No Water Out Of My Fresh Water Low Point Drain Valve

[sonuvabug]

I just winterized my truck camper. When I went to drain my fresh water tank, nothing came out. I ended up using the on board water pump to drain it. I'm thinking the drain line is somehow blocked? ... or the valve is not functioning as it should?

The drain valve plumbing comes out of the fresh water tank in the basement at the back of my truck camper and it is only about 1 foot long. You can visually inspect the entire drain line and there is no obvious problem. I was thinking about "snaking" the drain somehow but have never done this. What suggestions do you have?

[joeshmoe]

Don't snake it. You're gonna damage something. You can't negotiate the turns with fittings that small anyway. Just give it a shot of air. Maybe 20-30 psi. However...

From what you describe, I honestly don't think there's a problem. If it drains when you turn on the pump, there probably isn't a blockage.

Mine won't drain either unless I turn the pump on.

[SidecarFlip]

Had the same issue. Use a shot of compressed air in the drain end.

[AnEv942]

Low point drain per title (plumbing waterline drains) or the drain line on tank as described?

Is it small plastic 1/2 turn ball valve? Line clear tube? if you have access pinching, or milking toward valve can sometimes start flow. Ours if hasn't been opened in a while will clog with scum (white). I wouldn't push it back into tank. Ours runs from front to back of camper though so a lot of non moving water.

With the slightest bit of flow I'll quickly tap valve outlet, stopping water flow, let it flow, tap it again, forcing just a bit of water back up or pulsing water in tube. Doing this quite a few times will generally loosen up the scum, and eventually clear.

I can only assume valve and tube, but if like ours and most Ive seen I wouldn't apply much pressure/vacuum likely just suck tube closed if blocked at tank.

If its the little ball valve though removing it to expose end of tube, ours is barbed, something like a turkey baster to pull and push water would be the most force I'd apply.

[Wardster]

Did you use compressed air at any point? If not, then you should give it a go to see if it will open up the line you think is obstructed.

[NMDriver]

Maybe you left the valve open after draining in a prior year, then bugs like to make nest up in the pipe/valve.

If you can get a pipe wrench on the valve take it off and see if you can clear the clog. I have a 5th wheel, not a truck camper, and my drain valve is easy to access for removal/cleaning.

I use to leave the valve open after winterizing but I learned to close it.

[narcodog]

Snaking may work but there are a lot of twists and turns in the line. I would also be afraid of putting a hole in the tubing. What I would do was blow the line with low pressure air. Using something like a can of Dust Off. If that doesn't work then I would use air from a small compressor.

[thedavidzoo]

get it started with a little suction?

[Flan]

Snaking it sounds good to me maybe some sediment or a flat piece of who knows what right at the exit point of the tank.