Canisters are like external pipes in the home in that, if they freeze with water in them, they will burst, causing a BIG mess! If you purchased a one-, two- or three-canister system from RV Water Filter Store in the past, we will have a replacement for you. If you didn't get them from us, we won't be able to help as each canister manufacturer has unique heads, sumps and o-rings.
Over the history of RV Water Filter Store, we have had three different brands of standard sized canisters as our primary offering. First was Pentair, then Kemflo, and now Hydronix. If you purchased your system after 2016, You probably have Hydronix canisters (our current brand) but they may also be Kemflo, since we were converting canisters during that time. If you can compare the pictures below to what you have, you see that the big difference is that Hydronix flares out at the top, and the Kemflo goes up evenly. If neither of those look right, the Pentair canister was the first one we used. These have opposite threads vs the other two, with the male threads on the sump and female on the head.
Here are the links to the replacement sumps
Pentair Canister Kemflo White Hydronix White Hydronix Clear