Fresh Water Tank Won't Drain

[Richardrky]

My motorhome has been sitting since late April because of the Workhorse brake issue. Yesterday I tried to drain the fresh water tank because the water smelled bad - I mean really bad! There is a tee at the bottom of my fresh water tank. One arm goes to the water pump and the other arm has a valve with a drain hose connected to it.

When I opened the drain valve the water ran out 30 seconds or so and then stopped. I tried opening the fill value thinking there may be a vacuum lock but that didn't work either. I tried opening different faucets to no avail.

After much frustration I finally hooked to the house water system and starting filling the tank up. When I did this the water would flow from the drain vave. I then shut off the water supply and the tank kept draining.
Does anyone know what is going on?
Also why does the water pump run continously when the fresh water tank fill valve is in the fill position?
Thanks

["007"]

Each tank, 2, has a drain that runs near the fill hose line into tank down through the compartment through bottom of compartment outside under your coach. You will see the overfill rubber tube under the coach also.The valves near your water pump are for diverting antifreeze when you winterize.
The water pump will run while filling fresh water tank if you have a switch thrown for pump. You have one in water bay, your bathrooms and in your display area for your tank levels. I have four switch's because I have two bathrooms.
With your coach sitting so long your drain line may have gotten mud dabbers in it and just run a wire up through drain to clear out line.
You should add some bleach in you empty fill water hose and fill your fresh tank than run the bleach water through lines, water heater, all your faucets & showers and let set for a day or so. Than drain bleached water and fill everything with fresh water a couple of times to remove bleach taste. If you have a filter in whole house filter remove it and buy a new one.
I'm using my coach 03 Workhorse just to keep systems working and enjoy the summer Brake recall will give me new calipers which I have not had a problem with because of use.
If you need any more help just ask.

[Richardrky]

Thank you "007" for your reply. As far I know I have one fresh water tank. The drain I tried to drain the tank with was the one right at the bottom of the tank. I can see where it enters the tank. I have used it before to drain the tank. I did look for dirt dobbers.

The water ran out of the tank for 30 seconds or so and then stopped.

Thanks for the bleach suggestion. I was going to sanitize the water lines but I couldn't figure out how to get any bleach in the water tank. I believe you are telling me to fill the fresh water hose that I connect to the tank fill line with bleach and do it that way. Will that be enough bleach in the tank? I'm not sure how much bleach I can actually pour in to the water hose.

Can you tell me why the water pump runs continously when the fill valve is in the fill position?

I also have a bath and a half. It is a 3740.

Thank you!

["007"]

When you put bleach in empty water hose before connecting to water intake the bleach also cleans out your water hose. Just need a 1/3 cup in empty hose and fill fresh tanks full.
You should have two tanks with a 1 1/4" pipe feeding between the two, mounted both sides of chassis rails of your coach. Each tank will have a drain valve. 2nd tank drain will be in compartment thats under your refridge vent.
You have four switch's also as I,same coach, look in tank level display area the green light should be off, if on you have a switch operated.
Gave you four locations previous post.
Any time that green light is on even when your hooked to water faucet at CG your pump will operate, have it turned off no need to be on with water hook up.
Poor drainage you may have a piece of plastic in tank blocking your drain line.
I would run a #14 black wire up through the drain pipe with valve open and push wire up into tank you should see wire in tank beyond drain hole in tank.
Not likely but you may not have air in tank the over fill hose's maybe sealed to tight and air cannot get into tank for drainage. The flat rubber part needs to be opened so air can get in tank. Just squeeze and clean if stuck together.

[Richardrky]

Thanks again!
I will look for that second tank and I will try the things you suggested.

Richard

["007"]

The tanks are opposite each other both sides of coach.

[Max Hubrich]

Richardrky,

I would put a air gun nozzle on the lower end of the drain hose, with about 40 PSI and let her have it! Make sure the valve is in the open position, ie handle parallel to the drain line.

Were you using well water, or some other source in your last outings? If you were on "city water" you shouldn't be having these problems. The chlorine in city supplied water should have taken care of this problem. The above mentioned procedure by "007" will get you going again.

Good luck,

[Richardrky]

Now that you mentioned it Max, I did fill the tanks with well water from my son-in-law's farm back in April before my trip to Charleston, SC. I guess the water system needs the cholrine from the city water.
Another lesson learned.
Thanks!

[Max Hubrich]

Richard,

As a very (low cost) unscientific test, do this:

Get two, 2 liter empty, clear plastic bottles. Fill one with the questionable well water (mark it with a magic marker) and fill the second one with a city water source. Let them sit in a dark place for 6 months or so. Use the water in the fresh water tank, if you still have some.

Give us an update sometime down the road-

Cheers,

[BCook57]

The water pump runs continually when you have the fresh water fill selected because one of the water pump switches somewhere in the coach is turned on. In my '07 DSDP there are 4 places to turn off, including the switch in the water bay. Once turned off, the pump won't come on and the tank will fill more quickly.