Unica vs Laars - Indirect Water Heater

bmar750

I'm looking to replace my indirect water heater. Which is better Laars or Unica for residential house or neither? Looking for a quality unit that will last a long time as my current water heater is 34 yrs but is starting to drip at the connection points. Thoughts?

mattmia2

Look at your water chemistry and what the manufacturers recommend and make sure your water is within those specs. There are lots of good options. Make sure the HX has enough surface area to make the amount of hot water you need.

bmar750

Thanks.  Any difference in quality between manufacturers?

Pulse

Laars are just rebranded Bradford White, you get 444 stainless tank and HE. 2" of insulation

Utica you get 316L tank and probably a 316L HE. I did notice they have 2.25" of insulation which is the best iv seen, everyone else has 2"

bmar750

Thanks for the feedback!  I did see what you called out as differences (ss and insulation).  Not sure if it makes much difference between the brands to go one way or the other since both come in at the same price.  I think it comes down to who do will do a better job and stand behind their work down the road.

mattmia2

Different ss alloys do better with different water chemistries. one isn't necessarily universally better than the other. HTP makes their hx out of cupranickel with the idea that it will expand and contract with temp change and descake itself. Some other brands have a removable hatch of one form or another to clean out sediment. Some models require an anode despite being SS.

Pulse

mattmia2 said:

Different ss alloys do better with different water chemistries.

Is there a chart or something that has comparison information on different SS? I could not find anything useful.

Larry Weingarten

Hi, For what it's worth, I just did a search at addall.com and came up with this list of possibly relevant books: https://used.addall.com/SuperRare/UsedRare.cgi?title=&author=&title=Corrosion++Stainless+Steels+&keyword=&isbn=&exclude=&binding=Any+Binding&min=&max=&dispCurr=USD&order=PRICE&ordering=ASC&match=Y&timeout=15&store=ABAA&store=Alibris&store=Abebooks&store=AbebooksAU&store=AbebooksDE&store=AbebooksFR&store=AbebooksUK&store=Amazon&store=AmazonCA&store=AmazonUK&store=AmazonDE&store=AmazonFR&store=Antiqbook&store=Biblio&store=BiblioUK&store=Booksandcollectibles&store=Ebay&store=EbayUK&store=LRB&store=ZVAB&via=used

Yours, Larry
ps. NACE has a book on it but it's rather expensive.

hot_rod

In many cases the glass lined tanks are lasting longer.
Looks at your chloride levels, that seems to be the issue with stainless.

bmar750

Hot Rod - any recommended manufacturers of glass lines indirect heaters?

flat_twin

Bock offers a glass lined indirect with a lifetime warranty for residential applications if you register when it's installed. Two anode rods, large bore hx, heavy gauge tank. Only three years use on our 40 gallon indirect, no problems.

https://www.bockwaterheaters.com/products/indirect-water-heaters.html

hot_rod

I like the Bock, they have a large diameter coil so you can throw a lot of BTUs at them.

I think that tank and coils are sold under a few names.
I've found high chloride water or high ph works best in a glass lined, smooth coil tank.

Here is an example of a coil out of a 50 gallon.
1" connection, 1-1/2" coil.