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Old 01-15-16, 10:51 AM   #12
Uber EcoRenovator
Join Date: Apr 2011
Location: Strathroy Ontario Canada
Posts: 654
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Yes I understand the Propylene Glycol has a life expectancy. I had the understanding its about 6 yrs. and it turns a brown color and smells burnt. I do check it from time to time by taking a sample and putting it in the deep freeze. I need protection down to -22 Deg C.
I have found that even if the temp is lower it just turns to slush and there is no chance of expansion causing a burst pipe.
Mikesolar had mentioned to me sometimes it can be hard on O-rings (rubber) causing a sticky valve. Well I think he was right. Don't tell him, it will go to his head.

My Propylene Glycol still has a protection down to the -22 Deg. C. its colour has changed from its light blue to a green colour probably from the copper. Working on the copper pipes a cutting has a light dust coating on the inside. This could be my hard water that I had originally used to make up the solution.

Overall we are very pleased with the solar hot water system. Its saving us a pile of money.

randen is offline   Reply With Quote