Leaking Viessman Vitocell 300 (with pics)

meerkat

I'm creating this as a spin-off from my how-to-contact Viessman question/post because the condition of the Vitocell is its own separate subject. This tank was part of a new Viessman install (Vitorond 100 + Vitocell 300) in mid-March 2018. We noticed a rusty water line on the exterior of the Vitocell in late February of this year (2022.)
The other post has the whole contractor-story/warranty issue described. In a nutshell, it's been 3 months and we are still waiting for this issue to be addressed.
https://forum.heatinghelp.com/discussion/188555/real-person-contact-at-viessmann-in-r-i-these-days-stymied
Here are some current pics as of today.
First, two views of the overall system:

meerkat

Three areas where lines of rusty water run down the outside of the tank. Front of tank:


Rear of tank:


Side (this appears to be primarily coming from the inside top of the lid, however:

meerkat

Inside of lid, and inside top of the unit. The photo I took this morning didn't really show where the waterline is, so I took a new pic and added the arrows to indicate how much water is currently sitting there. The lines etc are probably from when the tech mopped/wiped this area when he was here in early March.

meerkat

And finally, the Therm-X-Span tank issue which I discovered this morning when I went to take these pics. The rust blister was NOT there in March, or April, or even three weeks ago. Anyone taking bets on how long it will be before that spot entirely blows out and starts spraying water?

meerkat

@Alan (California Radiant) Forbes mentioned in my other post that the expansion tank failure may have contributed to or caused the problem with the Viessmann indirect. If that's that case, I would suspect that Viessmann would consider that a basis to not honor a warranty claim. However, I'd also suspect that the tech who examined the Viessmann issue in early March should have also checked the expansion tank to make sure that it was working properly.... even though at that time the exterior of the expansion tank looked perfectly fine.
My mind is boggled by this whole scenario. In 40+ years of home ownership, 5 houses all with an oil boiler/indirect tank setup (with at least one expansion tank in the system), we've never had an issue like this either with an expansion tank or an indirect tank.

Btw, as mentioned in my other post, we had our water lab-tested before specifying the Viessmann tank - just to make sure that the chloride and other water component levels would be within Viessmann's water quality guidelines. They were.

heathead

Have you taken the white small cover off their is a access cover under it. It has a gasket and inspection port. Is it leaking from those threads. Could this be a simple gasket or tighten access port?

109A_5

meerkat said:

Btw, as mentioned in my other post, we had our water lab-tested before specifying the Viessmann tank

How is it now 4 years later ???

Vitocell 300, high-alloy stainless steel ? Where is the rust coming from ? Tank housing ? Expansion tank compromised creating rust and too much pressure thus Vitocell 300 failure due to pressure ? Or is it just the Inspection and cleaning opening leaking under that insulation cover? Shouldn't there be a pressure relief valve (T&P valve) on the DHW side, not seeing it ?

Too bad it is a warranty job. I'd just replace the expansion tank and if the leak is from the Inspection and cleaning opening on top of the Vitocell 300 (see manual), secure it better and / or replace the gasket. Better yet, I'd replace the expansion tank immediately, before more damage happens, it is probably out of the manufactures warranty anyway if it is original to that system.

Not too hard to check the expansion tank way before obvious failures. Tap, tap, tap, you could get a hand air pump and a gauge too.

mattmia2

Is the expansion tank on the dhw side or the dh side?

Did you look in around the grommets on the tank to see if it is leaking at any of the connections?

mattmia2

Could the expansion tank leak have been unnoticed and leaking in to the tank around or under the top cover or maybe evaporating on the tank and condensing inside the cover?

meerkat

Just took some additional pictures to go along with my response to the comments.
@109A_5 , we haven't had the water tested since the initial one, because I didn't think we would need to; are owners of these tanks expected or required to continually monitor their water chemistry even if it's from city/public? I can definitely see how people who are on a private well would be doing that anyway, but not for so-called "city water".
Here are some pics of the relief valve area:


There is no dampness at any of the connections/joints that I can see or feel. The rusty-water line is what's running down from the rust blister on the tank. From what I can see, the rust drip on the back side of that first fitting below the tank is because the 'main dripline' pooled there a bit.

There is active seepage around the rust blister.

And yes, the Therm-X-Span is out of warranty; it's only 1 year on these, as I found out yesterday when I checked the XTrol site. As far as I know, the tech who was here in early March did not replace the original expansion tank; he said nothing about doing that (or about anything else he did) and did not provide any paperwork saying what was done. In retrospect, I see that I should have at least asked him to tell me in detail what he did, if he wasn't going to write up any kind of a service ticket listing what was checked and/or done.

hot_rod

Officially the probe on the T&P valve needs to reach into the tank. They do make extended probe versions, up to 8" long.

I'd certainly pop the relief to assure it works, it is the final over-pressurization protection. Be prepared to replace it however, occasionally they do not re-seal when you pop them.

meerkat

@mattmia2 , let me know if these new pics don't answer the questions you asked about the relief valve piping. Would it help to have a pic showing the entire general area of how both expansion tanks are piped?
Good point about the possibility of the water inside the top of the Viessmann coming from the expansion tank. Would that not have been obvious to the tech, back in March, when he began to check (I assumed, lol) all of the accessible fittings on the indirect?
Also, thanks to you and @Alan (California Radiant) Forbes for your further explanations of the
warranty claim process. I admit that I got so irked about the "nothing done for 3 months" situation that I jumped to the conclusion that the contractor had simply punted it to the supply house because he didn't want to bother with the paperwork. So it seems I can't fault him on procedure, although I do still fault him for not following up when weeks and then months went by with no word from the supply house. Obviously the entire world has been dealing with supply chain issues ever since COVID but even that kind of an update would have been useful. Anything's better than 'crickets'.

meerkat

I also want to say that I'm very much aware that techs (in whatever field) aren't exactly fond of homeowners who hang around and 'look over their shoulder' while working. Not only is it a distraction but it gives the impression that the homeowner doesn't trust the tech to be competent. And sad to say, this issue is magnified when the homeowner is a woman.
A tech doesn't know, and probably wouldn't care, that my experience includes not only 2 complete gut-and-remodels but also being the designer, general contractor and 'site manager' of a new build. This means I can hold an intelligent conversation about things like foundations and footings, site drainage, roof runoff management, structural framing/loads, etc etc. But I also know what I don't know, and don't have, which is years of hands-on experience, and far as electrical and plumbing go, that's more important than reams of theory, IMHO. So I leave those two fields to the pros. Sure, I can spot a lousy/lazy plumbing job where pipes aren't pitched correctly or traps are missing or in totally useless places. But I'm not qualified to grab a torch and start sweating copper myself, lol
Because of my background in research, I'm like a ferret whenever I need to figure out the 'why' of something. But I often forget that many people aren't like that, and would rather do a quick fix, move on to the next thing and hope that if their work/guess/fix was incorrect or doesn't hold up over time, someone else will come in and deal with it. In retrospect, I wish I'd watched everything the tech did in March and asked questions, especially when nothing was written up at the end of the service call.

mattmia2

It looks like some of the water might be following that fitting in to the tank jacket. Perhaps from there it is evaporating then condensing on the dome and collecting at the top.

You are going to have to replace the expansion tank anyhow, might as well do that now and see if the indirect tank problem goes away. Set the pressure on the diaphragm to the pressure of your domestic water supply before you connect it.

Alan (California Radiant) Forbes

I also want to say that I'm very much aware that techs (in whatever field) aren't exactly fond of homeowners who hang around and 'look over their shoulder' while working.

There are homeowners who want to watch and learn. Nothing wrong with that. However there are times when I want to be left alone and I will ask the owner to leave.

Officially the probe on the T&P valve needs to reach into the tank. They do make extended probe versions, up to 8" long.

Viessmann includes a relief valve with an 8" probe with the indirect.

The instructions for DHW expansion tanks tell you to install the tank on the cold supply line before going into the indirect as hot water reduces the life of the diaphragm and metal of the tank.
https://www.amtrol.com/wp-content/uploads/2019/02/9015-942-01_19-Thermal-Expansion-Tank-IO.pdf

mattmia2

Take one more picture of the bottom of that tee that comes out of the tank, I think it might be following the bottom of the tee and nipple in to the jacket of the tank.

109A_5

meerkat said:

@109A_5 , we haven't had the water tested since the initial one, because I didn't think we would need to; are owners of these tanks expected or required to continually monitor their water chemistry even if it's from city/public? I can definitely see how people who are on a private well would be doing that anyway, but not for so-called "city water".

If you are going for a warranty claim on the Vitocell 300 you may want data to support your claim and that the water is not the problem, since they conceivably could blame it on the water and deny the claim. Also it is something you can do while you are waiting.

One troubleshooting strategy is to eliminate the things that are NOT the problem, in doing so eventually you will get to the actual problem.

My gut feeling is it is not a water quality issue, the the Inspection and cleaning opening on top of the Vitocell 300 (see manual) is leaking. It may be related to the expansion tank failure or not. There still may be air in the expansion tank even though it is leaking and the diaphragm is probably compromised.

Alan (California Radiant) Forbes

Take one more picture of the bottom of that tee that comes out of the tank, I think it might be following the bottom of the tee and nipple in to the jacket of the tank.

I think that @mattmia2 is on to something. Replace the tank and the leak might go away!

109A_5

meerkat said:

Good point about the possibility of the water inside the top of the Viessmann coming from the expansion tank.

So the looking at the pictures water flows up hill naturally against gravity ? And didn't the Vitocell 300 issue start before the expansion tank leak ?

mattmia2

109A_5 said:

meerkat said:

Good point about the possibility of the water inside the top of the Viessmann coming from the expansion tank.

So the looking at the pictures water flows up naturally against gravity ?

I think it may be evaporating on the hot tank then condensing on the cold cover. There is also capillary action.

Was the water still there after a few days with the top cover off?

109A_5

And didn't the Vitocell 300 issue start before the expansion tank leak ?

mattmia2

109A_5 said:

And didn't the Vitocell 300 issue start before the expansion tank leak ?

Before it was discovered. That doesn't mean it wasn't happening and the attention was put on the tank itself.

109A_5

That's a lot of water if you look at the pic with the blue arrows. And it is coming out everywhere it can. And the expansion tank leak is pretty blatant with that blister and rust trail in the overall system pictures. Again, didn't the Vitocell 300 issue start way, way, way (many Months) before the expansion tank leak ?

Alan (California Radiant) Forbes

@meerkat only noticed the leak recently when I asked her about it, but it could have been leaking long before that. 

hot_rod

personally, I'd relocate the new tank, it really should be on the cold supply. Solve two potential problems, the leak running into the tank, and the tank in the better location.
A Webstone isolation valve while you are at it.

Chlorides more than anything go after stainless, the welds actually. Chloride levels can change and in fact go up in winter times in some areas due to de-icers getting into the aquifers.

meerkat

Sorry for the delay, just got back from taking my car to the repair shop (it's definitely shaping up as One Of Those Weeks )
@mattmia2 , no new water appeared in the top of the Viessmann during the 10 or 12 days that the cover was off. It returned only after the cover was put back on. I waited almost a week to check that, because I didn't want to assume too soon that "everything was fine". So yes, condensation would account for that behavior.
Here's a pic of the underside of that tee just below the expansion tank. Looks and feels 100% dry. No rust residue either.

@Alan (California Radiant) Forbes is correct: I only became aware of the rust problem with the expansion tank yesterday when I went down there to take photos. It definitely wasn't in that (visibly rusting) condition last month.
So here's an additional update. After my somewhat peevish voicemail to the contractor on Friday, followed by an exchange of emails over the weekend, he said on Monday that he would call me this morning (Wednesday) about the situation. Having discovered the expansion tank's condition yesterday, I figured I'd give him that glorious news during that phone call.
When I hadn't heard from him by 3 pm, I emailed him the photo of the expansion tank and asked "If this tank was failing in early March, why wasn't that found? Obviously it now needs to be replaced ASAP!"
Got a phone call from him 10 minutes later, saying that
(a) the warranty was put through the supply house because that's what Viessmann requires,
(b) he submitted all the info to the supply house in March but then completely forgot about it until my voicemail message on Friday,
(c) he called the supply house this morning but as of that moment (3 pm) they had not called him back.
As for the expansion tank, he says that it "has nothing to do with the Viessmann, it's an entirely separate thing." I commented that it certainly is NOT separate physically and thus could be a factor. His response was "One has absolutely nothing to do with the other" and that the expansion tank will be replaced tomorrow morning. Which now brings me to @hot_rod 's suggestion....

meerkat

Should I insist, tomorrow, that the new tank be installed on the cold water inlet instead? If so, it seems that some new piping will be needed, because as you can see here, there's not enough room to put it in the upper section (purple arrow), which leaves only the lower section (blue arrow)

But that maynot work either, as this side view of that same area shows. I'm not sure there is enough clearance (as the cold water is currently run) to put the new tank there either. If so, it'll be a real tight squeeze up against the side of the Viessmann.

You KNOW that the tech is going to plan on just slapping the new tank in the same location as the failed one, rather than modifying that existing cold water line, right? I can hear the cha-chings now about the copper and the extra labor if I insist. Although I will print out that Amtrol PDF about the tank needing to be on the cold line rather than the hot, and say "you guys put it in the wrong spot to begin with." But it's better than having the next tank fail in short order....yeesh.
Speaking of the back of the Viessmann, should I assume that the height of these rusting outer-jacket closures (or whatever they are) indicates how much water is sitting in that area? As you can see, the ones above that level are fine. Didn't really notice the rusting ones until tonight...

Alan (California Radiant) Forbes

If it were me, I'd ask him to put the x-tank where it belongs. Like the instructions say, on the cold line, properly supported. No charge to you.

If the indirect dries out and stops leaking, he just learned an important lesson.

hot_rod

There is an ongoing debate on life expectancy with nipple up or down, but directions are clear on cold supply side and vertical. Maybe located with nothing below, knowing it may agin leak, someday

mattmia2

meerkat said:

Speaking of the back of the Viessmann, should I assume that the height of these rusting outer-jacket closures (or whatever they are) indicates how much water is sitting in that area? As you can see, the ones above that level are fine. Didn't really notice the rusting ones until tonight...

It is wet at those 2 iron ells that are rusty too. they are damp on the outside, they don't rust if they are dry.

meerkat

mattmia2 said:

It is wet at those 2 iron ells that are rusty too. they are damp on the outside, they don't rust if they are dry.

I did notice those ells and they surprised me. That said, I live on Long Island and the general consensus is that "there's no such thing as a dry basement, the only question is how damp does it get." Especially when you've got an unfinished basement and the local geography is heavy rocky clay with a preponderance of underground springs. Don't even get me started on how much money we've had to spend on mitigation.
Previous owners had an illegal apartment in the basement and the drywall and carpeting covered up a multitude of issues. When we gutted the basement we discovered that some genius had even tarred the interior concrete walls behind the drywall, in a misguided, futile, and totally-against-code attempt to make the basement drier.
There is a black iron vent pipe section on the oil tank and that's been fine; it's been that way since we bought this house in 2013. No idea why both the vent and fill pipes weren't done in black iron but are a mix ... don't get me started on that as well, lol

Dave Carpentier

Has that tank been painted ? Is the very bottom edge of the rounded part all rough, like paint covering corrosion ?

meerkat

Dave Carpentier said:

Has that tank been painted ? Is the very bottom edge of the rounded part all rough, like paint covering corrosion ?

Nope, tank is fine. No roughness or corrosion anywhere. The prior owners must have replaced the original one not long before they put the house up for sale in 2013. (ETA: managed to take a pic of the plate: 2002)
One issue it does have is some seepage at the connections. The pic in my previous post was taken in 2018; the pic below was taken this morning. We had some foundation repair work done in the basement in February which left a film of concrete dust on the tank (I shut off the heating system and threw a tarp over the burner and boiler while the work was being done, but no need to cover the tank). I normally keep a rag wrapped around the connections, as in the 2018 pic, but the foundation repair guys must have removed them.

The other idiocy that former owners did was to cover the copper line with cement. We'd been planning to have a new, jacketed line run in early 2020, having seemingly finally found a oil service company with competent techs. Then COVID happened, nobody was doing anything except emergency work, and six months later, that company had gone out of business after 20+ years. Haven't yet found anyone I'd trust to do anything more than a simple tune-up, to be honest. I know in my heart that the lime in the concrete is eating away at that copper line and it's only a matter of time before it fails.

meerkat

New expansion tank installed today. Asked the tech why the bad one wasn't put onto the cold water line. He said "it was the most convenient place, it doesn't really matter." I said, Well the manufacturer thinks it does, because their installation instructions say cold water line only. He said "I can put the new one where the line enters the house." I said, That's on the opposite end of the house, diagonally, at least 50 feet away, too far from the tank. So it went here (pressurized to match the 56 psi house supply before install):


As for any Viessmann-tank news, still nothing from the supply house as of today. But an interesting comment from the tech, when I pointed out those two rusted iron ells. He said "That's because the fitting above them was dripping on them in March, I replaced it but that's why they rusted." Well, at least I now know ONE thing that was done in March.
To his credit, he did say that he wished that he had replaced the expansion tank in March as well.

Alan (California Radiant) Forbes

Nicely done!

Now, with the leaking x-tank out of the equation, let's see if the indirect continues to show water.

hot_rod

It does seem odd that rust would be showing from a stainless steel leak.

EBEBRATT-Ed

As far as I know sweat copper is not allowed on an oil tank or oil piping. Brazing is allowed however, at least brazing used to be ok. Not sure now after reading NFPA 31

Tank vent and fill should be black pipe threaded or Mega Press. Maybe copper with propress G is allowed. Not sure.

What do you think @STEVEusaPA ?

mattmia2

hot_rod said:

It does seem odd that rust would be showing from a stainless steel leak.

I think the rust is from the jacket

Side note, I learned the hard way that a superstore has a plastic jacket that looks like painted steel.

GGross

@mattmia2

From the specification sheet on that viessmann unit
" white epoxy-coated sheet steel casing"
https://www.vitoteam.com/Pages/eng/sub/submittal.php?d2=EVIB-42&a1=1xPRVT-9677934&

gennady

At the top of the vitocell, under the foam, there should be an inspection cap. Unscrew it, add teflon and dope, and screw it back tight. leak will be gone.

meerkat

@gennady , I actually had a conversation about the inspection cap area with the tech who was here on Thursday to replace the expansion tank. It's the same tech who was here in March. He spoke about that area being a source of leakage on many indirects, by which I assume(d) that he had inspected it in March and addressed any problem that he either found or suspected.
As a further update to the warranty situation, I emailed the contractor this morning to ask whether he had any response from the supply house which he had called on Wednesday morning. Contractor said that he (supply house) spoke to him (contractor) on Friday. When I asked what the supply house guy had told him, the answer was that the supply house guy said they "will start the paperwork on Monday", meaning today.
So the supply house who supposedly received all the pics and info from the contractor 3 1/2 months ago will finally START the warranty "paperwork" process today.
Supposedly.