burping toilet

We have been full-timing in our 2007 Bighorn since it was purchased new. Recently it has developed a strange problem of the toilet "burping" so violently when it is flushed that liquids are ejected out and over the top of the toilet onto the floor. We have taken a hose up on the roof and flushed out the vent pipe (no obstruction found) and it happens even when the tank has just been emptied. Can anyone help with this?? Thanks.

I've heard of them burping when they're close to full but never when empty. Have you tried running a snake down the toilet flush hole to check for obstructions there? Sorry, but no other possibilities come to mind.

When you ran the hose down the roof vent pipe, did you verify the water was going into the black tank? My only suggestion would be to run the hose in the roof vent high volume to verify there isn't a small obstruction? It sounds as if there is not enough air make-up to the tank when it is being drained. As you know, burping is usually caused by the lack of proper venting of the tank black tank.

Have you watched the movie, RV?

Beader, I've just thought of another potential problem. If you've been in the rig for 2 years now you may have the peverbial "pile of pucky" as it's been referred to in other posts. It's when the solids build up in the tank right below the toilet pipe. Eventually they build up to block the pipe. Liquids seep through but solids pile up. I'm not trying to suggest your black tank dump methods are wrong but if you've been using the rig for a couple years and this problem has just begun, I can't think of where else a lack of air would come from. Unless like previously mentioned by fishin2damax and your vent pipe is plugged. If you can get a snake down the tube and that's your problem, the snake should help clear it out.

Just something to try, fill your toilet all the way to the rim with clean water and flush. The toilet in our Landmark was doing this from new and we also could smell sewage in the coach, this cured it on ours. I suspected the vent pipe was plugged and this put enough pressure on it to blow it clear.

Don

First, let me say "Yuck!!!.

I'm with fishin2dmax. On our rig the vent right over the toilet, goes to one of the grey tanks.
TimK

timk, thanks for that information., We have tried everything that's been suggested and thought the vent pipe directly over the toilet would naturally be to the black tank. That is the next thing we'll check. We appreciate everyone's input.

Just wanted everyone to know that we found the solution to the burping toilet. We had put the hose down the vent pipe twice with no success but, as Timk suggested, it was the wrong pipe. The one by the toilet went to a gray tank and the black water vent pipe was on the opposite side of the trailer!!!! The problem is now solved. Thanks for your help.

So what was it? Was the vent pipe blocked? Buildup of solids?

The problem was obstructed vent pipe. Don't know what obstruction was but with one rinse down the pipe with a hose, there was no more "burping".