Let me tell you, if you are one of the RV owners that think all you need to do is just use a blow-out plug on your RVs water system you are sorely mistaken. First of all your RVs water system is only rated for 55-65psi MAX!!! Have you looked at the gauge on your air compressor lately? Is it set to 55psi? No... It is more likely set to around 100 to 150 psi, THAT IS WAY TOO MUCH. Yes blowing out the lines might work but what you are forgetting is that inside a tube when you have water in it and blow air through the tube all your going to do is spread out the water. Just as soon as you remove the air pressure the water will run back down to the lowest point in the line. Take for example, put some liquid in a bendable straw, bend the straw into a 90 degree angle straight up toward the ceiling, now blow. What happened? You cleared some of the liquid out of the straw but not all, right? Well that's what happens with your RV you can get some or maybe even most but you will not get all. Now when the water freezes it happens very slowly so all the water in the elbow pipe fitting gets solid and then once it gets solid along its journey to ice it expands and in turn breaks the fitting. Now just so you know the fittings are more likely to break than the pipe depending on what you have in your RV. (Did You Know? If your plumbing tube is GRAY you have the old polybutylene the not good stuff there has been recalls on this, if your tube is Opaque, Blue, or Red you have pex that is the good stuff.) Now that you have proven to your self that blowing the lines won't get all the water out, your forgetting an important part of the system, you can open all the faucets hot and cold sides but its hard to blow out the toilet valve because your outside putting the air on the blow-out plug you can't hold the toilet valve open. Now I know some of you are going to say I will beat the system and have someone hold the toilet valve open for me while I put the air on it. Well smart thinking you just fixed the problem and prevented your self from freezing, there is no reason for you to continue to read this article you have it all figured out. Now for the rest of you that want to prevent the problem of freeze up. It is very simple. WINTERIZE the entire system including the toilet. Now it's easier than you may think. When I was in the business I built a winterizing system. You can do the same, I will give instructions later on how to build. Some RVs have a kit on the unit that will use the pump to do the work for you.
TO WINTERIZE:
1) First thing! THROW AWAY THAT BLOW-OUT PLUG! You don't need it.
2) Drain the on board waste holding tanks and flush with allot of clean water so you can leave the valves open when your done. (Dump the waste tanks in an approved waste dump station) The reason for leaving them open is because the air flowing around an open valve will dry any left over moisture so if you need to close the valves during the winter you can. If you close them they might freeze and you won't be able to open them easily.
3) Drain the on board fresh water tank and leave open this is a good time to put some bleach in your tank just to clean it and help prevent mold. Put the bleach in before you dump the waste tanks so the bleach water can be used to clean the waste tanks during the flushing process.
4)Drain the water heater. Do this by opening the water heater access door on the outside of your camper and removing the plug at the bottom of the heater. Do not reinstall, leave this plug out. I just leave it laying in the bottom of the water heater compartment and close the door back, before you close this up, open the pressure relief valve to help the water heater tank drain. Pressure relief valve is shown below in the yellow square.
5) Set your water heater by-pass valve kit to winterize. This way you do not fill up your 6-10 gal
water heater tank with $5.00 gal antifreeze. If you don't have a water heater by-pass kit you can install one
fairly easily.
Now I will tell you how to fix your RV to have your own on board winterizing kit. First find your water pump. Now you will find the input side of the system, the tube coming from the fresh water tank going into the pump. Cut that line about 6 to 18 inches back from the pump. Now install a (I like SeaTech) 3 way valve in line where you cut the tube going in the pump. Now insert the stackable hose barb into the single side of the 3 way valve. After that get a piece of 1/2" flex clear vinyl tubing about 18 - 24" long and one Stainless Steel hose clamp from the hardware store or home center. Install the vinyl tubing on the barb and put the clamp inplace to hold the tube on the barb. Now all you have to do is turn the valve and insert the clear vinyl tube into the bottle of antifreeze and turn on the pump. Most RV water pumps are what we call on demand, which means they will run when the pressure is released when the pressure builds up they will shut off. Now all of your faucets should be still be turned off at this point.
Another tip. Get a small removable boat gas tank such as the Moeller Product # 003780, this is a 3.2 Gal tank you can put your antifreeze in and hook up your flex line to the tank. (Now be sure you DO NOT USE THIS TANK FOR GAS AT ANY TIME!!! This is the water system for your Home away from home. You don't want to drink gas do you? Mark this tank well you can also use spray paint and paint the tank a different color, the Krylon Fusion works on plastic.)
Most RV systems will only use 2.5 gals of antifreeze. So if you buy 4 gals you will be safe, fill up your winterizing tank and keep one for a spare.
6) Now go to the farthest faucet and start with only the cold side, lets say in the shower. Only open the cold water valve, Do NOT open the hot side. With the cold valve open watch for pink color to be solid pink, don't let it run for too long but long enough to be solid pink. (The reason for only opening the cold side is so you really know that your getting both the hot and cold lines full of antifreeze. If you open both at the same time you will not know for sure that they are correct.)
7) After you turn on all of your cold valves, (Don't forget the toilet and outside shower) then go in the same order and turn on the hot side and do the same as you did with the cold. After that is done turn off the water pump. I like to pull the water pump fuse so even if you turn on the switch the pump will not run.
You have CORRECTLY winterized your RV. Now you shouldn't have to worry about freezing.
