Hard water + chloramine with tankless water heater

[Thomas Kotwal]

I need a new water heater and I'm considering a tankless (on-demand) due to the long term cost/energy savings and space savings. A local plumber has recommended against it due to the water in town. I think he said the water has chloramine which causes problems with the tankless system. It's also hard water, but I think I can address that with an annual flush with vinegar.

Does that sound right? Is there anything that can be done about chloramine?

Thanks.

 

[Diehard]

I believe there are a lot of considerations you should look into.
I personally, would simply add an Insulation Jacket to my storage tank water heater to save a few bucks, if I really thought the difference amounted to very much.
In case you haven't seen info on the pros and cons of tankless vs tank types, I will try attaching a pretty good list of them. Although I don't fully agree with some of the thoughts included.

 

[Thomas Kotwal]

Thanks. I had seem most of these before, but it's nice to see them well laid out in one place.

Generally, I think the pros of tankless outweigh the cons, although it depends on the actual install cost.

However, in my specific situation, I have this issue of chloramine in the water and I'm wondering if anyone knows if or how that affects the decision.

Thanks again.

 

[Diehard]

Well it's funny that I wasn't aware of the switch from chlorine to chloramine for disinfecting water, in many locations. And I worked for a Water and Wastewater Treatment plant design consultant for about 45 years. But I have been retired for a little over 7 years now and I was in the plumbing group and not the process group.
Myself, I would pose the question to the many instantaneous water heater manufacturers. And the impact, if any on their warranties. If you can get a straight answer from them.

 

[Thomas Kotwal]

Contacting the manufacturers is a great idea. I'll see if I can get a question in by the end of the day, although since I'm currently without hot water and I've got a plumber waiting for an answer, my guess is that I won't get an answer in time.

 

[Diehard]

Get those pots of water on the stove.

So may I assume you've already establish you have sufficient gas or electric to supply the bigger load?

 

[Thomas Kotwal]

The heater is powered by gas and it would be placed right next to where it comes in from the street, so I think it will be fine.

 

[breplum]

Chloramine is not generally a problem with any major tankless brand.
We have had chloramine here in the bay area for well over twenty years.
It is holy hell on rubber, especially the black rubber types.
Do yourself a favor and consider Navien NPE series for your water heater.
The Navien mini-tank and pump are superior.
You will never get an actual return on your investment with high quality/cost tankless.

 

[Thomas Kotwal]

Thanks for the info.

I wonder if I misheard the plumber and the issue is actually with chlorides, not chloramine. Looking at the manuals for both a Navien NPE unit and a Rinnai RUC unit which was recommended to me, the maximum allowable chloride concentration is 250 mg/L (same as ppm). The most recent water quality report for my town shows a chloride concentration of 340 mg/L. Would you expect a problem with that?

A related question: how strict are the manufacturers with the warranties? If I were to have a problem, would they really not honor the warranty due to water quality? Also, the manual (at least for the Rinnai) states that they have to be inspected and serviced annually by a licensed professional to maintain the warranty. Do they really check for service records or something like that before honoring the warranty?

Thank you.

 

[breplum]

The Navien is required to be installed by a licensed plumber and they do ask who the installer was during the warranty registration.
Navien and most mfrs do recommend servicing annually but frankly, that can be related more to mfr's protecting themselves than actual need. However, water hardness/quality plays a big role inside the units and pre-treatment against hard water is one important aspect of that. (Sorry, I know nothing about chlorides).

Navien has had a minor problem with hard water or other source causing slight fouling of the air bleeder on the pump, the result is dribbling of water out of the bleeder. In every case I have known of, Navien sends a new pump with NO questions asked, as long as it is within the 6 yr. parts warranty period. Without regard to the water quality or source.

 

[Thomas Kotwal]

Thanks for the great info.

Despite my strong desire to go with the more efficient tankless unit, I can't justify it with the water quality in my town. With the rebates, the install cost for the tankless is about $1500 higher than standard storage, so it would take 10 years or more to make that back, based on the "yellow-label" estimated annual operating costs. Based on the local water quality, and the advice a local plumber (who is well reviewed and seems knowledgeable on the subject), I have concerns that it will last that long. If I knew it would last 20 years, like some people have reported, then it's a no-brainer. I just don't want to take the chance right now.

The tank I'm going to get has a 10 year warranty, so I'll just have to revisit this then.

Thanks everyone for all the good info.

 

[breplum]

Tank water heater warranties are pro-rated.
SO understand that towards the end, there is hardly any actual value worth the trouble.

 

[Thomas Kotwal]

As I just learned, they aren't all pro-rated. The one that I'm replacing was bought at Home Depot and that one is pro-rated. I've still got a year left on the warranty, so I should be able to get a bit of money back once I bring it in.

The new one that my plumber will install is made by State and if the tank leaks within the 10 year warranty period, they'll replace the whole thing. If part breaks, they'll send me a replacement part. Pretty good deal.

Here's the text from their warranty document:
If the inner tank leaks within the warranty period listed on the data plate label after the original installation, Manufacturer will furnish a new water heater of Manufacturer’s then prevailing comparable model.