Black tank odor

Oh, well. if you are not using it, no...just put some water in and walk away. (the water will enure nothing gets dried onto anything) I might have mis-read your note and interpreted it to suggest you were going to be using the unit.

To recap..no, if it not being used...no need need to dump. But when you do...be generous with your time and water.



Gary Haupt

old guy wrote:
dumping once a week? is it necessary? I think so. isn't it obvious to you now since you had such a terrible smell in the MH already? when it comes to the tanks, black or grey, take care of them or you will be so sorry. I forgot to close the valve on the black tank once in Yuma, had to do the dance to get it flowing again. Oh yes, and buy some deodorant for the MH, it will probably smell like black tank for a while.

The reason I ask about the once a week is we won't be in it near that often. In the Lance we dumped the tanks when leaving the campground, through in a pouch of toilet powder (forget the brand name) and forgot about it until the next outing. It's been 100% trouble free. So if we aren't using it, what needs to be dumped?

dumping once a week? is it necessary? I think so. isn't it obvious to you now since you had such a terrible smell in the MH already? when it comes to the tanks, black or grey, take care of them or you will be so sorry. I forgot to close the valve on the black tank once in Yuma, had to do the dance to get it flowing again. Oh yes, and buy some deodorant for the MH, it will probably smell like black tank for a while.

garyhaupt wrote:
When you are dumping today....dump and rinse 3 or 4 times. If you have a rinse inlet, cool..if you don't you may have to drag a hose inside and poke it down the toilet. Don't be worried overly about the sensor. They are all crap, anyway. You just to make sure that you have gotten any build-up out. Sure..some Simple Green now, before you go to the dump place. Let is slosh around some.

After dumping till you figure you have it...put in a bunch of water...5 or 6 gallons. Throw in your Simple Green and let it be.

The vacuum created by open windows will draw smell into the cab. You won't get any smell till after a week. So...every 5 days, dump.


Gary Haupt

I plan on dumping in my cleanout for the house. There's nowhere nearby that I can dump so it's the option I have. But the benefit is, no rushing and can flush as much as needed.

Do I really need to dump that often? I never did in the Lance. We aren't full timing by any means. Most we will do (I say that now) is weekend trips to state parks/off-road parks.

When you are dumping today....dump and rinse 3 or 4 times. If you have a rinse inlet, cool..if you don't you may have to drag a hose inside and poke it down the toilet. Don't be worried overly about the sensor. They are all crap, anyway. You just to make sure that you have gotten any build-up out. Sure..some Simple Green now, before you go to the dump place. Let is slosh around some.

After dumping till you figure you have it...put in a bunch of water...5 or 6 gallons. Throw in your Simple Green and let it be.

The vacuum created by open windows will draw smell into the cab. You won't get any smell till after a week. So...every 5 days, dump.


Gary Haupt

IAMICHABOD wrote:
The smell may not be coming from your Black tank,it may be the gray tank.


I would check and replace the air admittance valves
located near your sinks,they are cheap and can be found at most big box stores like Home Depot and Lowes as well as smaller hardware stores.

If they fail they will let the smell from the grey tanks in and believe me they can smell just as bad as the black tank if not worse.


Changed mine out and the smell was gone!

Anyway to tell if they're bad? I'm hoping that's it. I don't have a very strong stomach when it comes to odors.

Since there is no telling how long those tanks have had fluid in them I'm hoping it just needs a good flushing. This afternoon I plan on dumping the tanks and throwing some simple green in there for a little bit. I'll also bust out my spinny black tank cleaner thingy just to be sure the sensors and all are cleaned off.

Someone said that leaving the vents open while driving can make the small worse, what's the reason for that? I had the fart fan going and the vent open to try and alleviate the smell.

If the MH's been sitting for weeks/months with waste water in it, especially in heat, I would expect horrible smells.

Lots of varied and opposing views will come from this question. I used lots of different chemicals as I did the learning curve. What I found was...pour in whatever chemical I was using, in a week..oh my God...don't use any chemicals, make sure I have 5-7 gallons of water in the tank after flushing...in a week..oh My God.

Bottom line is...if you are moving the rig, after a week, it's going to smell. You will get the gases as the Rv goes down the road, windows open, etc...draws the gases/smell into the cab. And yes, if you are using the RV plumbing you will have water in the P traps anyway. Don't wait till the tanks are full..just do a dump and clean once a week. Takes care of all of that.



Gary Haupt

If you have the ceiling vents open and vent fan going as you drive down the road... whatever problems you have with smells coming up from empty P traps or tank vents are going to be compounded.

Make sure you have water in the sink and tub/shower drains. While you dump, water can be sucked out of those P traps... so run some water in them.

5 weeks ago I switched to a product I found at Ace hardware... DRAINBO (Marine and RV treatment and cleaner).I'm really happy with it. Up to then I had tried RvDigestIt for about a year. And before that I was using TST Orange Tank Cleaner from Camping World.

We have a truck camper but we full time in a Class A. The Class A stays in one spot for very long periods of time. The last time we rolled these wheels was in October 2011. (The truck camper is used as a guest house and it's our "travel vehicle".)

The smell may not be coming from your Black tank,it may be the gray tank.


I would check and replace the air admittance valves
located near your sinks,they are cheap and can be found at most big box stores like Home Depot and Lowes as well as smaller hardware stores.

If they fail they will let the smell from the grey tanks in and believe me they can smell just as bad as the black tank if not worse.


Changed mine out and the smell was gone!