Black tank filling fast

[JimWoods]

The wife and I full time in our alpine 40 fdts, we've been in it about 11 months. The last couple weeks our black tank has been filling in 2 days. I leave a tank flush hooked up but have 2 valves in line closed and drain water from the line so it doesn't hydrostat after flushing. Is anyone aware of how else my black tank can fill besides spray nozzle and the toilet itself? After I dump the tank I do fill it via spray nozzle for 8 minutes to give it fresh water to start floating solids away.

Jim

[Jon_C]

My camping buddy recently found out their bathroom sink drains into black tank in their truck camper

And just for grins I would disconnect the fill hose just to verify both valves aren’t leaking somehow

[wolfe10]

Jim,


Are you determining full by a gauge? By volume in tank when you drain it?

[Alpine36]

Occasionally, we have experienced plumbing restrictions from the toilet to the black tank before. It make it appear the tank is nearing full capacity, when in reality waste is just hung up somewhere downstream in the toilet drain plumbing. (Alpine toilet doesn’t sit directly above the waste tank)
A simple quick snake out corrects the problem. This has occurred only while we’ve been “conserving” water, basically dry flushing…not a good idea.
FWIW, our black tank level sensors are not very accurate. I’m not sure what else drains into the black tank, but two of us can easily go about a week “dry camping” before it needs to be emptied.

Are you sure the black tank is actually filling?
It should be an 80 gallon tank. That’s a lot of action in two days.

[JimWoods]

So we will notice before it comes full that it starts burping up the toilet when we flush so I figured the level is up to the vent.

[Jon_C]

Mine does that when theres a pile builtup directly below the toilet even tho tank is mostly empty.

Ive had to use a stick to get it out of the way. Now my wife knows to fill bowl with more water before flush so it spreads out in tank. Rarely happens anymore

[Alpine36]

Originally Posted by JimWoods

So we will notice before it comes full that it starts burping up the toilet when we flush so I figured the level is up to the vent.

That’s exactly what happens with said restriction I described.
I carry a small fish tape, try running it down the plumbing from the toilet a couple times, with a bunch of water. Somewhere in line to the tank is an air admittance valve union. Methinks this is where your restriction is.

[Old-Biscuit]

Originally Posted by JimWoods

So we will notice before it comes full that it starts burping up the toilet when we flush so I figured the level is up to the vent.

Originally Posted by Jon_C

Mine does that when theres a pile builtup directly below the toilet even tho tank is mostly empty.

Ive had to use a stick to get it out of the way. Now my wife knows to fill bowl with more water before flush so it spreads out in tank. Rarely happens anymore

Originally Posted by Alpine36

That’s exactly what happens with said restriction I described.
I carry a small fish tape, try running it down the plumbing from the toilet a couple times, with a bunch of water. Somewhere in line to the tank is an air admittance valve union. Toilet drain line to tank is free flowing---no Air Admittance Valves/unions (AAVs are on Sink Drain Lines after 'P' Traps) Toilet drain can have 45* elbows that can catch TP/StuffMethinks this is where your restriction is.

If toilet burps it means tank is full enough to obscure vent line or you have poop pyramid

Poop Pyramid will cause toilet to burp but that will happen all the time until poop pyramid is removed

Running flush system for 8 MINUTES after dumping so tank has water could be some of your problem.....that's a lot of water going back into tank
**Couple full toilet flushes is more then enough to keep tank bottom wet

Leaving flush hose connected......that could be some of your problem
Disconnect when not using so NO water can go in thru valves that might be leaking


Burping can also be due to Vent Line being blocked
tank might not actually be FULL but high enough to block off vent line causing toilet to burp
Vent line Might have slipped down into tank so it gets blocked when tank is only partially full
*Check roof vent.....end of pipe should be flush with roof line
If it is lower then vent has slipped down....grab with pliers and pull back up flush then secure with couple screws into roof/recaulk

[Alpine36]

Originally Posted by Old-Biscuit

If toilet burps it means tank is full enough to obscure vent line or you have poop pyramid

Poop Pyramid will cause toilet to burp but that will happen all the time until poop pyramid is removed

Running flush system for 8 MINUTES after dumping so tank has water could be some of your problem.....that's a lot of water going back into tank
**Couple full toilet flushes is more then enough to keep tank bottom wet

Leaving flush hose connected......that could be some of your problem
Disconnect when not using so NO water can go in thru valves that might be leaking


Burping can also be due to Vent Line being blocked
tank might not actually be FULL but high enough to block off vent line causing toilet to burp
Vent line Might have slipped down into tank so it gets blocked when tank is only partially full
*Check roof vent.....end of pipe should be flush with roof line
If it is lower then vent has slipped down....grab with pliers and pull back up flush then secure with couple screws into roof/recaulk

Yeah, probably right, no AAV in line, but there is something in line between the toilet and waste tank where Alpines get restricted. I can “feel” it with the snake. It may be the washing machine drain tee? Anyhow, running the snake down the plumbing from the toilet to the tank a few times has resolved described problem every time for us. Burping toilets sure do get your attention lol…

[lazybyrd]

After removing my toilet and the outside panel exposing the toilet plumbing I found the top of the black tank had collapsed a bit where the toilet drain pipe enters the tank. Also found that the drain from the toilet extended below the surface of the tank via the rubber grommet fitting. These two issues combined to reduce the clearance between the bottom of the toilet drain pipe and the bottom of the tank. I shortened the drain pipe a bot and replaced the grommet. I also make sure to add water to the tank as some others have mentioned to aid in the collapse of the effluent as it hits the bottom of the tank.
Hope this is some help.

[andy29847]

In my 38' Alpine, the tank is directly below the toilet. It seems no matter what we do, if we are in the same spot for a week or more, we get the infamous poop pyramid. We do some things to make it a little better. We only put the really messy paper down the toilet. The rest goes in the trash can. We flush frequently. More water seems to help. When the toilet starts burping, I get my awning rod and some Clorox wipers together, use the rod down the toilet to break up the Pyramid, and the Clorox wipes to clean off my rod as I remove it.


Also, I often do not dump when leaving a camping spot. I like to dump when the tank is over half full and after driving for a spell. Driving turns the mess into soup.

[lazybyrd]

The movement of driving also dissipates the pyramid.

[Jim A]

I have found that using a plunger in the toilet will at least temporarily fix the burp problem. You can hear and feel when the restriction has been relieved. It will return in relatively short order until you have fixed the root problem, but it can give you a few flushes to a more convenient time to fix the issue.