Although there is a valve on the rear of our refridgerator that can be closed to prevent antifreeze from entering the refridgerator during winterizing, I prefer not to use it as I feel that blowing out those lines is not sufficient protection. I do pump antifreeze into the fridge which then does require purging it out in the spring.
As mentioned, simply flushing it through the water dispenser is the easiest way. I would suggest doing the flushing without the water dispenser filter in place as the flow rate through the water dispenser will be about 3 times as fast. I usually hold a 1/2 gallon container under the dispenser and fill then empty it about a half dozen times to completly flush the system. With the water filter removed and the rig connected to a good water supply each time I fill the 1/2 gallon container only takes 15 seconds or so, so the flushing goes pretty quickly.
Once the water is flushed clear, allow the icemaker to make several batches of ice and discard them. The first batch or two will be a little pink.
The antifreeze in the icemaker will freeze enough for the pink cubes to be semi-solid and eject from the icemaker. Rv antifreeze actually does freeze into a semi-solid state, but does not expand when it freezes like plain water does. It's the expansion of water when it turns into ice that damages water lines and fittings.
Joe & Shelly, Justin, Tyler, Alyssa | Butler PA
2008 Tiffin Allegro Bus 43QRP|Cummins 425|Honda CRV