Dynamax Isata 5 Black Holding Tank Smell!

[rlind]

Hi everyone,
I sure cold use some help/suggestions with my 2020 Isata 5 30fw. I am currently on my first major summer trip...4+ months. There is a lot to like about this unit. It sure drive nicely, excellent layout, great power and many quality features. I have owned 8 motor homes over many years...A's, C's, gas, diesel, Winnebago, Tiffin, etc. I have never experienced problems with black holding tank odor until now. The odor is SIGNIFICANT and lasting! I have to apologize for the odor in advance to people that want to look at it. I have tired everything to include doubling up on the recommended chemicals, trying different chemicals, dumping more frequently, flushing the tank regularity, no exhaust fan, lid down, etc. Is anyone else having a similar experience? Is it a design flaw? I asked Greg Tinsman to look at it when I was at the factory at the beginning of our summer trip. He said the roof vent looked okay.
Thank you for your assistance,
R. Lind

[milkman55]

We had similar issues when we got our 30FW back in March. Here is what we did that has been successful.

Google GEO Method for Black Tank.

When we have an empty tank, we fill the bowl with water, the add one capful of Calgon water softener, a healthy dose of Dawn dishwashing liquid and a scoop of Happy Camper powder.

The Calgon makes the water “slick” and keeps stuff from sticking to the sides that creates the smell. The Dawn also makes it slick and helps with the smell. The Happy Camper powder is a bio product that dissolves everything in the tank and when you dump, you would be amazed as it’s all liquified.

We have been in Ruidoso four days and I prepped my tank as shown above. Zero odor and have yet to even need to empty the black tank.

Also very important you use the black tank flush when you do dump and get a clear elbow for your sewer hose so you can see when the water gets clear.

[bclemens]

Originally Posted by rlind

Hi everyone,
I sure cold use some help/suggestions with my 2020 Isata 5 30fw. I am currently on my first major summer trip...4+ months. There is a lot to like about this unit. It sure drive nicely, excellent layout, great power and many quality features. I have owned 8 motor homes over many years...A's, C's, gas, diesel, Winnebago, Tiffin, etc. I have never experienced problems with black holding tank odor until now. The odor is SIGNIFICANT and lasting! I have to apologize for the odor in advance to people that want to look at it. I have tired everything to include doubling up on the recommended chemicals, trying different chemicals, dumping more frequently, flushing the tank regularity, no exhaust fan, lid down, etc. Is anyone else having a similar experience? Is it a design flaw? I asked Greg Tinsman to look at it when I was at the factory at the beginning of our summer trip. He said the roof vent looked okay.
Thank you for your assistance,
R. Lind

In addition to the above (which is very good advice), make sure the exhaust fans are on "exhaust" we have gotten a few batches in that are IN and OUT.

Make sure all the P-traps have water, some times when driving around water can slosh out of the P-traps.

We use the 360 siphon vent...so that should be creating positive pressure out of the vent.

lastly, maybe double check that you can get proper gallon of water in the black tank. There were some instances where the vent was put in too far and if that is the case, then it may not be venting properly.

[TrailWayz]

Originally Posted by bclemens

lastly, maybe double check that you can get proper gallon of water in the black tank. There were some instances where the vent was put in too far and if that is the case, then it may not be venting properly.

Can you explain this? What do you mean by proper gallon of water?

We've been having some black tank odor problems as well. I've been flushing the black tank almost every day and it has been helping to mitigate the odor some but it was almost unbearable early on with this current trip. I'll give the Dawn and Calgon a try with the RV Digest-It we've been using, to see if that helps.

What is the remedy if the vent was put in too far?

Milkman, you mention a healthy dose of Dawn, what is considered a healthy amount in approximate ounces? 4? 8 oz? I imagine you don't want it sudsing up when you flush the tank?

Thanks.

[bclemens]

If the black tank is 46 gallons...make sure you get somewhere close to that in the tank before things start to back up. If the vent hits the water level, then it may vent somewhere else when water is introduced.

Personally I don't thing sudsing is bad. The more of that you get on the walls and ceiling of the tank, the less stuff sticks.

[TrailWayz]

Originally Posted by bclemens

If the black tank is 46 gallons...make sure you get somewhere close to that in the tank before things start to back up. If the vent hits the water level, then it may vent somewhere else when water is introduced.

Forgive me for not totally understanding. So the problem with the vent being pushed in too far will usually only occur as the tank is nearing full? Otherwise it should be venting properly?

If that's correct, then I am not getting close to filling the tank at the moment as I dumping and flushing almost daily.

Gotcha on the sudsing I'll start conservative though - maybe +/-6 ounces of Dawn.

Thanks.

[bclemens]

In theory yes. It should only happen when the water level hits the vent. If you have not felt like you were short on tank space, then you are likely fine.

[TrailWayz]

Thanks, will try the Dawn and Calgon. See if that helps.

[milkman55]

I used about 3 tbsp of Dawn with one cap of liquid Calgon.

You don’t want to be dumping your tank daily as they keeps the sides of the tank dry and that’s probably where your odor problem is coming from. I don’t dump mine until it’s either full or we are leaving a campground and driving a good amount. Even overnight stops, I don’t dump the black tank.
All the suds splashing on the walls when you drive is a good thing.

[LandKKnight]

Originally Posted by milkman55

I used about 3 tbsp of Dawn with one cap of liquid Calgon.

You don’t want to be dumping your tank daily as they keeps the sides of the tank dry and that’s probably where your odor problem is coming from. I don’t dump mine until it’s either full or we are leaving a campground and driving a good amount. Even overnight stops, I don’t dump the black tank.
All the suds splashing on the walls when you drive is a good thing.

This^^^
I have a 2018 30 FW and have used the Calgon/Dawn method all along, (well, after I figured out why we were getting a poop pyramid and fixed it, another loooong, thread, kinda gross, you can search it if you're interested). I also wash the dishes with a container to catch all suds and pour the whole thing into the toilet to increase the sudsing action. We never have odor.

[Larry-NC]

Originally Posted by LandKKnight

This^^^
I have a 2018 30 FW and have used the Calgon/Dawn method all along, (well, after I figured out why we were getting a poop pyramid and fixed it, another loooong, thread, kinda gross, you can search it if you're interested). I also wash the dishes with a container to catch all suds and pour the whole thing into the toilet to increase the sudsing action. We never have odor.

Here's the TL;DR version.

After you empty the black tank, immediately put a couple of gallons of water back into it. When you put "waste product" into the tank it will hit the water and not stick to the bottom.

[rlind]

Thank you everyone very much for your suggestions and recommendations regarding my black tank odor. I have already begun to implement many of them recognizing it will take several dump cycles to see if that solves my problem...need some good sloshing around time. It sounds like these suggestions may also help with my Gray Tank gauge reading 1/3 or 2/3 right after I dump...just can trust it. Best to all.
rlind

[sconnors11]

Putting ice in the black tank just before driving helps scrub the tank as you drive... It'll help accelerate the demise of the Poop Pyramid

[Larry-NC]

Originally Posted by sconnors11

Putting ice in the black tank just before driving helps scrub the tank as you drive... It'll help accelerate the demise of the Poop Pyramid

That myth has been thoroughly debunked.There are several YouTube videos that show how ineffective it is.

Here is one

.

[Pspoon]

Part of the odor issue is the exhaust fan. It moves to much air for a small room and pulls air out of the black tank when you flush. I leave the bathroom window open, the fan on low and the smell has stopped. I do the Calgon, dish soap, happy camper also. I’m considering cutting an inch off the bottom of the bathroom door to increase airflow when it is to cold to keep the window open.

[bclemens]

Originally Posted by Pspoon

Part of the odor issue is the exhaust fan. It moves to much air for a small room and pulls air out of the black tank when you flush. I leave the bathroom window open, the fan on low and the smell has stopped. I do the Calgon, dish soap, happy camper also. I’m considering cutting an inch off the bottom of the bathroom door to increase airflow when it is to cold to keep the window open.

Good point. The MaxAir fan is really over-kill for the bathroom as it is really designed as a "whole coach" fan. But I did not love the quality of the normal roof fan. But yes, you need to have it on 10 or 20% power. Not 100%.

[KRedburn]

Just another thought:

If you are traveling camp to camp I usually do not dump tanks every day. Example: stop over in one camp for a couple of days move on to next etc.
Dump when tank is minimum 3/4 full. The movement going down the road sloshes the dawn, calgon water softener (caution: do not use the fabric softener) and desolve it cleaning the sides and top of tank.
Also you should make sure the toilet valve is closing. Some water should remain in the bowl after a flush and not drain off.

Turn your fan down to 20% exhaust.

All that should eliminate your odor issue.

[rlind]

Would this help solve the problem: Ultra-Fab 53-945001 Solar Powered RV Plumbing Vent Cap?

[milkman55]

You have a Siphon 360 vent which is not powered but is designed to maximize venting. Anything powered exposed to the elements is a problem waiting to happen.

The problem with black tanks is people think of them in relation to their home plumbing which always has a water barrier between you and the smell. In the RV, every time you push that toilet flush, you are exposed directly to the black tank and it’s odor. The only way to deal with it is lessen the odor.

Dumping your tank too often and letting the crud dry to the sides of the tank is probably the single biggest cause of odor. Treat the tank with odor additive (I use Happy Camper) and wait until it’s almost full to dump and then rinse multiple times before it dries.

Also, I always close the toilet lid before I flush and never have the bathroom exhaust fan going when you flush as it’s pulling the odor directly from the tank.

I have been on a 16 day camping trip with two people that will end tomorrow and I will have emptied my black tank three times, about every 5 days and odor has not been an issue.

[cbwood]

Are you getting this odor only when you flush, or at other times, too? You mentioned it is long lasting.

My I4 25FW had occasional bad black tank odor when the bathroom was not being used. Eventually found the tank to be leaking. After the repair from hell (another post) that still did not fix it, Greg at Dynamax found that both vent pipes were loose from the top of the tanks. Also I think he resealed the toilet to tank connection.

In my opinion, if the toilet and black vent connections are tight, the only place odor can escape is thru the roof vent. And you shouldn't smell that unless the bathroom fan vent is open, if even then.

Another thought that just occurred to me is the possibility that the waterless trap in the shower drain might allow odor thru, since gray tank vent is connected to black vent? That seems not too likely, though. There are also those same traps in the sinks.