To begin winterizing my water system on my old "93" Komfort fifth wheel I need to start by shutting off the water to the hot water heater/tank. I do this by looking under the cabinet where my tank is located for a shutoff valve. The blue handle in the photo at left shows my valve in the off position. By turning this valve off I will be able to drain the tank without letting my pump or city water continue to try to fill the tank as it drains and I won't try to fill the tank with antifreeze. That would require six gallons and is unnecessary.
Next I'll go outside and open the door to my water heater and using a 9/16" socket I will remove the drain plug. Because I have the valve closed on the inside of the tank I need to allow air into the tank to let it drain properly. I do this by simply opening the safety pressure valve at top of the tank.
I have removed the drain plug and water is now draining. Normally more water would be coming out but I took this photo as it was nearly empty.
The next process is to either blow all the remaining water out of the lines using an air compressor with a large enough reservoir to force the water out or as in my case, I am adding an RV antifreeze. You never want to use the kind of antifreeze you put into the radiator of you car as that is a deadly poison. RV antifreeze is specifically designed for RV water systems and is perfectly safe. I recommend using RV antifreeze in any system where you think blowing the water out may not totally clear the lines. Because the place where I leave my trailer in winter gets so very cold, I don't want to take any chances so I add RV antifreeze. The process is very simple. There are kits you can buy to place in your water system that make this easy but my water pump is under the couch and is very easy to get to.
To add antifreeze to my lines I simply drain my freshwater tank and pump all the water that the pump can pull from the tank in to my holding tanks. Then I remove the hose from the pump on the inlet side. Next I connect a short hose to my pump and place the other end in a gallon jug of RV antifreeze. Once this is secure and I'm sure the jug won't accidentally tip over I turn on the pump and open each faucet. I usually start with the one farthest from the pump. You need to turn on both the hot and cold water at each sink and tub and shower.
Turn the faucets off as soon as you see pink antifreeze coming from the faucet. Keep in mind that you also need antifreeze in each "P" trap under the sinks. I simply leave one of the faucets open long enough to ensure the water in the trap is replaced by antifreeze.
Be sure to flush the toilet and turn on the shower and tub as well. Don't forget the outside shower either. I found that my system needs just a little over one gallon of antifreeze to fill all the lines.
I pour the remaining antifreeze into my fresh water tank. This makes sure any water remaining in the tank will not freeze and it allows me to pump antifreeze into the line between the tank and the pump. It also allows me to come back later if I find I forgot something. In my case I forgot the outside shower until I posted this blog so I'll go back and do that later today.
The picture shows my simple funnel for adding antifreeze, Clorox or even water to my fresh water system. I just cut the side and bottom off a plastic Clorox bottle. The pour spout fits perfectly into the filler spout of my system.
Next Spring when I "de-pickle" my RV for use, I'll use this to add clorox to my tanks and lines to kill any fungus that might be in the system. I noticed that the filter at the pump was a little dark looking so I suspect I will need to clean the entire system again.
I recommend that before you begin adding antifreeze to your fresh water lines, you should empty all your holding tanks. Make sure they are as clean as you can get them. Then as you add antifreeze to your fresh water lines, you will also be adding it to your holding tanks. It's not likely that you will have a holding tank break from freezing if it is empty but this will add a little more insurance to that policy. A few extra dollars spent on antifreeze can save you a lot of work if you do your own repairs, or a lot of money if you pay somebody else to do repairs for you.