Black Water Smell Under Sinks

**Longshhm** · 10-04-2020, 07:31 AM

Update, since there was interest in what we find:
With the help of Grand Design customer service, we got an appointment with another dealer to get the problem looked at, along with another issue that our original dealer never corrected. It goes in on 10/20/2020. In the interim, it has now begun the dreaded "burping" when it reaches about 2/3 full. Looking more and more like a vent and/or entry pipe issue. We will see what the dealer finds and post another update. NOTE: still have not heard back from the original dealer; apparently, customer service isn't even on their radar.

**AWA315RLTS** · 10-19-2021, 08:19 PM

I too am currently experiencing an odor of sewage. As I have a 315RLTS i have a second small closet. The odor is coming up inside the drawers of the built in dresser in the bedroom and also through the converter ribs in the kitchen. These drawers sit above the hot water tank. I was surprised to notice in this compartment is what looks like an "In-line vent". Why would there be an in-line vent next to the water heater and could swapping this out remove the odor (this works for underneath the sinks)? Also the size of this vent appears to be larger than the ones under the sinks. Is this one also a 1 1/2" or this a 2"? I'm reticent to take this off without having a replacement ready to go.

**Mr. Goodwrench** · 10-20-2021, 08:35 PM

Originally Posted by Longshhm

Thank you all for your input and suggestions. Further usage shows that the smells occur immediately after flushing, but then dissipates within a half hour or so. I can find no evidence of leaking, although, admittedly, I've not dropped the coroplast to look at the insulation. I've been up top and removed the vent cap - no obstruction noted there, but also very little smell coming from the vent pipe. At this point, I'm inclined to think that the vent pipe has broken loose from the tank. Got several calls in to my dealer (who still hasn't any of them 3 days later) and an e-mail sent to Grand Design (still waiting on their response, too). I'll be sure to post whatever I find.

Mike

Mike, if you haven't already found the problem, take the removable wall in the basement out and crawl back in and you can see the black tank pipes where then go through the floor. Both black and grey tank vents are tied together and are visible as well as the slip connection to the black tank. We have the same trailer as yours and had odor problems also. A good black tank rinse and dump cleared up our problem but seeing the plumbing up close gave me some things to check. Good luck and please report back your findings.