Unfortunately, it is that time of year again (at least for me). Time to get the unit ready for winter.
Since there are a ton of new Axis/Vegas owners on here since the last thread of this type I figured I'd start a new one. (Most of this is specific to my 24.1 but will probably apply to the other Axis/Vegas floorplans and other RVs as well).
To start out with you'll want to relieve pressure off your water system and remove the water heater's drain plug (on mine its a plastic plug near the bottom left of the unit--a pain to unscrew because its behind a pipe). If you want the water to drain faster you can open the safety valve at top (I usually just remove the plug and leave it out until spring--so far no critters have decided to take up residence in the water heater for the 16 years I've been doing this).
Next you'll want to remove the panel under the passenger side rear bed--on ours its two square head screws and it comes out. Optionally you can remove the cold-air return grate as its easier to get to the water heater bypass valves from there.
After that I open the drain valve for the water tank and close the feed valve (so the water pump doesn't draw water from the tank). These valves are right next to each other right where the waterlines leave the tank. You can tell the feed valve because its hooked to the pipe going to the water pump, and the drain valve because its the one with the right-angle fitting that goes through the floor.
I'm going to steal FW28z's excellent diagram here: (You'll want to configure the valves for the winterized position)
Here you can see my water heater valves on "winterize"--at least the bypass and hot water ones, the cold water valve is below the grey furnace vent pipe.
Next you want to hook up some hose to the "antifreeze injection point": There is a tube sticking up that is capped. Get a fitting to screw in there and some hose--I use clear vinyl so I can see the antifreeze go through it:
It usually only takes about 1.5 gallons of pink stuff to winterize my Axis--I get extra just in case.
Now turn the pump on with the kitchen faucet open slightly (using kitchen because its right next to the pump switch). The idea here is to have a faucet open so the pump can suck up the antifreeze--try it with all the faucets closed you won't get very far LOL.
Once you see the clear line filled and hear the pump slow down because it has some antifreeze in it close the faucet. Now you're ready...
Go around the coach opening up one side (cold) and then the other (hot) until you see pink stuff coming out. Make sure you do every faucet including the outside shower, the shower head, and the toilet. It should be really pink coming out:
You'll probably empty the first gallon during this process. When you hear the pump running with no antifreeze coming out just turn off the pump, replace the bottle with a full one, and repeat the priming like you did with the first bottle.
When all the sinks are done I also go and briefly open up both low point drains (right next to the water tank) and the two water heater bypass valves so that they all get antifreeze going through them.
Lastly I leave the system semi-pressurized (not fully), take the strainer out of the city water hookup, and lightly press on the check valve there to get some antifreeze to come out there. Don't do this with a fully pressurized system because you could damage the check valve. (There was some discussion about me doing this in another thread--some people recommended not to if I'm remembering correctly.)
When I'm all done I pour any remaining antifreeze into each sink, the shower, and the toilet to make sure that there is antifreeze in the traps and the waste tanks (even though there probably is from the winterizing process but, in this case, more is better). In addition this allows me to use up all the antifreeze and recycle the bottles (no real reason to have a 1/2 full bottle of RV antifreeze sitting around).