draining tanks; is this normal?

2013 3950; used it a few times and this is occuring

1) black tank drains slowly (+10 minutes) if its indicating 3/4
2) black tank indicator isn't accurate (always shows 1/2 or more even when nothing is coming out of the tank); i've used the tank cleaning system (where you attach the garden hose) but didn't make a difference
3) sewer smell inside coach when draining tanks; when hooked up to the drain with valves open you can smell sewer smell inside the rig

are the rest of you having the above happen?
our last 5th wheel didn't do any of these things so I'm thinking something is incorrect
any input?

Keep your valves closed until you are going to drain your tank(s) even when you are hooked up to the sewer.

ALWAYS leave your black tank closed, unless you are dumping. If you leave it open, solids will build up and you will ruin your tank.
Leave water in the toilet, it forms a vapor seal.
My black tank takes about 2-3 minutes to empty. Then I will go through a 2-3 flush process, for about 60-90 seconds each.
I would say, if yours takes 10 minutes, maybe you valve is not opening all the way, or your sewer pipe angle is wrong. I suggest having your dealer check it


I will leave gray valves open when hooked up for extended periods. If I smell something, I will close them.
It varies from one location to another, as to whether I get smells, or not.

These are great for helping with tank smells. Consider getting one, or more. http://www.campingworld.com/shopping/item/cyclone-sewer-vent/31992


Hope anything here helps, Trace

steiny, I suppose, worst case scenario, you might have a drain line not pitched enough to drain quickly. That might be the cause of the slow black tank drainage issue. We usually wait till it's near full to dump. I also use a special tool that wedges in the toilet bowl to keep the flusher ball open when draining. This allows a lot of air to follow into the tank for a faster flush. I turn on the tank rinser as soon as I pull the drain valve too. Let it run a long time.
The tank level indicators are pretty useless. All of my prior trailers had the same sensors and false readings. You could check for a loose wire on a sensor but the under belly would have to be removed to access them.
About the only time we get any odor is if one of the fantastic fans is running and pulling the odor in. I recently read a thread where an owner went up on the roof and pulled the vent caps off and made sure the vent pipes came all the way up to the roof and sealed any gaps then re-installed the caps. This solved his problem with the odor. Some folks have replaced the vent caps with them turbo devices that look like weather vanes.
Hope you get the problems solved.

thx for the replies; sounds like our 5er has some issue

for context...
we do leave all of the valves shut unless we are dumping
the smell is coming into the 5er while the tanks are being dumped (so smell happening within a short time frame like within a minute)... when not dumping no smell

i'll get in touch with the dealer and get an appt scheduled, thx

interesting item to note,
when we flush the toilet it splashs within the bowl; its like there is pressure within the tank causing air to try to get out

If you are getting a "burp" at the bowl...then you have a vent issue, which could cause all these issues. Either it's clogged or dropped into the tank....

I don't think this is normal for a new rig. However, this happened to us on our last rig after many months of poor flushing habits.It started burping and draining slow. We had build up in our tank. I ran a water hose down the vent and tolet and was able to flush the build up out after many hours. I also put 5 gallons of water in my tank and drove around and still lots of build up came out. If your drain valve is leaking you may have buildup already. I seen other folks with this same problem and drive around worked for them . If you have build up, just drive around with water in the tank.

We had a bad smell with our first flush with our new rig, I installed my extream vent and no smell on the second flush. THey really help.

sewer smell inside coach when draining tanks; when hooked up to the drain with valves open you can smell sewer smell inside the rig

Click to expand...

Sewer smell inside when draining the gray tanks? Are all the valves open at the same time?

steiny93 said:

interesting item to note,
when we flush the toilet it splashes within the bowl; its like there is pressure within the tank causing air to try to get out

Click to expand...

steiny, this is the final indication of the black tank getting full. As kakampers mentioned, you may have a venting problem or a build up in the tank. It's what some of us refer to as the "pile of pucky". The solids build up in the tank and block the pipe that comes down from the toilet. This is usually caused by a slow leak at the drain valve allowing the liquids to escape while the solids and paper remain in the tank. This doesn't take long to happen either.
As mikeandconnie mentioned, try flushing with a hose through the toilet bowl first. You can also remove the vent cap on the roof and try running the hose down that pipe as well just in case the vent is blocked.

danemayer said:

Sewer smell inside when draining the gray tanks? Are all the valves open at the same time?

Click to expand...

we don't have all the valves open at the same time... but if we open the black valve we will get a smell within a couple of minutes... same with the grey valves (either grey 1 or 2) if we open a valve and have it drain for say 10 minutes; we'll get a smell within 5 minutes

we don't leave any of the valves open; we only open them when we are draining

all in all;
the tanks on the 5er drain slowly (+10 minutes for each tank) I'm guessing we have a vent issue
i've made an appointment with the dealer for next monday; i'll report back to this thread after the appt

I was discussing the subject of tank build up with someone in Gillette.

They had a good idea for removing black tank solids. Said they had done it.

Dump about 10-20 lbs of crushed ice in your tank, along with a little water and drive for awhile.

The scrubbing action of the ice loosened the solids in the tank and of course ends up only as water.

Apparently it freed everything up. Trace