Cannot drain my fresh water tank

[Hingafer]

Hi,

This is my first time ever joining a forum so I'm a forum newbie and also Airstream newbie so Please forgive me for any mistakes. The reason I'm joining is because I cannot find an answer anywhere else. I have a 2006 Airstrream International signature 23'. I had drain my fresh water tank many times before for sanitizing purposes. before I drain, I open up all the faucets then go outside to open the fresh water tank drain located behind the two wheels on the utilities connection side. The water from the tank would gush out right away and would only take few minutes to empty the entire tank.

Last week I was trying to do the same, bleached the fresh water tank and filled my lines with beached water. A day later I tried to drain the tank. Opened all the faucets then open the fresh water drain valve but nothing happened.

I couldn't figure out the problem. I turned on the pump then suddenly the drain started to flow but the faucets didn't produce any water. Turned off the pump then the drain stops simultaneously. All the while there was no water coming from the faucets. I find very strange. Maybe I missed a silly step somewhere.

I am a little lost so any advice will be greatly appreciated.

[Hingafer]

Sorry, its a 2010 Airstream International Signature

[Larry C]

You probably won't get any water out of the faucets when the low point drains are open, and the pump is running.
Why don't you find the drain valve for the fresh water tank, open it, and drain it that way. There must be one somewhere. The valve you are looking for is a white plastic valve and it should be located at the outboard end of the fresh water tank.
Open it 1/2 turn from the way you first see it, and it should drain..

Good luck,
Larry

[HiJoeSilver]

Yep strange.
Opening the faucets doesn't make a difference, they're on the outlet side of the pump and there's a check valve so water and air aren't going to flow back from them into the fw tank. Unless you were flushing the bleached water through them with the pump while draining the tank.
Strange that drain flows when pump runs, stops when not. One thing I can think of would be a kinked vent line , pump may be able to break the suction lock on the tank enough to get air flowing into the tank through the vent while gravity alone may not.

[Al and Missy]

I mistook one of the low point drains for the tank drain. The symptoms were the same as you reported. Make sure you are opening the tank drain. Mine is on the curb side of the fresh water tank pan behind the right front wheel. A low point drain is nearby in the bottom of the tank pan between the curbside wheels.

Al

[cwf]

Picture time... Take and post picture of your "valve" for emptying the tank.

[mefly2]

Listen to Al ...

[dbj216]

I get to chime in too! One remote possibility is the fresh water tank is not vented when you are trying to drain it.

Your fill port likely has a vent tube to it, with a plastic plug in it. You probably already have, but make sure the plug is out, or the fresh water fill cap is open.

Maybe it drain when the pump is running as the pump is breaking the vacuum in the tank.

The cheap plastic drain valves that Airstream used for years are problematic. And dirt in the tank can plug the valve. Or like mine, they seize up and the plastic handle breaks. At least mine broke in the closed position.

I often drain my fresh water tank with the 12v pump, into the gray tank, and then into the sewer.

David

[Hingafer]

Thank you so much for everyone's suggestions. I will investigate more based on your suggestions in tomorrow. Every fall I had the RV dealer in Calgary, AB do my winterization but last fall I did it myself. I will check to see if there is anything that I had missed when reconnecting the suction line to the pump. The strange thing is that I had drained my fresh water tank so many times, for dry camping I would drain the tank before heading home. I wasn't aware of any vents in this system, thought opening the faucets was a way of venting which is what I normally do. I really would like to avoid having to use my pump to pump the entire fresh water tank to the grey water tank then drive to a dump station. Seems too much work.

Attached are two photos I took this morning. On my Trailer the drain is not on the curb side (unless you are in Britain).

[The Ice Man]

Nope, that appears to be a low point drain. The tank drain is the little white spigot above the center point of your arrow. At least it is on mine. It's accessible between the tires.

[Al and Missy]

What the Ice man says. See my post above. The grey plastic valve behind the tire is the tank drain. I guess AS moved it between my 2001 and your 2010 or that is a difference between the 23 and 25.

Be prepared for it to be REALLY hard to turn. Mine was so stuck that I was afraid I was going to break it. Multiple applications of food-grade silicone spray loosened it up. If your trailer has been winterized regularly by using the drain valve, maybe it won't be hard.

Al

[Hingafer]

Thanks Ice Man and Al and Missy and everyone else. I will try this plastic valve tonight. Hopefully it will open without breaking off. I will post the results tomorrow. Thanks again! really appreciate the help.

[AWCHIEF]

If it is difficult to turn you can use needle nosed pliers. I mad a DIY tool for the job.

[biyak269]

Mine did that. I connected an air compressor hose to it for a second (with the fill cap off, thank you). It worked fine afterward. I assume that a spider or something else lodged in in the drain valve, blocking it.

[rmkrum]

Typically mud dauber wasps or the like...


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[AWCHIEF]

I think the OP has it figured out. He has been opening the wrong drain valve.

[Hingafer]

Well last night I opened the white spigot valve (w/o problems) and water started to drain out but very slowly. Previously I had opened the low point drain and water would shoot out as if under pressure (maybe just discharge head). Thanks again everyone.

[dbj216]

Mine drains slowly also. Like several hours. It is a small diameter valve. Your low point drain valve may have had some water pressure behind it from the water heater or accumulator somewhere.

David

[Philipp]

I have exactly the same problem. My drain valve opens but the fresh water just drips out. Used to work perfectly. Any advice what to do without having to replace the full valve?

[Adventure.AS]

Originally Posted by Philipp

I have exactly the same problem. My drain valve opens but the fresh water just drips out. Used to work perfectly. Any advice what to do without having to replace the full valve?

Open the taps inside and the filler cap outside to let air into the system.