When our South Dakota Chapter Guide, Lesa McDermott, experienced -7 temperatures the other day, she reached out to our expert, Mark Polk, when she realized her RV antifreeze was slushing. Here is the quick RV antifreeze education Mark provided for us.
RV/Marine antifreeze protects against what is referred to as “burst protection” not necessarily against freezing, and this is important.
The damage to a plumbing system when it freezes is caused by the ice in the plumbing line or fitting freezing, expanding and then rupturing. The rupturing part is what you don’t want to happen.
The Burst Point
RV antifreeze rated for -50 F and -75 F will start to freeze at around 20 F, but it won’t freeze to the burst point until -50 F or -75 F respectively.
In parts of the country where temperatures go into minus digits and stay there you should use the -100 F antifreeze for added protection. This type freezes at about -20 F, but provides burst protection to -100 F.
Drain those Water Lines!
Something else important to understand is you need to evacuate as much water from the plumbing system prior to adding the antifreeze, because diluted water and antifreeze will freeze and burst sooner than the rated temperatures on the bottle.
Mark Polk, RV Education 101