I have a black tank problem in my new Jayco trailer. Today it was 2/3 full on the meter and I emptied it, but it didn't empty. It flowed for about 15 seconds and then stopped. I went back inside and it still said 2/3 full. I flushed the toilet a couple of times and went back out and opened the tank again and very little water came out. The trailer is less than 1 month old. I've owned a motor home before and I never had this problem. I've been set up in a park in North Carolina for 14 days now. I've been leaving the black tank closed until it's about 2/3 full and then I empty it and then I back flush it. I've done that about once a week. It's just me using the trailer. I've been leaving the gray tank open because the release valve is up under the slideout. Maybe I have to close the gray tank like I used to do. Maybe there is a long tool they sell to reach a tank handle like that.I filled the gray tank to 2/3 full and then released it. It appeared to clear out some more black tank waste, but not all of it. I went inside and it still said the black tank is 1/3 full. I'm going to go to the store and by some toilet cleaner for RVs and a toilet treatment to add to the toilet. I can try to back flush the black tank, but I'm worried it may overflow. My toilet paper says it is septic safe, but maybe I can't flush any paper in this Jayco. I never had this problem in the motor home I owned for a year. Can you suggest my best way out of this mess?

You still aren’t sure how rv sewer works. Gray won’t flush any black except whats residual in the (typically short) shared section of main line. It basically flushes the sewer hose out and that’s it. Beyond that, tank sensors are not always or even frequently accurate. It’s highly unlikely that you’ve made the poop pyramid and blocked everything up in just 2 weeks of 1 man pooping, lol. You can look down the toilet and see if you have an issue as well as measure depth of fluid retained. It’s a brand new camper so possibility of a construction issue is imo greater than a camper that’s worked the bugs out already. And of course assuming “normal” use and you haven’t used too much poopy paper and not enough water. Go see what’s left in your black tank visually and if it appears to be clogged or building up, filler up about 1/3 -1/2 full and go take the camper on a short drive to break everything up. Dumping chemicals won’t do sht for you. Figuratively or literally. LolI guess another pertinent question is do you know you have a 2/3 full tank of water and baby Ruth’s? Idk your tank size but that much sewage from one person in a week sounds like a lot? Report back when you’ve actually verified what’s left in the tank.

Know your tank sizes. And assuming you don’t have a tank flusher installed, you can fill the black tank either from the toilet valve or just run the hose into the camper and fill up the black tank.

It sounds to me like you have a bad monitor in your black tank which is a pretty common thing. Since your trailer is "new" I am assuming it is under warranty. I would take it back to the dealer. As far as closing your gray tank so it can fill up, that won't help your black tank issue at all. They are separate tanks. I don't understand what you are saying here. It is not a bad practice to leave the gray tank open when you are camped. You should never leave the black tank open though. Let it fill, flush it out and you should be good to go. If the tank is reading "2/3 full" even after you empty it, you have a problem with the monitor.

Either the monitor reading is inaccurate (very common) or they left the cutout of the tank in the tank itself. This happens when they drill the cutout for the toilet and the remining disc drops in the tank and can block it.If you can physically get to the side of the tank, tap on it and see if you can tell if it's really empty. If the monitor is reading bad there are a few methods to try and clean the sensors, the easiest is a black tank flush.Or - they have the dump valves for the tanks labeled incorrectly. Your black lever is really your gray tank and vice versa. In the 4 MH's I have owned, 2 had this issue.

Thanks for the feedback. I don't think the black tank empty because it didn't run as long as the first 2 times I dumped it. The first 2 times were about a minute; today maybe 30 seconds or less. Also, the bathroom has developed a noticeable stink in the last 36 hours or so. Also, I just got back from the store and I checked the gauge. It said 2/3. I went out and opened it and it flowed for maybe 10 seconds. Then I closed the valve and re-opened it and a few more seconds came out. So I opened and shut the valve a few more times and got a few more seconds to run out. It's back down to about 1/3 reading, so the reading is changing.I bought 3 products at the store for RV black tanks. One is RV Digest-It which I think is like Liquid Plumbr for RVs. I also bout the TST Max packets to put in the toilet and a product from Walex called Commando. I'm going to read up on those and see if they help clean it out.As for leaving the gray tank open, they both exit the same dump opening, but they have different handles. I'm sure the black handle is the black tank from watching the clear end on my dump hose. Other campers have told me when they empty into a coming hose (mine do) it's best to dump the black tank first and then dump the gray tank to flush out the hose, and maybe it helped the common exit point because it seemed to flow more after dumping some gray water, but it still reads 1/3 full on the Black tank and empty on the gray.

Black Tank Help Needed | Good Sam Community

Grit_dog
Navigator
Apr 21, 2023
You still aren’t sure how rv sewer works.
Gray won’t flush any black except whats residual in the (typically short) shared section of main line. It basically flushes the sewer hose out and that’s it.
Beyond that, tank sensors are not always or even frequently accurate.
It’s highly unlikely that you’ve made the poop pyramid and blocked everything up in just 2 weeks of 1 man pooping, lol.
You can look down the toilet and see if you have an issue as well as measure depth of fluid retained.
It’s a brand new camper so possibility of a construction issue is imo greater than a camper that’s worked the bugs out already.
And of course assuming “normal” use and you haven’t used too much poopy paper and not enough water.
Go see what’s left in your black tank visually and if it appears to be clogged or building up, filler up about 1/3 -1/2 full and go take the camper on a short drive to break everything up.
Dumping chemicals won’t do sht for you. Figuratively or literally. Lol

I guess another pertinent question is do you know you have a 2/3 full tank of water and baby Ruth’s? Idk your tank size but that much sewage from one person in a week sounds like a lot?
Report back when you’ve actually verified what’s left in the tank.
Grit_dog
Navigator
Apr 21, 2023
Know your tank sizes. And assuming you don’t have a tank flusher installed, you can fill the black tank either from the toilet valve or just run the hose into the camper and fill up the black tank.
aftermath
Explorer III
Apr 21, 2023
It sounds to me like you have a bad monitor in your black tank which is a pretty common thing. Since your trailer is "new" I am assuming it is under warranty. I would take it back to the dealer. As far as closing your gray tank so it can fill up, that won't help your black tank issue at all. They are separate tanks. I don't understand what you are saying here. It is not a bad practice to leave the gray tank open when you are camped. You should never leave the black tank open though. Let it fill, flush it out and you should be good to go. If the tank is reading "2/3 full" even after you empty it, you have a problem with the monitor.
way2roll
Navigator II
Apr 21, 2023
Either the monitor reading is inaccurate (very common) or they left the cutout of the tank in the tank itself. This happens when they drill the cutout for the toilet and the remining disc drops in the tank and can block it.

If you can physically get to the side of the tank, tap on it and see if you can tell if it's really empty.

If the monitor is reading bad there are a few methods to try and clean the sensors, the easiest is a black tank flush.

Or - they have the dump valves for the tanks labeled incorrectly. Your black lever is really your gray tank and vice versa. In the 4 MH's I have owned, 2 had this issue.
DallasSteve
Nomad
Apr 21, 2023
Thanks for the feedback. I don't think the black tank empty because it didn't run as long as the first 2 times I dumped it. The first 2 times were about a minute; today maybe 30 seconds or less. Also, the bathroom has developed a noticeable stink in the last 36 hours or so. Also, I just got back from the store and I checked the gauge. It said 2/3. I went out and opened it and it flowed for maybe 10 seconds. Then I closed the valve and re-opened it and a few more seconds came out. So I opened and shut the valve a few more times and got a few more seconds to run out. It's back down to about 1/3 reading, so the reading is changing.

I bought 3 products at the store for RV black tanks. One is RV Digest-It which I think is like Liquid Plumbr for RVs. I also bout the TST Max packets to put in the toilet and a product from Walex called Commando. I'm going to read up on those and see if they help clean it out.

As for leaving the gray tank open, they both exit the same dump opening, but they have different handles. I'm sure the black handle is the black tank from watching the clear end on my dump hose. Other campers have told me when they empty into a coming hose (mine do) it's best to dump the black tank first and then dump the gray tank to flush out the hose, and maybe it helped the common exit point because it seemed to flow more after dumping some gray water, but it still reads 1/3 full on the Black tank and empty on the gray.
opnspaces
Navigator II
Apr 21, 2023
Sounds like you have some kind of clog in the tank. Possibly the cutout scrap as previously suggested. Did you try turning off the water and then flush the toilet and look down the hole to see if there actually is water in there?
evanrem
Explorer II
Apr 21, 2023
Have you physically looked in the toilet after emptying? If not shine a light down and if you see the bottom of the tank you are good. I stopped relying on the sensors long ago.
Grit_dog
Navigator
Apr 21, 2023
To repeat, you almost assuredly have zero use or need for any of those products you bought.
How much “non liquid” came out? This ain’t your first rodeo.
If the camper was stationary while the tank was being “filled” you should not see the chunky chocolate milkshake as much as you should see some discernible tissue and baby Ruth’s.
If it’s just the liquid gettin out I’d subscribe to the cutout plug may be blocking the outlet.
But you can at least temporarily cure that by taking it for a drive and gettin the “stuff” moved around and easier to dump. Because it will likely move the disc if it’s causing the issue.

From reading your posts for years, I know you sometimes have a habit of asking for advice and then doing your own thing. Maybe someone else will validate this advice and save you some headaches if you follow it.
Boomerweps
Explorer
Apr 21, 2023
There is a sewer fitting that’s clear and has a garden hose inlet. You can use this to flush the drain lines out. Worse case, you can backfill your tank this way and see if it pushes any blockage around.
wa8yxm
Explorer III
Apr 21, 2023
It empeied the 2/3 full Mine said that for over 15 years only with extreme effort could I get it to drop down to 1/3 and it only read empty twice once when new and once after an extreme cleaning.

The sensors are a joke if you really want to know how ful it is SEE LEVEL (google it_)

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