Boilers - Aluminum vs. Stainless

k2p2

I am new to this site and very much a novice. My home in Seattle is 10 years old and has an "open" hydronic heating system. Two hot water tanks in garage provide both heating and potable water...water flows to in-wall fan radiators for heat. I've been cautioned that this system is potentially dangerous..and it's noisy with PVC venting.

Friend of mine is suggesting a GB142 boiler with Mega-Stor 53 storage tank. Question: Why do some boilers have aluminum inside and others have stainless steel? I have pex-al-pex tubing..not sure if I have that quite right...that I'm told needs to have a lower pressure than current operation.

Thanks for reading. Also, I need to learn more about all of this. Any ideas for websites dedicated to details about hydronic heating function and set-up?

-Leigh

Paul Pollets

Seattle

Leigh, we prefer stainless steel heat exchangers rather than aluminum, as SS is far more corrosion resistant. Our shop is in Ballard, and we'd be happy to help you. Often, non-barrier Pex was used in the open systems to the wall convectors. That (non-barrier Pex) also plays a role in what system can be used and how a new boiler is piped in.

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Singh_9

Leigh

Some manufacturers use aluminum because of it's greater heat transfer capabilities, and to be able to cast a uniform thickness throughout the heat exchanger.
Both aluminum and stainless steel are vulnerable to corrosion. SS with high levels of chlorine in an open system may also cause premature failure. PH levels should be checked and maintained on both type heat exchangers.

Otherwise the GB142 is a good unit.

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EricAune

You have found it!

This is the best site available. There are some sites that are informational, but most are sales driven and promote a single product.

Check out the many books available here. I have been working in this field for only 15 years, I have not come across written material as useful Dan's books.

P.S.
I do not get paid to say such things, I do feel there are some of the most knowledgeable people frequenting this site.

Peace

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KevinCorr

I agree with Eric. Dan's books on hydronics are the BEST!

CMadatMe

Alum vs Stainless

The easiset was to anwser your question is to look at the table of metals. Stainless is by far a better material. Like the post below alum is used because of it's heat transfer but what it gives longevity. While it's not avail to the rest of the country only the Northeast right now I would look at the Vitodens Boiler from Viessmann. I have a post in the thread on the boiler so I won't go into it here. The biggeset advantage that I didn't state in my thread is 2yr warranty parts, 10 years full on heat exchanger but it's pro-rated and you will never pay more than 50% of it's value after the 15th year for a replacement. Every other manufacture warranty is only 1yr parts and 10yrs on heat exchanger after that you are on you own.

KevinCorr

"...Every other manufacture warranty is only 1yr parts and 10yrs on heat exchanger after that you are on you own..."

You could look into what Energy Kinetics means by "Limited night time Warranty"

I installed a gas fired System 2000 in Seattle about 20 yrs ago which is still going strong and it is steel not stainless, not cast iron. SS is not necessary depending on the design, that is if there is no condensation.

CMadatMe

I thought

we were talking about gas condensing wall hungs on this thread. I don't see a gas boiler on EK site more than 85 percent AFUE

KevinCorr

Yes, their gas boiler is non condensing. It is 86% and afue is only part of the efficiency picture. Since OP is a novice and is shopping for a boiler, why would you limit the information to "gas condensing wall hungs on this thread."

OP stated:
"...Also, I need to learn more about all of this. Any ideas for websites dedicated to details about hydronic heating function and set-up?..."

Apparently it is only you and not the OP who wants to limit the discussion.

EricAune

hear, hear!

Steve Ebels_3

Steve is........

Throwing a bag of popcorn in the microwave and going to sit back and watch the fight...................I mean discussion.