Saturday, January 29, 2022


Too chilly for antifreeze?

By Chris Dougherty
Chris Dougherty is a certified RV technician. Here is a letter he received from a reader while he was serving as’s technical editor.

Dear Chris,
chillyI keep two gallons of RV antifreeze on hand in case needed. The last few weeks I have watched it carefully. At 9° F it is mostly slush and almost not flowing at all. At -20° F it does not flow at all and is nearly as hard as water. I have two campers winterized, I thought, with this. I hope I still have plumbing out there. Anyone else who observed this? Think all will turn out OK? I would like opinions on best brand for future reference. —Dan

Dear Dan,
Antifreeze has two ratings: a freeze point and a burst point. This is because when a liquid freezes it solidifies and expands. “Propylene glycol antifreezes are designed to provide burst protection to temperatures of -50˚F. or below,” according to Camco. “Ice crystals will start to form in -50 RV Antifreeze at temperatures around +10˚F. and will appear to be solid ice at around -10˚F. to -15˚F. Propylene glycol based antifreezes continue to contract and will not expand until temperatures of -50˚F. are reached, thus providing burst protection for pipes.”

So, I think you are just fine! I’m sure you’re looking forward to spring as much as I am!



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