# Weil-Mclean and their aluminum heat exchanger vs Veissman's SS



## markb (Jun 11, 2009)

What is the deal with Weil-Mclean only using aluminum heat exchangers on their Ultra (expensive) 3 condensating HE boilers? Any specific reason? Any problems people have faced with the heat exchanger in the past? Should I worry?

Trying to decided whether to install Weil-Mclean Ultra 3 HE or Veissman Vitodens 200-w. I think I want the Weil-Mclean, but the aluminum heat exchanger worries me a bit. Veissman has a SS heat exchanger.


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## RealLivePlumber (Jun 22, 2008)

I understand that WM had issues with the condensate rotting the alum. heat exchanger. I was told that they have resolved the issue. 

But, it just does not seem right.


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## ZL700 (Dec 8, 2009)

RealLivePlumber said:


> I understand that WM had issues with the condensate rotting the alum. heat exchanger. I was told that they have resolved the issue.
> 
> But, it just does not seem right.


Yes they did, they installed a stainless cup in the bottom outlet of the condenstate collection cup.

There are many quality aluminum and SS boilers out there, W/M, not being the only alum, take Buderus for example.

Whether alum or various SS grades, 316L, 319L, 426..... both have there different potential problems. For instance SS has a problem dealing with high chorides, while aluminum is susceptible to failure due to PH.

Both systems requires careful application consideration, proper installation and service.


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## dodgefreak8 (Apr 3, 2010)

I like the lochinvar knights. SS heat exchanger and an all around great product


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## Ishmael (Dec 9, 2009)

dodgefreak8 said:


> I like the lochinvar knights. SS heat exchanger and an all around great product


 
I installed my first Knight a couple of months ago...nice little unit.

I installed a Weil-McLain Ultra (80) in my own house about 5 or 6 years ago - so far so good. I've done about a half dozen of them, and have had only one (major) problem so far. I got a couple hard lock-outs on one of them (it would overheat and shut down). I'd have to go over and reset it. The house had a lot of the Wirsbo Quik-Trak with the 5/16" pex tubing, so at first I thought there must be some stubborn air in the lines that wouldn't purge out. 

The first time I went, I figured this is a good time to fill the system with the aluminum safe antifreeze ($$), so I did that at the time. The second time I went over there, I purged/pumped the system through a 5 gallon bucket; when I was done, there was a layer of fine sand on the bottom of the bucket. After talking it over with their tech line, it was detemined it was sand left over from the aluminum casting process. The block goes through a vibrating conveyor that is supposed to shake all the sand out. Apparently, that step was either skipped or just plain failed with this particular unit. I hoped that was the last of the problems, but there was yet another hard lock-out. Back again to purge not air, but sand from the system. This time I brought a Cuno whole-house filter and pumped all the system water/antifreeze through that. I couldn't believe how much sand there was. That was almost two years ago and it hasn't been a problem since.


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