If you’re an RVer that travels in the winter months, stores your rig in the winter or both, there’s something about winter that will give you fits. That’s the plumbing system. Water expands as it freezes.
As water expand, it puts pressure on plumbing system and eventually breaks through the weakest link (copper pipes). Now what started out as a little inconvenience becomes a major repair bill with a busted line. Yeah, yeah, I know, you think draining the tanks is all you need.
Nope. Wrong answer. Pex tubing holds a lot of water on the low spots and can cause some pretty bad damage.
The fresh water tank hold water. The toilet flange hold water. The heater core, the water pump, etc. Hold water.
It’s just little bits at a time but they’re enough to break a pipe once temperature drops below thirty two degrees. You’ve got to get it all out. And you’ve got to have something that pushes it all out.
How to Winterize RV Plumbing With Air
Why RV Plumbing Freezes in Winter
The best way to make sure you know that your plumbing is dry is with compressed air. If you’ve never witnessed this, it can sound terrifying. Hoses is attached at different locations throughout your vehicle, and you can rent an air compressor.
But no, we’re not violently blowing stuff apart here, we’re trying to coax the water from the system as gently as possible. What you’re looking for is a slow but continuous stream of air that pushes the water out without tearing apart fittings or blowing out seal washers. The right amount of pressure are the difference between successful winterizing and blowing out a washer.
Using Compressed Air for Winterizing
A good air compressor. The volume of an air compressor matters. I don’t think you’ll get away with a small two-gallon pancake compressor.
To pump air down long lengths of tubing you want steady flow. For a one time use it’s probably best to rent something bigger from Lowe’s or Home Depot. Something that puts out roughly forty to fifty PSI.
That way, even if there is some distance between the spigot and the faucet, you won’t blow up your plumbing. It also shouldn’t be too weak to push water. Be sure to bring along your own air hose so it matches both your RV service connection as well as outlet on the compressor.
Selecting the Right Air Pressure
Next close all your faucets before turning on the air. There are no negotiations here. If there’s an open faucet somewhere, the air will just escape through it.
It won’t pressurize enough to send water everywhere else in the system. Turn off both the hot and cold side of each sink. Turn off the shower valves.
Turn off the toilet fill valve. Some RVs has a main shut off valve for the water heater. Turn that off too.
What you’re trying to do is force the air to go around the whole system before it exits. You’re creating a closed loop.
Blowing Out Fresh Water Lines
First, blow out your fresh water lines.
Hook up your air hose either to city water connection or to your water pump’s winterizing port. Verify that any bypass kit you have installed has been positioned correctly. Switch on your compressor and set it between 40-50 PSI.
Open the faucets one at a time beginning with the farthest away from where the air hose was connected. Pay attention to the sound. Listen for the change in sound.
Air coming out sounds different than water; it is a dry, rushing noise. You’ll know when it changes because it will be rushing around making very dry sound. Let air through until you are confident that nothing but air is exiting.
Do this for each faucet in the rig.
Clearing Holding Tanks and Water Heater
Do not blow out the black and grey water tanks with high pressure too quickly. That will not only ruin the seals but also possibly harm the walls of the tank.
How do you get rid of what’s in there then? Use air to help gravity do its job. Run some air through the system while the faucets for fresh water is opened.
What happens is all of the water left in the holding tanks gets pushed by air into sewer hose. Have your sewer hose hooked up and running into a dump station. The air pressure also assists with getting rid of those stubborn puddles of water that always seem to be stuck down there in the bottom of the tanks.
Slow process but it works.
Don’t neglect the water heater (this is where it all goes down). Most catastrophically.
Remove the anode rod if you have one and turn your pilot light off (if it’s a gas heater). Now, take some air and blow it into the tank from the drain plug opening until it’s completly dry on the bottom. With an electric only heater, you can skip the air step by draining it, but it’s better to blow it out because any residual water in the housing of the heater elements can lead to corrosion and even shorts over the winter months.
But it’s better to blow it out. Any leftover water in the heater element housing can lead to corrosian or even shorts over the winter months. A little preventive maintenance can save you a big headache.
Protecting Traps with Antifreeze
Lastly, Fill up the sink and toilet traps with RV Antifreeze. There’s just a small amount of liquid left in the P traps after the air clears out the lines. This will freeze and crack the plastic or porcelain if you don’t fill it with something.
Add a cup of non toxic antifreeze to each drain using a pump. It stops freezing by sitting in the trap. It also keeps sewer gases from creeping back into your livig space.
Now your RV is good to go in the cold. The air did most of the work. Park confidently now knowing your plumbing is protected from the freeze.
Actually, you should of checked everything twice. It would of been better if you did that earlier. Making sure things are moddern and ready for wintery weather is important too.
Everything looks luxurius when it works right. You’ll recieve a lot more enjoyment if you don’t dissapear into a repair shop.
