Community Forums

michguy · 01-31-2014, 02:08 PM

I have a 2005 National Tropical T370. I filled it recently anticipating a few nights of boondocking which we didn't do. We've not drawn water from the tank with the water pump at all, and have been hooked to City Water for 6 days.This morning I hit the Tank Level Monitor switch, and it showed 1/2 full. Although the other Tank level Indicators lie constantly, the Fresh Water one has so far seemed quite reliable. I switched over to Tank Fill and was somewhat amazed that the tank took quite a bit of water, since I didn't think we had been drawing off the tank. Can someone explain to me how the water system works. I have no Owner's Manual, and it seems to me that somehow we are drawing off Fresh Water tank while on City Water. We have no leaks ...evident.

BFlinn181 · 01-31-2014, 03:02 PM

You could have a valve that doesn't completely shut off the tank when on city water, but I'd think the pressure would overfill the tank. The other possibility is that the overflow drain on the water tank is creating a syphon and draining the tank. Place some weighted sheets of newspaper or paper towels on the ground under the overflow drains and watch for water.

mel s · 01-31-2014, 03:34 PM

Quote:

Originally Posted by michguy

I have a 2005 National Tropical T370. I filled it recently anticipating a few nights of boondocking which we didn't do. We've not drawn water from the tank with the water pump at all, and have been hooked to City Water for 6 days.This morning I hit the Tank Level Monitor switch, and it showed 1/2 full. Although the other Tank level Indicators lie constantly, the Fresh Water one has so far seemed quite reliable. I switched over to Tank Fill and was somewhat amazed that the tank took quite a bit of water, since I didn't think we had been drawing off the tank. Can someone explain to me how the water system works. I have no Owner's Manual, and it seems to me that somehow we are drawing off Fresh Water tank while on City Water. We have no leaks ...evident.

michguy
Here are 2 possible reasons:
1.) On some coaches water sloshes from, (or siphons out of), the water tank through the overflow/vent, when traveling...... (I can, and do, lose/waste as much as 30 gal from a full 100 gal tank before I get to my destination).

2.) When I have the 12V water pump turned OFF my coach will not use any water from the on board tank.
However, even when I'm on city water, if the 12V power to my water pump is turned ON, (accidentally or purposely), I use some water from the fresh water tank.

Mel
'96 Safari

michguy · 01-31-2014, 04:02 PM

Mel,
I never considered the possibility of water siphoning or sloshing from the overflow pipe, but I think you've nailed it. I check for water leaks (paranoid) nearly every day, and haven't noticed a single drop. Winter before last, we were in Apache Junction, and I found that I had a leak between my Rank Fill and city Water and the tank kept overflowing, so I had the valve replaced.
Time to stop pondering. Thanks !!

Michguy

wa8yxm · 01-31-2014, 06:12 PM

Are you sure you did not leave the water pump on? I have done that. and when I do .. You already posted what happens.

chboone · 02-01-2014, 03:42 PM

Another possibility is if you have two tanks like mine does and you run the water fast when filling only one tank will be full when water starts running from the overfill. The water equalizes slow between the two tanks. Wait for about 5 minutes and try filling again. If you can add a lot more water that part of your level problem.

Chuck