The only filter we have is the house filter in a cannister by the water hose hookup....we have a small line that runs to the icemaker of the residential fridge....it comes from a line under the bench in the bedroom, out of the cold line feeding the hot water heater....no filter there....my concern is getting the water out of the icemaker line for winterizing...as near as I can tell, there is no easy way to do that, or even know that it is done....