyhouse.com/Watts-0556002-LFLL100XL-3-4-Lead-Free-Extended-Shank-T-P-Relief-Valve

    And, yes, point taken.. I will replace the discharge with copper pipe per your suggestions.

    Please let me know about the valve and I'll replace in the coming days.

    Thanks!

    Jay
  • Javelin
    Javelin Member Posts: 131
    edited August 2016
    Sorry.. one more follow up.. If I'm going to replace the nipple under the T&P valve, I think the one now is stainless steel??? Can I just use a normal brass 3/4" nipple? Or is there a reason it's Stainless steel from Triangle Tube?
  • Bob Bona_4
    Bob Bona_4 Member Posts: 2,083
    It's not a nipple, its a stainless coupler welded to the tank. I usually put the T/P on the hot outlet, on a brass T, and plug off that third tap that your T/P is on, if no recirc line. I don't want to mess with that tap if I don't have to; you can see how thin the material is. If the T/P needs changing etc, I'd rather deal with a replaceable brass T if it came to it. I feel it's a better serviceable joint there.
  • Javelin
    Javelin Member Posts: 131
    Bob, thanks, but I think that's bad news for me then.. The leak is coming from the bottom of that stainless coupler - see pic:

    http://javelindesign.com/jobs/tt/leak.jpg

    What can I do in this instance? If that coupler is in fact welded to the interior tank, am I in big trouble?
  • Bob Bona_4
    Bob Bona_4 Member Posts: 2,083
    edited August 2016
    Boy that's looking ugly. Seems like that ss coupler is bulging out too. Possible crack from t/p too tight? I'd carefully verify that puddle of water source, if it's travelling down from the t/p joint or indeed from the coupler. I'd cut away the plastic escutcheon or pull it up to get a closer look at bottom. Wire brush all better if you can, look for hairline cracking on coupler.
    delta T
  • Javelin
    Javelin Member Posts: 131
    Bob,

    I've narrowed down the problem on my Triangle Tube Smart 40 indirect tank.. There appears to be a microscopic fissure/leak in the stainless steel nipple that comes out of the tank to the PTRV valve.

    Any thought? Is there some sort of tape I can wrap around it to prevent future leaks?

    The expansion tank has been replaced and a new T&PRV valve is on order (to be replaced Monday).

    You can see the leak - mid-nipple at:

    http://www.javelindesign.com/jobs/tt/leak1.jpg

    Any advice would be VERY welcome!

    Best,
    Jay
  • SWEI
    SWEI Member Posts: 7,356
    Just to be clear -- this is a male NPT 'half nipple' protruding from the tank? Is there enough room to cut and re-thread it? You'd need space for a pipe wrench or some kind of good grip below the threader.
    margsuarez
  • Javelin
    Javelin Member Posts: 131
    Thanks SWEI,

    Yes, this is the male half-nipple coming out of the TT indirect tank.. The one that's meant to hook up to the T&P valve... Looks like about 2" from the tank side up to the leak in the nipple... Seems like it might be enough to cut and rethread right? If I call a real plumber to do it?

    Why would this happen though?... wouldn't this be considered a flaw in the tank? It's less than 3 years old.

    See photos for more clarity...

    http://www.javelindesign.com/jobs/tt/far.jpg

    http://www.javelindesign.com/jobs/tt/close.jpg

    THANK YOU!

    Jay
  • Javelin
    Javelin Member Posts: 131
    SWEI,

    One more thought, I'm going to replace the T&P valve too and since the nipple is a FEMALE thread, would it be smart to just try and use a bunch of dope/tape on the T&P valve? Maybe that would be enough to clog the hole from the inside?

    Do plumber usually have a tool that could rethread the INSIDE/FEMALE like this???

    Thanks,

    Jay

    PS - Here's the original stem before I installed anything back when it was new:

    http://www.javelindesign.com/jobs/tt/original.jpg
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,217
    I would hire a professional welder to come out and either weld the hole shut or weld a new nipple on.
    Ironman
  • Ironman
    Ironman Member Posts: 6,576
    I don't know if a standard pipe tap would do stainless. I agree with Harvey that welding might be the better option.

    Is the tank still under warranty?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • SWEI
    SWEI Member Posts: 7,356
    I was on the fence about adding "Get an experienced TIG welder out there" as another option.
  • I'd call the factory to find out:

    a) Has this ever happened before?

    b) The remedy, i.e. can that half-nipple be removed or is it welded to the tank.
    Often wrong, never in doubt.
  • Gordy
    Gordy Member Posts: 9,514
    edited August 2016
    I love welding stainless....tig most deffinetly.
  • SWEI
    SWEI Member Posts: 7,356
    edited August 2016
    I dabble here and there, but I know guys who can stitch 28ga SS sheet without a backer and I am humbled.

    I'm confused again. Is the female "nipple" actually a coupler mated to a pipe with a male threaded end which protrudes from the tank?
  • Javelin
    Javelin Member Posts: 131
    Ok.. so it looks like I should find a welder in the Philadelphia area who might be interested.. Anyone know anyone? I would THINK this should be under warranty though with the tank.. I think TT says "lifetime" warranty, and I don't see how anything I could have done would have caused this issue right? Just seems like a bad coupler/nipple.

    I'll dig a bit more to confirm that it's actually welded to the tank, but that's what someone (more experienced than me) said earlier I thought.
  • billtwocase
    billtwocase Member Posts: 2,385
    edited August 2016
    Fix all your leaks above the tank, and the wetness on the floor will go away. Also use a new T&P valve when doing the repair
  • Bob Bona_4
    Bob Bona_4 Member Posts: 2,083
    Time to replace tank. Welding...not feasible IMO. You would have to hack open top of tank, find a mobile welder ok with certifying pressure vessels, insurance liability headaches/no coverage if future flood...etc..
  • SWEI
    SWEI Member Posts: 7,356
    If that's really a pinhole, a needle scaler and couple of pops from a TIG gun should close it.

    You could effect a temporary fix using silicone tape.
  • Javelin
    Javelin Member Posts: 131
    Thanks all.. just wanted to give you an update... When I went to replace the T&P valve, it actually made the leak much WORSE, so I then took some silicone tape and wrapped the whole coupling and T&P valve and the leak is barely there now. Not ideal still, but planning on following up on a warranty replacement this week, but at least it's usable in the interim. Thanks for all your help/input - I'll add resolution when I have it in case others have a similar problem.
  • Javelin
    Javelin Member Posts: 131
    Guys, got the new tank an it's in.. Aside from a sensor issue I'm having all looks good.. Just one thing.. the new nipple from the tank that used to be a FEMALE, is now a MALE (just like my T&P valve).. so what do I do? Just get a 3/4 NPT coupling and attach the two? Does it need to be brass or will galvanized work? will the extra height added by the coupling throw off the temperature sensor in the T&P valve? Do they even sell FEMALE T&P valves?

    Thanks! almost there!
  • SWEI
    SWEI Member Posts: 7,356
    T&P valve needs an 8" probe (Watts 100XL-8, Wilkins TP1100A-8C-150C, Cash-Acme NCLX-8).
  • Javelin
    Javelin Member Posts: 131
    Thanks again SWEI, what about material for the coupling... The stem coming out of the tank is stainless steel I think... I saw they make ss couplings, and also brass... I have a temporary galvanized on there, but don't think that should stay long term.. right?
  • SWEI
    SWEI Member Posts: 7,356
    Galvanized meets code, but threading removes the galvanizing so it will rust at the edges. I'd use either a brass or stainless coupling. IME it takes both tape and dope to make reliable stainless to stainless joints.
    Ironman
  • Javelin
    Javelin Member Posts: 131
    Plumbing Pros,

    So Triangle tube replaced my hot water tank last year and all was looking great for a while.. Bone dry, clean, etc. But the other day I looked at it and saw this... All this muck around the hot water nipple... Now, in the earlier version they had a FEMALE nipple welded to the inner thank, now at least it's a MALE as you can see. Did I do something wrong here? What could be causing this? I'm guessing I should disassemble and clean up now before it gets worse? Just trying to find the underlying problem. Could the hot water be too hot or something? I am in Philadelphia and we have pretty HARD water too I think - is that an issue?

    Thanks for any guidance you all have!

    Jay



  • Bob Bona_4
    Bob Bona_4 Member Posts: 2,083
    Get rid of those female adapters. That's one source of the leak. Get 2 brass couplers, and 2 copper male adapters. Sweat in a short section of 3/4 copper to the male adapters. Use high quality teflon such as Monster tape on the adapters and the TT stubs, 5 turns. Coat them with pipe dope- Megaloc works well- and re assemble. I'd ditch the unions. Just another leak point with very little return. Brass couplers won't spread like female adapters do.

    Knowing your water chemistry is always important.
    ZmanGordy
  • Zman
    Zman Member Posts: 6,992
    Bob has got you pointed the right way.
    These products cost quite a bit but work great for all of these types of water heater and boiler connections http://www.supplyhouse.com/Elkhart-56686-1-CxF-Union-Lead-Free
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein