I'd be worried about a lot of things besides my water filter. Are you sure the dealer didn't winterize it? if they did not, you need to totally winterize it by draining ALL water from all the tanks, lines and water heater. Pump a small amount of antifreeze into the water heater, then open the bi-pass valves and pour 2-3 gal of antifreeze into the fresh water tank and run each water spicket ( both the hot & cold) until pink comes out. Don't forget the toilet and put a cup or 2 down each drain to fill the trap. If there's any question as to how to do this process---get it in the dealers heated shop NOW. If it freezes up, you'll have broken pipes and potential leaks throughout the unit!!!!!!!!!