Toilet pipe cleaning

[jbrack]

I have a 2018 5th wheel and currently a full-timer. My blackwater tank has a flush system which I use religiously every time I dump. Recently I've noticed that occasionally when I flush the toilet with the foot pedal I get a small "burp" back up through the pipe which I suspected was a gas back up, even though I don't smell anything. I checked my roof-top vents and there are no obstructions. When I look down through the commode into the drop pipe, there is a buildup on the inside walls. I'm not sure if this is causing the burp or not and I have reached down through the toilet was far as I can with a hand brush. I also strung a hose inside with a high pressure nozzle but the build-up remains. I thought about pulling the toilet and using a 4" stove pipe brush but I'm not sure this is even my problem. Does anyone have an idea what I should try next?

[Dave_H_M]

Try the easy thing first. go to wally world and get one of those flexible wands with the whirly thing on the bottom of it.

My guess is that it will destroy the pile at the end of the pipe down in the holding tank and all will be well.

[ScottG]

jbrack wrote:
There are only two of using the toilet. I never dump my tank until it is at least 2/3 full. I checked the roof-top vent pipes for obstructions by climbing up there, removing the cap and looking down the pipe with a flashlight....it appeared all clear. When I dump there is no issue and every thing roars out through the pipe like it should, which I though if it didn't, that would indicate a vent pipe issue.

You cannot see if the vent pipe has slipped down into the tank (as Dutch described) or just as likely, was installed too low to start with.
If you only have this problem when the tank is half or more full, you probably have a vent pipe that's too low in the tank.

The other thing I have seen is the pipe is too high up into the roof cap and is blocked. I freed one up by just cutting some V's for air to get in.

[jbrack]

There are only two of using the toilet. I never dump my tank until it is at least 2/3 full. I checked the roof-top vent pipes for obstructions by climbing up there, removing the cap and looking down the pipe with a flashlight....it appeared all clear. When I dump there is no issue and every thing roars out through the pipe like it should, which I though if it didn't, that would indicate a vent pipe issue.

[Old-Biscuit]

'AIR' has to be expelled from tank in order for 'liquids' to enter

That is what the roof top vent is for

Burping back up thru toilet means VENT is NOT venting......hence the 'venting' up thru toilet

Vent line is either:
*Obstructed....how/what did you do to verify it was clear?
*Slipped down into tank so that when level rises the vent becomes blocked and then toilet becomes the pathway to vent


OR the toilet line to tank is being 'blocked'
How are you/others actually using toilet?
Quick/limited flush OR fill the bowl up and let if flush/then run for couple seconds?

Water during usage is your friend

Flushing via tank flush system is not necessary every time provided you let tank get full before dumping
WHOOSH!

[Merrykalia]

The dreaded "burp" is a good indicator that you have a toilet tissue teepee built up inside your black tank. Not using enough water when flushing will cause this. No matter how much flushing you do when emptying, this will occur.

We found this youtube video that was great and got rid of the teepee quick and easily.

Ours burped for quite a while before it built up enough that nothing was getting through. It was pretty awful.

Hope this helps.

YouTube - unstop an RV toilet

[donn0128]

Sounds like a dreaded poo pile. How much water do you use? How often do you dump? How many people using the toilet?
RV toilets dump into a holding tank. To keep things flud they need lots of water. They also need to be dumped when at least 2/3 full. Fuller the better.