The water filtration system used by Forest River, at least the one used on mine (2014 HW277) the WaterPur Company model # CCI-5CLW12 also cracked. I don't think your issue was due to freezing temperature or winterizing, these filter flat out suck (shame on Forest River)
I live in South Florida, and as you would expect, our weather is not cold down here and mine cracked just like yours did.
Since then, I have just bypassed the filter system with a flexible braided shark bite pipe and use an outside filter. In the event the new filter was to crack/leak, I won't have to worry about it much.....
Will forward a few pictures when I can.
Hope this helps someone out there.
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