Sewer Odor in Pass-through

[Rick G]

We have a 2016 Montana 3711FL (front living room), immediately behind the living room is the kitchen sink and kitchen, then the bathroom, and then the bedroom. When running a box fan in the kitchen in front of the steps leading up to the living room there is strong sewer odor coming into the camper from the step vents under the steps and there is also strong sewer odor in the pass-through compartment; sometimes the odor is even strong enough that it can be smelled in the basement. Does anyone have an idea of why we are experiencing this odor from the front when the black tank and bathroom are in the back?

[DQDick]

If you have a cracked tank, vent pipe issue or slow leak back there the smell could be finding a way along the choroplast until it finds a way into the utility area and from there the area below the stairs is available.

[bad99ram]

Originally Posted by Rick G

We have a 2016 Montana 3711FL (front living room), immediately behind the living room is the kitchen sink and kitchen, then the bathroom, and then the bedroom. When running a box fan in the kitchen in front of the steps leading up to the living room there is strong sewer odor coming into the camper from the step vents under the steps and there is also strong sewer odor in the pass-through compartment; sometimes the odor is even strong enough that it can be smelled in the basement. Does anyone have an idea of why we are experiencing this odor from the front when the black tank and bathroom are in the back?

On one of my units I had a horrible odor. Turned out to be a bad battery, case was bulged out and it was hot.

[Rick G]

I'll check the batteries tomorrow night after work. The other day when I walked under the front by the exterior battery vent, I could smell the odor at that exact point, I thought the smell was coming from the basement compartment. It would be nice if this is the culprit. If not, then this weekend I guess that I'll try removing the pass-through panels and see if I can reach the front holding tank vent. The last resort, I'll remove the choroplast and try to see if the holding tank is leaking. Thanks for the ideas.

[bad99ram]

Following

[Bierp]

Also following. I'm getting an odor in my 2018 3950BR and I did catch a whiff of it in my passthrough as we hooked up tonight. Please let us know what you find.

[Goose]

I had same issue in a 3791RD. Thought it was a sewer issue and even put a water seal in the sewer hose. Order got worse over a couple of days and then I walked by the battery vent and I knew it was the batteries (I have two). The batteries were so hot that the battery box was too hot to touch by hand to get the cover off. I turned battery disconnect off and let cool for about an hour. Both batteries were still too hot to remove with bare hand so I had to use leather glove to remove and replace. I found that the wing nut for the positive terminal on the battery was very loose. I replaced both batteries with AGM type batteries. No issues since.


Goose

[JABURKHOLDER]

Could be the check valve for the black tank flush.

[Rick G]

Originally Posted by Bierp

Also following. I'm getting an odor in my 2018 3950BR and I did catch a whiff of it in my passthrough as we hooked up tonight. Please let us know what you find.

It looks like the batteries may have been the problem. I was finally able to work on it yesterday and after removing the battery cover the terrible smell was almost overwhelming. Anyway, I took the batteries out, one battery was completely dead and no fluid in any of the cells, the other battery, fluid was only visible in one cell and that battery had a charge of about 9.75. Replaced both batteries and 3 new cables because the cable ends had about 1/4" of exposed wire strand at the lugs. Camper has been closed up now for about 24 hours with air-conditioners running and a box fan placed in front of stairway to help move air around. Did a smell test this morning and no odor, the DW checked the camper about 30 minutes ago and said no odor, it smells like a new camper again. Thanks for the help and ideas!

[Golfmedik]

Originally Posted by Rick G

It looks like the batteries may have been the problem. I was finally able to work on it yesterday and after removing the battery cover the terrible smell was almost overwhelming. Anyway, I took the batteries out, one battery was completely dead and no fluid in any of the cells, the other battery, fluid was only visible in one cell and that battery had a charge of about 9.75. Replaced both batteries and 3 new cables because the cable ends had about 1/4" of exposed wire strand at the lugs. Camper has been closed up now for about 24 hours with air-conditioners running and a box fan placed in front of stairway to help move air around. Did a smell test this morning and no odor, the DW checked the camper about 30 minutes ago and said no odor, it smells like a new camper again. Thanks for the help and ideas!

Glad you found it. We love it when someone solves a problem.

[Lenny K]

Make sure you check the water level on a schedule otherwise you'll have the same problem again. Also make sure your batteries are 100% charged between trips otherwise it won't take long to kill them.

[Rick G]

Thanks for the advice on keeping the cells filled and batteries full of charge. Last year we had a 50 amp outlet installed on the exterior of our garage so the camper is plugged in either at home or in campgrounds from April thru November. What is the standard lifetime expectancy of a deep cycle Group 27 battery? Our warranty paperwork said they were only guaranteed for 1-year, but they lasted from August 2015 until now (August 2018).

[DQDick]

I've always figured I could get three years out of a properly maintained battery. After that I checked them closely. AGM batteries seem to last much longer and don't need much in the way of maintenance so I use them exclusively now.

[Rick G]

Dang, live and learn! I should have done some research before buying those high priced flooded batteries. Hopefully, I'll get more than 3 years of use out of these especially since I'll be keeping an eye on the cells. Thanks for your help.

[BubbaLynn]

Originally Posted by Rick G

Dang, live and learn! I should have done some research before buying those high priced flooded batteries. Hopefully, I'll get more than 3 years of use out of these especially since I'll be keeping an eye on the cells. Thanks for your help.

Well so far I've gotten over eight years on my properly maintained - four six volt - purchased from costco - golf cart - deep cycle - flooded cell batteries...so there is always hope.
Keep a close eye on water levels (use only distilled water to refill) and buy a hydrometer to check for dead cells.

[Lenny K]

I got 7 years out of my 4 x 6volt Interstate before they started using too much water and not holding the charge as long as I thought they should of.
I am now using 4 x 6volt Trojans for the past 4 years and they're going strong. I will easily get 7 years out of them also.

[jeffba]

Originally Posted by Lenny K

I got 7 years out of my 4 x 6volt Interstate before they started using too much water and not holding the charge as long as I thought they should of.
I am now using 4 x 6volt Trojans for the past 4 years and they're going strong. I will easily get 7 years out of them also.

Are the Trojans flooded or AGM?

Thanks

[Lenny K]

The Trojans are flooded.

[Bierp]

Originally Posted by Lenny K

The Trojans are flooded.

You can’t really expect me to read that with a straight face...

[Otto02]

Has anyone else tried these? They are battery fill kids which make filling the batteries much easier. I have to say, I really like these suggestions and ideas.


https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1