I thought that Heartland had the antifreeze pick-up tube and valve on all the models. No Problem. You can go to any reputable RV parts shop and pick up the kit or shop on-line or go to camping world. All it entails is a valve that you install in line with the hose coming from the freshwater tank. It usually threads right on to the pump and then the hose from the tank screws on to the other side of the valve. You place the pick-up tube into your container of antifreeze, turn the valve to pickup the antifreeze and when you turn on your pump, it pulls the antifreeze through the pump and into your supply line going to all your sinks, shower, toilet.
BE SURE TO BYPASS THE HOT WATER HEATER. You do not want it in there. I then go to each faucet and turn it on till the pink antifreeze arrives, then turn it off. Do both cold and hot sides. I pour a little into each p-trap. Don't forget the outside shower if you have one, and also the shower and the toilet. I don't pour any into toilet and let it sit on top of the flap...the pink stuff can stain it if it's plastic. I usually use 1 gallon on our 2010 2900MK Sundance, but I've always got an extra jug. I always open up the low point drains and empty the lines first, then close them and do the winterizing.
I think I got the steps right. We have one last weekend of camping at Lake Tahoe, NV this week then I'll winterize and put baby to sleep for the winter.