Doesn't make sense???

[roaddawg]

So I had a completely empty black water tank. Or at least I believe it is. The control panel indicates full, so I drained it and only a gallon or so of water came out. This was about what I had added to the toilet.

So, with an empty tank, I added some cleaner to hopefully clean the sensors so they would work. Instructions indicated to fill the black water tank half way or more. I turned on the water pump, stepped on the toilet flush, and water sprayed with good pressure. After about a gallon or so of water, the water level rose into the toilet bowl. I let it sit for about and hour and it didn't drain down. I emptied the black water tank, and approximately the same amount of water drained out. However, there is still water in the pipe below the bowl and in the bowl itself.

I used a 10 foot snake and it seemed to go through the toilet and pipe without any stoppages.Water began to leak from the area of the foot pedal as it was still standing in the bowl and pipe.

At the same time, and I don't know if it is connected, water was leaking from the city hookup on the outside of the coach.

Any ideas what is going on??? What should be my next step in trying to figure out why the water in the toilet is not draining. The sinks and shower work fine. When I drain the gray water it all comes outs.

Thanks for any advice or suggestions.

[Judge]

I’m assuming you have verified that your drain valve is opening fully. And also verified you don’t have two valves for your black tank (some coaches do and both must be opened). You don’t say what coach you have but I know some Class C’s do have two black tank valves. The second valve is usually on the passenger side.

Also, there is a possibility that there is construction debris in the tank causing a blockage. I can recall that a 3” round piece of plastic came out of the black tank on my old Outlaw 29H. Someone at the factory used a hole saw to cut a hole in the tank and they let the platic just drop down into the tank instead of removing it.

Finally….. If you are not regularly using full bowls of water to flush, you may very well have some damming further into the tank from waste buildup.

You may want to try working a snake in again as far as you possibly can.

You might also want to try and pour some RidX into the tank along with some water. Then drive around a bit to mix it up. Then let it sit and try to break down the waste. Then add some Calgon Water Softener and Dawn and then drive around some more. Then open it up and see what happens.

I’ve never had a black tank issue by following these rules (but this is not dry camping friendly) since we usually have full hooks ups:

Going #1? - Use a 3/4 of a bowl of water to flush. This is important to help keep pushing waste well down into the tank.

Going #2? - Use 1 full bowl after going and another full bowl after wiping.

You need to think about how your toilet works at home. You need plenty of water to push the waste downstream. Otherwise your making wallpaper paste in the tank. Water is your friend and ensures the waste makes it to the bottom of the tank so when the tank is full of water it forces everything out of the tank.

Then to keep the tank and sensors clean, we do the following:

1. Drain the tank.

2. Use the SaniFlush to fill the tank 80% full with fresh water and then drain again. I will do this a second time if I still see a lot of debris coming out of the tank.

3. Then add 5 gallons of water and add Calgon Water Softener, Dawn Soap and RV Septic Tabs to the empty tank. This mix sloshes in the tank while driving to help keep the sensors clean and the Calgon makes the walls of the tank very slick.

[10scDust]

Aside from the very good suggestions posted by Judge, one thing I have heard works for cleaning the sensors, is to drive with a bag full of ice emptied into the septic tank.
I haven't tried it personally, but I can imagine it doing the job.

[Jimbo56]

We had a 5 th wheel with cables attached to the handles. The tanks were a pain to empty as the cables would slip ( unbeknownst to me at the time). After rerouting the cables (wider turns) and using loctite , no more issues. Also, if while at a campground, you keep your black valve open, you may have a sludge dam that has built up blocking the drain.

[lwmcguir]

Excellent summary Judge

[roaddawg]

I'll try these suggestions. This is a 2016 Thor Class C, four winds 28Z. Bathroom is on passenger side. We actually haven't used the toilet yet. We recently purchased it from a private seller.

I am going to try to check the owners manual to see if there is a second valve. However, it appears only one black water and gray water valve on driver side, just behind the cab of the vehicle.

[Travelin' Texans]

There's a couple of the recommendations I'd skip!
The use of a snake in a rv with a plastic tank, I'd suggest a length of old water hose with or without water pressure rather than the snake, you won't poke a hole in the tank use the hose.
The other is the use of Rid X, it won't hurt to use it, but it suggest using every 30 days as it takes that long to digest/breakdown the waste. Although the campground where you drain the tank will appreciate the treatment.
Rv waste tanks are "holding" tanks not septic systems.
No more than 2 ply septic safe tissue & plenty of water. And don't rely on your tank sensors for any accurate tank levels, most likely when you get that tank drai Ed it'll still read full.

[Judge]

Originally Posted by Travelin' Texans

There's a couple of the recommendations I'd skip!
The use of a snake in a rv with a plastic tank, I'd suggest a length of old water hose with or without water pressure rather than the snake, you won't poke a hole in the tank use the hose.
The other is the use of Rid X, it won't hurt to use it, but it suggest using every 30 days as it takes that long to digest/breakdown the waste. Although the campground where you drain the tank will appreciate the treatment.
Rv waste tanks are "holding" tanks not septic systems.
No more than 2 ply septic safe tissue & plenty of water. And don't rely on your tank sensors for any accurate tank levels, most likely when you get that tank drai Ed it'll still read full.

Unless you’re using a power snake, you’re not going to poke a hole through the tank.

And using RidX every 30 days is worthless unless you only empty the tank every 30 days. If you empty the tank regularly and flush it like most folks do, RidX is not going to do anything.

My suggestion for RidX was a short term attempt at breaking down waste causing damming and as I said he would need to let it sit for a while to take effect.

[EA37TS]

My black tank is 40 gallons.

I use a Save A Drop water gauge attached to the hose connected to the black tank flush.

I turn on the water to the flush and pull the valve to flush the tank. After about two minutes I turn the flush off. Once drain I close the drain valve and reset the gauge to 0. Turn on the flush and fill the take in increments to 20, 25, 30, and 35 gallons. Draining between each. If there is still debris or the water is not crystal clear I repeat the process with the final fill being 37 gallons. After the final drain I use the gauge to put 3.5 to 4 gallons into the black tank.

Yes it takes time but it is worth the time.

I do this process every 4 days when on extended stays or early in the morning on departure day regardless of the tank sensor readings.

[Judge]

Originally Posted by roaddawg

I'll try these suggestions. This is a 2016 Thor Class C, four winds 28Z. Bathroom is on passenger side. We actually haven't used the toilet yet. We recently purchased it from a private seller.

I am going to try to check the owners manual to see if there is a second valve. However, it appears only one black water and gray water valve on driver side, just behind the cab of the vehicle.

If your toilet is on the pasenger side on the Class C, there is a very good chance the black tank is underneath it. If that is the case, look under the coach and see if there is a long section of Black PVC that runs from the passenger side of the coach to the drivers side where the sewer hose connects.

If that is the case, you will have a second valve on the passenger side… and it won’t be in the manual most likely. I had an Outlaw 29H and the manual didn’t mention a second valve…. and the dealer didn’t either.

You will want to open the valve on the drivers side first and then open the valve on the passenger side. You may need to crawl under the coach to see it.

[EA37TS]

I forgot to mention, by using my method I know, beyond a doubt that my black tank sensors read empty from 0 to 6 gallons. 1/3 from 6 to 9 gallons, 2/3 from 9 to 17 gallons and full over 17 gallons.

I also know that the tank flush alone will not clear debris off the sensors. I have to fill the tank and empty to clean the sensors.

[ericmac450]

Originally Posted by EA37TS

I forgot to mention, by using my method I know, beyond a doubt that my black tank sensors read empty from 0 to 6 gallons. 1/3 from 6 to 9 gallons, 2/3 from 9 to 17 gallons and full over 17 gallons.

I also know that the tank flush alone will not clear debris off the sensors. I have to fill the tank and empty to clean the sensors.

Wow, so it reads full at 17 gallons but really you have 23 gallons left of room?

[Judge]

Originally Posted by ericmac450

Wow, so it reads full at 17 gallons but really you have 23 gallons left of room?

They error on the side of caution. I have 40 gallon tanks and they read full at about 25 gallons.

Even on my fresh water tank it reads full at about 45 of 60 gallons.

[EA37TS]

Originally Posted by ericmac450

Wow, so it reads full at 17 gallons but really you have 23 gallons left of room?

That is correct. I would not know that info without the water gauge. I will soon get a second gauge for the fresh water hose so I can gather the same info for the dread and grey tanks. I will not use the same gauge on both sides of the plumbing.

[Chateau_Nomad]

Verifying what Judge stated... If your black tank is at the rear of the passenger side, crawl under and look where the black drain pipe exits the tank. Mine exits rearward, then turns toward the driver side... where it joins with the gray drain pipe. Even though there's a black tank gate valve on the driver side, there may be an additional one closer to the tank.

Look closely where the black tank drain pipe first turns 90°. Ours has a gate valve there, in addition to the one on the driver side near the sewer hose connection point. Our handle faces the rear of the motorhome for the one closest to the tank.

[MJC62]

You did say you have a passenger side toilet?
What hasn't been mentioned yet is the chance of the dreaded poo dam. The coaches with a passenger side toilet have a sewer pipe that drops on a sloped portion of the black tank that remains dry till the tank is almost full. If the operator of the toilet doesn't use sufficient water during use the TP and solids hit the dry slope and stay there, getting hardened into a sludge of sh*t and paper that will back up the toilet. Our ACE in its first life was a rental.
On our first trip out after we purchased the MH the black tank backed up and had to be rammed out with a rubber hose after I initially cleared the blockage with a sewer snake. We suspect the prior renters were never instructed on how to properly flush the toilet or as renters of the RV chances are they didn't really care.
After experiencing a poo dam firsthand, we have added a pre-flush with dish soap to lube the slide then basically follow Judge's procedures. Since the initial poo dam, we have not had any other issues.
As has been said, the extra water involved using a curb side toilet does not lend itself well to extended boon docking trips.

[roaddawg]

THANK YOU one and all!!!!!

I went back out to the RV this morning, before checking the site, and noticed there was still water in the bowl. I tried running water from the bathroom sink and that resulted in bubbles and water rising in the toilet bowl. Frustrated, I came back into the house and checked here.

I went back outside after reading the last few comments and crawled underneath on the passenger side. Lo and behold, tucked up high and against the side of the RV, was another valve....in the closed position. I opened it and immediately heard a whoosh of running water. I went back into the bathroom and ran the toilet and sink and noticed that the water in the pipe began to rise after about a minute.

I pulled up to the sewer connection to dump the tank, after first letting the gray water tank fill about 1/3 of the way. Double checked to make sure the passenger side valve was open, hooked up the hose, opened the valve and a few gallons of water poured through.

I went into the bathroom and turned on the faucet at the sink and observed bubbles and water rising into the toilet bowl. AAAAArrrrgghhhhhh!!!

Went back outside and confirmed that the passenger side valve was open. Then proceeded to check that the one at the connection was open. OOOOhhhhhhh....I had opened the gray water valve. I shut that off, opened the black water tank, and VOILA! All sorts of water rushing from the tank.

I checked inside and sure enough, the bowl was clear and flushing and running the sink resulted in the water flowing unobstructed into the tank. So, thank you one and all, for your comments and suggestions. As a first time MH owner, user, this is still a learning curve. I read the Thor Resource manuals, watched videos (there and youtube) and still manage to screw up!

So, I'm sure there are more questions and queries to follow, but for now, I am so "relieved" to have rectified the problem. Now to just get those sensors to work....

[Chateau_Nomad]

On those sensors... you can flush $100 worth of "specialty chemicals" into your black tank... some folks try to treat it like a home septic system, which IT ISN'T! It's nothing more than a temporary holding tank... no amount of "bacteriological" treatment will ever have time to work... you will wind up donating those chemicals to the campground sewer system.

If your sensors currently aren't working, try this. Flush and drain your black tank VERY well with water. Pour in about 2 cups of any liquid laundry detergent, followed by a cup of liquid Calgon. Then... VERY important! Flush 5 or 6 gallons of water into the tank. On your first treatment, maybe even travel with a half full tank.

Now you're ready to camp. Use the toilet normally... but BE SURE to flush PLENTY of water during use. Yes... your tank will fill a little quicker... but the best thing you can do is DRIVE YOUR MH with lots of "stuff" in your tank... especially with the detergent sloshing around.

Forget trying ice cubes, etc... they melt too fast. Do continue using the detergent mix and LOTS OF WATER, and your sensors will "magically" eventually start working again! When they start working again, cut the detergent/Calgon mix down to one cup each. But continue making sure you use plenty of water.

Always try to travel with a "slosh mix" in the tank. If you travel with empty tanks, BE CERTAIN that black tank is THOROUGHLY flushed... and has the detergent mix in there!

P.S. I don't measure exactly... just pour in about a cup or so... it's not rocket science.

[ducksface]

Tide laundry pods.

Clean, simple, drop in, no measuring.
Work as well as any specialty stuff I've tried. It was an ass-pain measuring out Happy Camper.
I haven't tried an off brand pod yet. I'm sure they work just as well.

[Lt Keefer]

I would suggest you forget about the sensors and learn how long you can camp before the tanks fill up with normal use.