The dreaded potty burp, can't eliminate it

[Wind_Surfer]

Long time RV'r and have dealt with the potty burp before but this time I can't figure it out. Interestingly the pipe connecting the toilet to the tank would sometimes back up implying a 'pyramid'. I would take the cleaning brush and 'push' at the water and it would clear. Pipe to tank is about 3 feet in length.

I have (gently) snaked both the toilet and vent. As far as I can tell there is no "PYRAMID" and the vent is clear.

We have always used plenty of water during usage and have had this rig for 5 years.

Thoughts?

[Veebyes]

Took the cap off the top of the vent on the roof & poured a couple of buckets of water down the vent pipe. Whatever was in there got washed into the tank then drained at the next dumping. No more burping.

[mr__ed]

Beaker wrote:
My old fifth used to do this. It had a curved pipe and when getting full it seemed like the tissue would start backing up in the pipe. It would burp and when this happened I know it was time to dump although if I "pushed" it like you did, I would get a couple more days.

Same here with a motorhome I used to own. When flushing, I would notice a bubble coming back at me. That was a clue to empty the tank because my level sensors had long since stopped working.

[Old-Biscuit]

Pressure coming out of Drain Blaster is limited to amount of pressure used.
If you have a water pressure regulator in use then Drain Blaster can NOT increase that pressure.

Using it would be similar to using a tank flush system....and should be done with drain valve OPEN.

If one doesn't use a LITTLE common sense then they end up with what they have brought on themselves


:S

[westend]

myredracer wrote:

westend wrote:
You may wish to review what that Liquid Drano really is. The MSDS shows it contains lye and other corrosive materials. It definitely isn't friendly to metal pipes.

Our KZ onwers manual says to use Liquid Drano.

This Drano info. says "Safe for plastic, PVC, metal pipes, garbage disposals, and septic systems." Drano says all of their products are safe for plastic and metal pipes here as well. The Liquid Drano Max Gel that we've used says safe for metal and plastic right on the label. Does have lye in it but also bleach, a corrosion inhibitor and a proprietary ingredient. The MSDS sheet doesn't say anything about being safe or not on plastic & metal.

A google search shows 6 different types of Drano in a liquid form - Drano Max Gel, Drano Liquid, Drano Max, Drano Clog Remover, Drano Pro Concentrate and Drano Max Build-up Remover. I didn't know there are so many but all are supposed to be okay on plastic & metal. Have also used Liquid Plumr and it said on the label it's safe for metal and plastic label as well.

The chemical drain cleaners are all, AFAIK, corrosives. There may be some acidic ones but I haven't used any of either for years. There was, at one time, a big push back on using chemical drain cleaners and there was good reason, for the most part. Nearly all drains in a house can be easily cleaned without the use of chemicals.

Hey, use what works for you. Letting the Drano only sit in a drain or tank for part of an hour before immediately flushing isn't going to hurt any of your pipes. Letting it stand in metal pipes isn't advised. I've replaced plumbing in houses that have used corrosive drain cleaners.

I really can't see using any chemical cleaners in an RV system. I sure wouldn't want them in my drain hose. I use some dish soap and the cheapest water softener I can find to scrub up my tank, occasionally.

[Wind_Surfer]

Thanks to all for the information and suggestions!!

As of today (qualifier; 'today'), the burp has disappeared. Maybe messing with everything; multiple flushing, flushing the vent pipe, snaking the vent and potty, has somehow giggled something.

I will keep my fingers crossed.

[Chrisatthebeach]

Old-Biscuit wrote:
Tank burps when empty after dumping and cleaning.


That is a blocked/obstructed VENT line.

UNLESS toilet line to tank is NOT emptying

Go to Home Depot/Lowes/ACE Hardware and purchase a 'Drain Blaster'
Screws onto a garden hose, push it down toilet line and turn on water. It will expand to size of line sealing it and then blast away with high pressure clearing out line.
Then if toilet stills burps.try it on vent line from roof

They have 3 sizes...get the 1 1/2" to 3" model

I actually used this when I had the same problem with the Jayco. It worked. I bought this unit used and it seems the original owner did not use a lot of water, there was build up in the bottom of the tank and this took care of it.

[johnhicks]

I saw a guy explode his black tank with a Blaster. Wasn't real purty...

[D_E_Bishop]

To Wind Surfer, I have no idea what fitting was used to accept the usual 1.5" vent pipe so this may just be impossible but as diagnosed, the is a gas built up so it's not venting. If the fitting on the top of your black tank is a simple slip fitting without a stop, yes they do exist, the pipe may extend down into the tank instead of stopping inside the fitting.

This is just a guess. I am not a plumber and I have never bought the fittings but mine look like flanges, sealed to the top of the tank and screwed down. What I would do if it is a straight drop into the tank, is to extend a 3/4" or 1" measuring tape down into the vent pipe and try and hook the end on the bottom of the pipe. Record the measurement and then extend it fully into the tank and when it touches the bottom, record that measurement. Compare the two measurements. The answer should be obvious, if they are very close, it could be the rising water in the tank is sealing off the vent.

In atperci's problem, measurements are impossible because, from his description the vent is combined with his grey water tank. His easy test is to use a tapered sewer hose fitting to adapt the stinky slinky to the sewer line, adapt a wet dry vacuum hose to the fitting, place the tapered fitting in the drop hole in the toilet and attach the hose to the exhaust of the vac and turn it on. If the air from the vac flows out the vent, add say 5 gallons of water until it won't vent any more. This would give him an estimate of what the volume of his tank really is and show that the vent is working.

I would appreciate any feed back you might have if you try my ideas.

David

[atperci]

Here's our problem on our MH, we have the dreaded burp, and the small geyser of water that goes with it. Our tanks our as clean as can be expected and it burps usually after a couple of days of use, indicating waste gasses. Suspecting the vent was blocked, I ran a hose to the roof and it flowed right through. Or so I thought.

Turns out the black and gray vents are combined at some point between the roof and tank, so all that water went into the gray tank and backed up into the shower pan! Yikes!!! I quickly turned off the water and opened the valve before it overflowed.

Since I have no idea where the wye fitting is, how can I check the vent to the black tank? Any ideas?

[myredracer]

westend wrote:
You may wish to review what that Liquid Drano really is. The MSDS shows it contains lye and other corrosive materials. It definitely isn't friendly to metal pipes.

Our KZ onwers manual says to use Liquid Drano.

This Drano info. says "Safe for plastic, PVC, metal pipes, garbage disposals, and septic systems." Drano says all of their products are safe for plastic and metal pipes here as well. The Liquid Drano Max Gel that we've used says safe for metal and plastic right on the label. Does have lye in it but also bleach, a corrosion inhibitor and a proprietary ingredient. The MSDS sheet doesn't say anything about being safe or not on plastic & metal.

A google search shows 6 different types of Drano in a liquid form - Drano Max Gel, Drano Liquid, Drano Max, Drano Clog Remover, Drano Pro Concentrate and Drano Max Build-up Remover. I didn't know there are so many but all are supposed to be okay on plastic & metal. Have also used Liquid Plumr and it said on the label it's safe for metal and plastic label as well.

[westend]

myredracer wrote:
I'd also try cleaning the tank back to factory fresh, factory clean by using some Liquid Drano and seeing if that helps. Will need to drive a little to make it slosh around. A thorough flush & clean every time you dump may help using an in-tank flusher, wand and/or backflush elbow. You might try taking a hose up onto the roof and putting water down the vent pipe (with valve open) and seeing if it backs up.

We used to have a problem with a pyramid at first until we figured out we needed to add a few gallons of water before using and doing a good flushing/cleaning job before heading home after a weekend trip. Our toilet pipe drops straight down into the tank and is very short. We also use Liquid Drano once or twice a year and it doesn't attack plastic or metal (including seals).

Some tanks are simply harder to dump and flush due to their size, shape and outlet location on the tank and take more effort to clean regularly.

You may wish to review what that Liquid Drano really is. The MSDS shows it contains lye and other corrosive materials. It definitely isn't friendly to metal pipes.

[myredracer]

I'd also try cleaning the tank back to factory fresh, factory clean by using some Liquid Drano and seeing if that helps. Will need to drive a little to make it slosh around. A thorough flush & clean every time you dump may help using an in-tank flusher, wand and/or backflush elbow. You might try taking a hose up onto the roof and putting water down the vent pipe (with valve open) and seeing if it backs up.

We used to have a problem with a pyramid at first until we figured out we needed to add a few gallons of water before using and doing a good flushing/cleaning job before heading home after a weekend trip. Our toilet pipe drops straight down into the tank and is very short. We also use Liquid Drano once or twice a year and it doesn't attack plastic or metal (including seals).

Some tanks are simply harder to dump and flush due to their size, shape and outlet location on the tank and take more effort to clean regularly.

[Wind_Surfer]

Agreed that it has to be the vent pipe. I'm pretty sure I got the right one but will re-evaluate today.

I have used the drain busters before but not in an RV.

[beemerphile1]

Old-Biscuit wrote:
...push it down toilet line and turn on water. It will expand to size of line sealing it and then blast away with high pressure clearing out line.....

and pray it doesn't blow the pipes apart and cause further damage. You take a big risk using that thing.

OP - it sounds like the vent pipe is clogged, are you certain you checked the correct vent?