frozen pipe in hot water system

[karly64]

When my hot water system shuts down between heating cycles one of the pipes freezes in very cold weather. I want to add ANTIFREEZE to the system to prevent freezing and the possibility of a burst pipe as the pipe is inaccesible under the house with no way to get under house to insulate the pipe. My question is what percentage antifreeze to water should i use and is RRV antifreeze ok to use? THANKS KARL!

[Bob53]

Greetings, I purchased glycol for this job at our local heating & plumbing supply outlet. Cost ran about $40. for a 5gl bucket and my 6 room house used 2 buckets on our FHW system. You will need an electric pump and a small garden hose with a female fitting on each end. A washing machine fill hose works perfectly to push it into your system as it pushes the present water out. I made sure to prime the pump with the glycol. When the glycol started coming out that's when I knew it was thru the system .That's the way I put it in anyway. I found it to be a pretty strait forward DIY project. I am not sure about use of RV winterinzing fluid. I think the price was worth it. Hope this helped.
-Bob

[KField]

A 30% mixture is best. If you use too much, it can foam and make noises when it passes through the boiler. You can buy an inexpensive tester for propylene glycol mixtures. It is less than $10 and all you need is an ounce or 2 of boiler water to test. I would use boiler anti freeze like Bob suggested.

Ken