Black Water Back Up

wjhgolf · Post by **wjhgolf** » Mon Mar 19, 2012 8:50 am

So, our BW tank showed 2/3 full and we decided not to use the toilet again until last night only, which we never got a chance to do. We proceeded to wash dishes after dinner and use some water in the bathroom sink, but have NOT showered since arriving at this campground - using the campground showers instead. Our GW tank only showed empty, but was probably almost 1/3 full. All of a sudden, after doing the dishes last night, we had a couple of inches of water in the shower, which did smell a little, but did not appear to be raw sewage. Was it our BW tank backing up and even though the BW showed only 2/3 full, maybe it was completely full? How accurate do you find the indicator lights to be anyway? Thanks much!

tomdclark · Post by **tomdclark** » Mon Mar 19, 2012 9:33 am

On our 2005 24RB the toilet and bath sink drain into the BW tank and the shower and the kitchen sink drain into the GW tank.

If you did the dishes in the kitchen before the water showed up in the shower, it sounds like the GW tank was full. It is possible, of course, that there is some sort of blockage before the GW tank which would cause the kitchen water to go directly into the shower, but I suspect this is unlikely.

If you were using the bathroom sink, I don't understand how water showed up in the shower.

I've never had much of a problem myself with the tank indicators, but by reputation they are not very reliable indicators of the actual situation.

mockturtle · Post by **mockturtle** » Mon Mar 19, 2012 9:54 am

My bathroom sink also drains into the black water tank and I'm glad, because my black water tank is a lot bigger than my grey water tank.

al1florida · Post by **al1florida** » Mon Mar 19, 2012 7:57 pm

No way should the shower drain into the black water tank. The gray water does smell a little, but not nearly as much as black water. So the water backing up in the shower would smell a little.

As far as the black water level is concerned, I get a flashlight, turn off the water pump (or shore water faucet) then step down on the toilet flush lever and shine the light down and see just how full the black water tank is.

Works much better than the monitor panel.

The gray water tank monitor gauge is usually pretty accurate.

harrisgowing · Post by **harrisgowing** » Mon Mar 19, 2012 10:12 pm

We have a RSB so our experience is different because I don't think our gray water ever dumps into our black tank, but early on a good tip on this forum is what we live by. We don't hook up to the cg water supply but fill the water tank and use the BF water pump and our inboard tank as our supply. Our sensors are pretty much worthless but when we have emptied our 35 gallon onboard water tank, we know that our gray is probably 2/3 full and the black about half full, from our usage behavior. That is conservative. Our gray tank holds 35 gallons and the black 21 gallons. No accidents in 7 years.

Dallas Baillio · Post by **Dallas Baillio** » Wed Mar 21, 2012 7:36 pm

Here is a link that will help you determine which water source feeds into which tank.

http://www.bornfreervclub.org/bulletin_ ... capacities