Floor Heat Anti-Freeze pH

[GoBuckeyes]

Has anyone had a problem with their FH anti-freeze turning acidic? At one of our washes, the antifreeze pH is testing 5.2 and is being blamed for our leaking expansion tank. Every weld on this tank, which is only 15 months old, is failing! Our city water pH tests neutral at 7 (today anyway). I still have some undiluted Ethylene Glycol and it's pH is 8. So how does a 50/50 mixture of soft city water and ethylene glycol get to a pH of 5.2 in a span of 5 years?

I tested the anti-freeze mixture at another wash and it was a pH of 5.8. That anti-feeze mixture has been running for well over 20 years and that expansion tank from the same manufacturer isn't turning into swiss cheese like my new one? Any ideas? I understand a pH of 5 is 10 times more acidic than a pH of 6, which is 10 times stronger than 7 etc. but how acidic is 5.2 in everyday terms?

 

[2Biz]

Heres a great article that answers a lot of your questions:

http://www.solarbair.com/articles/glycolarticle.html

Something maybe not listed in the article, Expansion Tanks are not all the same. The one I just bought for my Boiler Install is designed to be used for glycol based systems. Something to maybe check out...

http://www.pexuniverse.com/store/category/radiant-extrol-expansion-tanks

One of the things I adhered to when filling my system, I used Distilled water to keep from getting any disolved solids in the system. Lastly I installed an air seperator to keep oxygen out. Any of these things listed, if not installed properly, will allow your glycol to become acidic faster.

You can always try to add some "Inhibitor Boost" to raise the PH. It is recommeded checking the PH yearly and if it drops a little, its much easier to bring the PH up with Inhibitor Boost than if it drops too low.

I noticed you used Ethylene glycol. I used Propylene glycol. One is safer to use than the other, (Ethylene is poisonous)....My old system had Ethylene and was in there for over 25 years...Plus it was basically an open system. Go figure...