Glycol question for TAB320CSS

kdawg

We have some glycol in the system and some left in a bottle. It's Century Heat Transfer Fluid gallon in the yellow bottle. The instructions say "do not dilute." However, I'm searching now for the same brand and type, and the only ones I can find are the versions that you should dilute. Is it okay to mix these? They are the same brand and seemingly the same exact stuff, just with different potency. 

kdawg

Nevermind! was able to speak to someone at the company. Okay to use the same company brand even if one is diluted and the other is not. 

pthomas745

The Century comes in two flavors: diluted with propylene glycol and "water", (I'm assuming distilled.) And, undiluted glycol that needs to be diluted before using it in the Alde.

The Alde FAQ says this about the glycol "mix", if you want to use "undiluted" glycol.

"The heating system must be filled with a mixture of water and glycol. Use only high quality ready-mixed glycol (with inhibitor) intended for aluminum heating systems. The heat transfer medium must be Propylene glycol based boiler antifreeze. The antifreeze must meet FDA (GRAS) standards or be non-toxic fluid having a toxicity rating or class of 1, as listed in Clinical Toxicology of Commercial Products, 5th ed.

If you are using concentrated glycol, the mixture should consist of 60% distilled water and 40% glycol. If the heating system will be exposed to temperatures below -15 °F (-25 °C), the glycol content must be increased but not to more than 50%."

Note the mixed signals from Alde here again.  "Use only...ready mixed glycol" in the first paragraph.

And in the second paragraph "If you are using Concentrated glycol the mix should be....etc".  They are really terrible at manuals and FAQs! The Alde manuals use the same contradicting instructions.  

The "Super  Concentrated" Century is available at Amazon with the instructions right on the label about how to dilute it.