Low Point Drains

You should have a fresh water tank drain somewhere under the rig. Look for a small pipe hanging down with either a valve on it or a cap on the end of it.

And simply opening the low point drains is not likely to drain all the water from all your water lines.

How do you know the tank is not empty?
Low point drains drain the water lines not the tank.
If you have a few gallons left in the tank nothing is going to happen. Water freezes, it expands. There is plenty of room for expansion in the tank.

donn0128 wrote:
If you have a few gallons left in the tank nothing is going to happen. Water freezes, it expands. There is plenty of room for expansion in the tank.

That would depend heavily on the design of the tank. If it is a fully flat surface, you are probably right. Some tanks, however, have smaller bowl-like areas at the drain location in order to help funnel water to that point. In those cases, if water fills that bowl, expansion could cause a crack even if there is plenty of room elsewhere in the tank. A few drops that remain are one thing, but I'd never leave gallons thinking it wouldn't cause a problem.

We don't have a class A, but as others have said, our trailers always had a small spout that could be used to drain the tank. I open it up and drive home from our final drip with it open, that way I am confident that most everything has drained.

TWZMYJP wrote:
....How am I supposed to get all of the water out for winterization and freeze protection? Unfortunately the water pump suction port is too high, and leaves at least 2" of water in the tank as well so that's not an option either...

Drain as much as you can by opening the tank drain and the low point drains, then put in the "pink stuff" and run the water inside at all faucets/showers/toilets until it gets in all the lines. Before storing for the winter, I usually drain everything I can, put in about 10 gallons of RV antifreeze into the fresh tank, turn the pump on and run everything until it runs pink. I then put about a gallon each into the black and grey tanks for good measure. At the end of winter, I drain the fresh tank, flush it with fresh water and run everything until it runs clear and then sanitize the system with bleach. Then...flush everything again......

I have had to use the more serious method before to locate the tank drain. I got under the rig with a flashlight in the vicinity of where the water fills and searched for a hose hanging underneath.

In one case, it was recessed into the bottom of the unit and had a plastic valve in the recess that I opened to drain the tank out.

They are often located near where your water pump is, so look around there.

I like to drain, then leave it open as I drive around for awhile, uphills and down and around corners. Quite a bit more can often come out.

I have also had to repair a rig that had a cracked tank drain outlet valve because someone left too much in the tank before me.

Thanks for all of the input gang. Unfortunately, I've been all over this darn thing and I can't find any other valves or lines that I haven't already traced and identified, and none of them are what I'd consider a tank drain... This is our 4th RV so I'm pretty familiar with how things are supposed to work, and my typical draining and winterization plan is a mixed bag of a lot your comments and recommendations, so thanks again for all the input. I'm fearful that this may be an oversite by the factory...

TWZMYJP wrote:
I'm fearful that this may be an oversite by the factory...

Is this a new unit that you bought from a dealer? If so, I'd contact them to find out where the FW drain is in that unit. If they don't know, have them contact the manufacturer to find out. If it's an oversite, and you recently purchased it new, they should fix the issue for you.

I know some have suggested putting antifreeze in there (which I would not want to do anyway). In your case, however, it's especially problematic, as you'd never be able to get it fully drained and clean because you can't fully empty your tank. I'd hate to have residual antifreeze in there all season long.


If at all possible, I'd get to the dealer and try to locate the solution.

Have you called Jayco/dealer? Another method is, open grey tank, turn on pump and ope a faucet. When the punp pulls no more water, there is very little left in he tank. I would still want to find the tank drain, though.

A friend told me years ago, ice cube trays don't break, your tank is just a big ice cube tray. I will never put antifreeze in my fresh water tank.
This new AF has a 2" (or very close) dump valve for the fresh tank.
I drain everything, pump in the pink stuff, then drain that out. It sure makes it a lot faster when I want to use it for a weekend in the winter.

Mickeyfan0805 wrote:

That would depend heavily on the design of the tank. If it is a fully flat surface, you are probably right. Some tanks, however, have smaller bowl-like areas at the drain location in order to help funnel water to that point. In those cases, if water fills that bowl, expansion could cause a crack even if there is plenty of room elsewhere in the tank.

As long as there is room in any direction, the situation you describe would not result in a crack. The water will expand up if/when it freezes, just like in a plastic ice cube tray.