3750FL Black Tank Rinse

[bleedmichigan]

First Hello and Thank you for any assistance.
My wife and I just upgraded from a travel trailer to a 3750FL 2011 in great shape. We had the travel trailer for about 10 years and now our kids need more space. In anycase I went through everything and the only issue I found was the black tank flush does not seem to work. Either the end in the tank is clogged or the check valve/back flow valve is bad. Does anyone know where Keystone might have located the check valve on the 2011 3750FL. I checked the bathroom sink and it wasnt under there, so any assistance on locating it would be helpful. Otherwise I will check the tank sprayer as I know where that is located.

Thanks in advance.

[BB_TX]

Also look under the kitchen sink. And someone posted they found theirs behind the convenience center, but I don’t remember the floorplan. Another possibility would be in the wall behind the shower. If you can see under the shower and see 4 pipes going up where you would expect to see only 2 (hot and cold) then that is likely it. But a failed flush anti siphon valve normally leaks rather than blocks flow.

[twindman]

My backflow totally stop the flow, so I just uninstalled it under the bathroom sink.

[bleedmichigan]

Originally Posted by BB_TX

Also look under the kitchen sink. And someone posted they found theirs behind the convenience center, but I don’t remember the floorplan. Another possibility would be in the wall behind the shower. If you can see under the shower and see 4 pipes going up where you would expect to see only 2 (hot and cold) then that is likely it. But a failed flush anti siphon valve normally leaks rather than blocks flow.

Thanks for the ideas. I checked the sink and its not there. I will have to check under the fridge and shower.

[BuilderBob]

If you pull the back wall off in the basement you can fallow the water line from the black flush connection and get an ideal of wear it is at.

[footz1941]

Normally red line is hot water Blue is cold water and white goes to the check valve. If you find white lines in the basement cut them off and connect them back together in the basement End of problem