Holding tank odor :-(

Blkbart · 07-18-2020, 10:52 AM

Hello all,
I have a 2003 Itasca Horizon 34HD, When I begin to drive the coach after camping, the odor/stench from the holding tank is horrible. It has been doing this for some time now. There are no signs of leaks, thinking it must be vent issues? Please let me know if you have had similar issues and your solutions. Much appreciated...
Thanks,
Bart

Morich · 07-18-2020, 11:36 AM

Many have had an odor problem of this sort but the details are hard to pin down at times. Are you able to say if it is the really strong odor from black water but maybe has the smell of your treatment? Or is it more likely the grey tank smell?
Reason for asking is that both have different things that are likely. For the black tank smell, make sure the toilet is adjusted correctly to leave water in the stool after the valve closes as that it the "seal" for fumes.
If it is the grey tank smell, it may be there is a problem with the air gap gizmo not sealing well. If the airgap is stuck, it can go two ways. When water runs down the sink drain it can suck the water that is supposed to stay in the trap as a seal , down the drain leaving the pipe open to let fumes in. It looks like you have two, so a check of the sink and vanity for water staying in the trap can let you check them. But the airgap can also stick open and let the fumes come out of it directly as it is often just a simple flap of plastic type stuff. Finding them nay be hard but look up where a pipe disappears bhin/under the vanity sink. But they are also sometimes in the wall!
Other causes are always possible but I would give these a first look.
Item 9 on this drawing:

Wyatt · 07-18-2020, 01:27 PM

Quote:

Originally Posted by Blkbart

Hello all,
I have a 2003 Itasca Horizon 34HD, When I begin to drive the coach after camping, the odor/stench from the holding tank is horrible. It has been doing this for some time now. There are no signs of leaks, thinking it must be vent issues? Please let me know if you have had similar issues and your solutions. Much appreciated...
Thanks,
Bart

Only time that has happened to us, is when I’m forced to leave a campsite with an empty black tank, and not enough time to thoroughly rinse it, add more water to cover the bottom, and add treatment chemicals.

Blkbart · 07-18-2020, 02:59 PM

The gray tank is not the issue although I appreciate the suggestions. I’m thinking the black tank issue may very well be the heading out empty issue, going to give it a try with the tank filled minimally with several gallons and the chemicals added. I’ll let you guys know.
Thanks SO MUCH!
Bart

Morich · 07-18-2020, 05:33 PM

Better if it is the black tank as getting to some of the air gaps that are in the wall can get ugly! We kind of have a program of adding treatment and water as soon as possible after dumping as a way to let the stronger treatment work on anything that might be hanging around in the tank as well as giving us the option to go back to the bathroom while on the road.
But we once got a cap off a ball point some way stuck in the stool so that the little slide did not close and that DOES make a smell when you open the door! How does a pen cap get from the front seat where used to the stool in back? Just gremlins I guess!

Topsail · 07-18-2020, 06:53 PM

Quote:

Originally Posted by Morich

Better if it is the black tank as getting to some of the air gaps that are in the wall can get ugly! We kind of have a program of adding treatment and water as soon as possible after dumping as a way to let the stronger treatment work on anything that might be hanging around in the tank as well as giving us the option to go back to the bathroom while on the road.
But we once got a cap off a ball point some way stuck in the stool so that the little slide did not close and that DOES make a smell when you open the door! How does a pen cap get from the front seat where used to the stool in back? Just gremlins I guess!

Op it does sound like it needs water and your favorite treatment. I have rinsed quite a bit and generally don't have trouble.

Those gremlins can be a pain and hard to get rid of!

Jbuntin · 07-26-2020, 06:03 PM

My 2005 Voyage had a problem like that. It was resolved by clearing the rooftop vents, which had been blocked by mud dauber nests.

taz1357 · 07-26-2020, 08:53 PM

Please check your batteries if you have lead acid batteries. I thought I had a problem with my black tank and it was odor coming from bad batteries. I didn't keep them up properly and have since learned.

They are easily checked. Good luck!

If they are not the problem, put one of those winged aerators on the top of your back tank vent on the roof. It helps a great deal!

DNC · 07-26-2020, 08:56 PM

The P.O. Box section of the August 2020 Motor Home magazine covers this topic quite well. It seems that most smells emanating from the holding tank(s) are vent problems. Either the vent was plugged or had come unhooked from the top of the tank. One person that wrote in had purchased a Camco Cyclone sewer vent to extend the vent and help vent more air when moving down the road. One person stated that "It seems that a strong crosswind, or opening a cab window when driving, causes negative air pressure in the coach, which draws gases past the sink traps and stinks up the coach". I guess this could also draw gases from the blackwater tank if the seal is a little worn.

mcgillar000 · 07-26-2020, 10:47 PM

Had the same issue several months after replacing the commode with a new one. After removing the new commode, found black water between the top & bottom sections of commode. Not seeing a way to drain the water, having nothing loose, I decided to separate the two halves. The screws holding them together were loose. After separating and cleaning both halves, reinstall both halves with silicon on both sides of the seal. Haven't had a problem since with odor.

BlueGekko · 07-27-2020, 04:28 AM

Had a similar black tank problem two years ago just after picking up a new class C from Camping World. Poured a lot of neutralizer down the toilet but it didn’t help. Odor got so bad one morning at 2:00 a.m. in northern Newfoundland (maiden voyage with friends) we couldn’t sleep. Found the odor strongest near the coach door. Opened the hatch over the batteries and the odor was overpowering. Popped the tops on the battery cells and found they were all dry. Despite being checked off on the delivery pre inspection check list at CW, the batteries were toast but the system was trying to charge them from the moment we pulled off the CW lot. Odor dissipated nearly as soon as I hit the disconnect switch. Finding replacement batteries in northern Newfoundland is a whole ‘nother story. Newfoundlanders are very nice people.

Paul038 · 07-27-2020, 07:50 AM

Before we leave a campground we make sure to put water down all drains to fil up the P traps. Then plug and add a little water for a good seal. Also, and 1" of water in the toilet. If we don't we will get a smell.

GPanek · 07-27-2020, 09:42 AM

We found the same problem of odor after pulling out of our site and headed toward the RV dump. It was a loose cheater valve under the bathroom commode. See this video which explains it.

https://www.youtube.com/watch?v=4nj8...index=43&t=85s

HappiHenri · 07-27-2020, 12:05 PM

Just use Happy Camper. Works great. No smell - but then I add immediately after emptying tanks, and a bit more as we fill them up.

Also make sure that you are emptying your black tank correctly. If hooked up to full hookup site never leave the black tank valve open. You want the black tank to mostly fill - with lots of liquids in it - before emptying. This helps to ensure that most of the solids flow out while mostly suspended in the liquid.

Also - be sure to flush you tank well when emptying. We have a 5 gal pail which we fill and dump down the toilet while dumping the black tank. This massive flush of water helps clean out the tank - may have to do several times. Which we know because we have a clear drain hose adapter right at the beginning of our sewer hose - so we can see exactly what is coming out of our tank. Sounds gross but we will keep flushing until water runs clear.

gurroz · 07-27-2020, 06:04 PM

If I had your problem I think I would install the Camco Cyclone on my vent pipe. People that use them say it solved their problem. I think it cost about $15.00 so not much to loose. Maybe someone on here has tried one and can offer a first hand opinion.

wyocamper · 07-27-2020, 08:25 PM

We had an issue with black tank odor on a couple trips last year, but only after staying in camp grounds and not after boondocking. Turned out it was because I was dumping just before pulling out, and only putting a few gallons of water in the black tank. The odor was horrendous. Now after I dump I rinse the tank using the black tank flush valve until the water comes out clean, then close the drain and run the water until the 1/3 full light starts to flicker. Drop in a packet and we're good to go till the next dump.

TL/DR version: put lots more water in your black tank.