R29 CB Waste Vent

[Scuba Too]

My 2017 R29 CB is about 3.5 years old. Aside from an initial episode of foul air (literally would bring tears to your eyes) I learned how to maintain a seawater flushed toilet (with Odorlos being a big help) and it's been going well up until recently. Now after flushing odor seeps into the head, but not from the outside. I accessed the tank and flushing does not cause any odors in this area so the fittings are tight. There is some venting that occurs on the outside vent but there's also some build up on the vent so there may be some partial blockage. I suspect that some pressure builds up during flushing and the odor seeps in through the connection to the head since the waste tank area doesn't have any odors. So with this in mind:

- What's the best way to check the connection to the head?
- Could there be a seal in the head that's causing a problem?
- Can the built-in screens on the waste vent be removed from the outside of the boat? The idea would be then to snake the vent hose.
- If the vent outlet has to access from the inside, what's the best way to access it? I can see it from the cubby but there's no working room from that approach.
- I noticed that there's caulking around the hoses to the tank. What is this caulking and do you recommend replacing it if the hose is removed?

Thanks!

 

[Matty]

Yes, not a pleasant smell. We accused a few on board of having issues before we figured out the source. Type “waste vent” in search bar on this page and you will see lots of discussion.

 

[Scuba Too]

Thanks Matty,
I did go through the posts, which narrowed things down and helped me craft the questions. For example based on what I've read adding a charcoal filter probably wouldn't help as one poster found.
Eric

 

[Toki]

As you probably saw in my post on the subject, the symptoms on my R27 were the same as yours and it turned out to be a clogged vent line. Easy fix on the R27 because of good access to that vent line, not sure about your R29. But I think you're on the right track by figuring out a way to inspect/clear that vent line.

 

[Scuba Too]

Hi Toki,
I saw your earlier post and it was very helpful! Hopefully there'll be a good way to access the waste hull vent on my boat.
Eric

 

[Toki]

Where is the waste tank on the R29? On the R27 it's at the stern, and access to that vent fitting at the tank is beneath the transom bench. Pretty easy to pop that vent line off the tank fitting and clear it out.

 

[Hydraulicjump]

Regrettably, getting to the waste vent is less than fun on the 29CB. You will find access to it through a monkey fur covered panel at the forward end of the quarterberth. You can detach the vent hose there (don't blow on it like some earlier post!). This is also a good place to cut in a charcoal filter if you want to.

Have you ruled out foul smells coming though the joker valve on the toilet? Quickest way to check is to see if the toilet holds water. You can see earlier discussions about that unpleasant job.

 

[BeaconBluff]

There is access to the waste line under the bow berth. I was able to install a vent filter there and it works just fine.

Rodney
Rx Isle R29S

 

[Scuba Too]

Update to this problem. It turns out to have been the raw water side of the head was causing the odor. I did pull the vent hose and there was no particularly strong smell nor blockage. I also did the vinegar flush and soak in case there was calcification on the joker valve (which I didn't think was the case since there wasn't a smell from the tank but it certainly couldn't hurt). I then added water to the bowl using the switch and realized that it was coming from the intake side - and it was bad! I thought I'd just flush it a few times when getting on the boat but it didn't help a lot. I then tried the vinegar flush through the intake and that worked great! Weeks later and still no strong odor. Nice thing is that I didn't have to pull the hose on the intake - the strainer filled to the brim has sufficient volume for a flush with a little left over so that the pump doesn't run dry. I added vinegar and water (10-20% vinegar) and flushed until I smelled vinegar in the head and then a couple more times just to be sure. I then let it soak for a few days and success! As to why the intake was so bad after no problem for over 2 years it could have been that we had a really persistent red tide in California which lasted months (really unusual) and all those critters died in the hose. In any event back to being a happy skipper. And I'll be doing the vinegar flush as regular maintenance going forward.

Just to note I used Odorlos (I'm generous with the pour), regular pump outs, no vent filter and now vinegar washes to keep my head odor free.

 

[Kathy H]

Update to this problem. It turns out to have been the raw water side of the head was causing the odor. I did pull the vent hose and there was no particularly strong smell nor blockage. I also did the vinegar flush and soak in case there was calcification on the joker valve (which I didn't think was the case since there wasn't a smell from the tank but it certainly couldn't hurt). I then added water to the bowl using the switch and realized that it was coming from the intake side - and it was bad! I thought I'd just flush it a few times when getting on the boat but it didn't help a lot. I then tried the vinegar flush through the intake and that worked great! Weeks later and still no strong odor. Nice thing is that I didn't have to pull the hose on the intake - the strainer filled to the brim has sufficient volume for a flush with a little left over so that the pump doesn't run dry. I added vinegar and water (10-20% vinegar) and flushed until I smelled vinegar in the head and then a couple more times just to be sure. I then let it soak for a few days and success! As to why the intake was so bad after no problem for over 2 years it could have been that we had a really persistent red tide in California which lasted months (really unusual) and all those critters died in the hose. In any event back to being a happy skipper. And I'll be doing the vinegar flush as regular maintenance going forward.

Just to note I used Odorlos (I'm generous with the pour), regular pump outs, no vent filter and now vinegar washes to keep my head odor free.

We had the same problem in our 2016 C30, a horrible odor after a couple days of no use. The odor would clear after three flushes and with use. We would use 4 oz of Odorlos after each pump out. We followed your advice using 20% vinegar with fresh water in the raw water strainer, flushed it through the line to the toilet, and let it sit for a couple days. The odor is gone. Thank you!

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