H460 Under Sink Odor

[Brigadoon460]

Hello, I have a 2001 H460 and have been dealing with an unpleasant odor that comes from underneath the sink and garbage area. I have cleaned everything out and inspected for leaks but have not found anything. I smells like it could be coming from the holding tank vent but the vent is not anywhere near this area of the boat. Has anyone else had this problem or suggestions?

As always your advice is greatly appreciated.

 

[Don Lucas]

Have you tried cleaning the sink drain hose? Also I don't know about the 460 but on my 410 there is a shower sump boat under the sole in the gallery and it has to be cleaned once in a while.

 

[Jackdaw]

Well, sewage has a very district odor. So does rotting food. Or a dead mouse.

 

[Peggie Hall HeadMistress]

I suspect you have trapped water under the sole. Left to sit and stagnate, it can turn into primordial soup that can make a whole boat smell like a swamp or even a sewer. Sewage odor isn't anywhere near as unique as you might think.

The water can come from a variety of sources, including condensation and humidity. Some Hunter models have a "grid" between the sole and the hull or any liner that SHOULD have limber holes in the members to allow that area to drain, but a lot are either omitted or plugged. Access to clean that area out is limited, which makes the usual approaches to bilge cleaning only marginally successful at best. Enough bleach will knock the odor down, but it just comes back.

If it were my boat--in fact, what I did to my own boat--I'd install a new hatch (more than one if necessary) in the galley sole that provides the access you need to clean out that area and keep it clean.

Boat owners, especially first timers, are horrified by the THOUGHT of cutting even a tiny hole in their boats that the builder didn't put there, much less a whole new hatch! But there's nothing sacrosanct about the number of hatches a boat builder does or doesn't install in any boat...those decisions--and most others too--are cost driven, and hatches are more expensive that uninterrupted sole. But the access that additional hatches provide are worth at least 5x what they cost an owner who installs them. And IMO, that's the only way you're gonna get rid of the odor and prevent it from coming back.

Especially if it IS a dead mouse!

 

[Benny17441]

Dead mouse was the first thing that came to mind but if it is the smell will pass within a few days. It is very hard to describe smells online and it is even harder to describe their intensity. If it smells like rotten eggs take a look at the anode in the water heater. I don't believe in coincidences so if it is near the garbage bin consider that something perishable may have fallen through a crack. Last, close the galley sink valve to the thru-hull and fill it with a bio degradable cleaner and let it soak the hose for a couple of days. If it is trapped stagnant water just get the boat out there and get it moving so it will release some of the water hopefully to the bilge. Also check the refrigerator drain, spilled milk smells like ....... Good luck.

 

[Mikem]

The frig and freezer drain to the shower sump just forward of the start battery. Check that.

 

[Brigadoon460]

Thank you everyone for the suggestions. I have thoroughly cleaned the sink drains/lines. I will inspect the reefer drain lines and sump pump. Additionally, I will see if I can clean under the sole.

 

[Cruising Spirit]

On our 2001 460, one of the first things I had to upgrade when we bought her new was to add a sump pump to the rear air conditioner in the aft port sleeping cabin. The rear air was installed with a hose leading from the condensate pan to the bilge. Just to mention, front air conditioner condensate, aft shower and fridge drains all go to the sump pump under the sole between galley and nav station. Also just to mention, the forward bath drains all go to the sump pump under the port side sole of the forward cabin. It was just the aft air conditioner that was draining to the bilge. This water passes out of site between the grid pan structure and hull, under the galley and engine sump/oil catchment pan, to the center line of the hull...it proceeds still unseen below the engine start battery box through limber holes to the aft edge of the bilge. I installed the sump box dedicated to the aft air conditioner below the cabin sole of the aft port cabin to pump overboard. I removed the start battery and cut a 4 inch hole in the surface that is squarely under the battery. There I accessed the pool of water that builds up due to clogging of the limber hole and sucked it out with shop vac. Set the battery back in, no problem. Keep the new sump pump box running like the others and you will have a dry bilge unless something is otherwise leaking. Or, sometimes we get smell from the galley hoses. Shop vac them out till you see clean sea water or use a drain cleaner with caution. Bilge cleaner also works well down drains and I have had no problem cosmetically damaging any surface with that. Go sailing and the galley drain hose smell will be less of a problem. All the best, Tim at Cruising Spirit.

 

[Richandhelen]

I have the same exact problem. I suspect the proximity to the holding tank which, on my H44, is directly below the galley floor. I do, however, constantly have a slow fresh water feed from both a/c's to the bilge. They run quite a bit here in South Florida (I leave them set to 85 when away from the boat). The bilge constantly has 1" or so of water in it. I don't think it is the sink drain as the smell is not strong at the sink drain itself. And are the sink drain hoses permeable?

 

[Peggie Hall HeadMistress]

I suspect the proximity to the holding tank which, on my H44, is directly below the galley floor...

Unless it's leaking, the holding tank can't be the culprit..although permeated sanitation hoses connected to it could be. However, if any part of a hose stinks, that whole hose stinks...so unless you have the same odor every place that hoses pass through, they aren't the culprit either. And it's also unlikely that your sink drain hose has permeated.

I do, however, constantly have a slow fresh water feed from both a/c's to the bilge. They run quite a bit here in South Florida (I leave them set to 85 when away from the boat). The bilge constantly has 1" or so of water in it.

Bingo...there's the source of your odor. A/C condensate sitting in the drain pan and the bilges iwill "sour" in a heartbeat in hot weather. If it's landing in a pan that's overflowing into the bilges, reroute to the shower sump if you can...or install a new sump that you can clean regularly...or...an off-the wall idea that occurred to me while typing this:

My last boat was a powerboat, a "project" boat I bought from an estate. When I bought her, the a/c condensate drained into the bilge...the line ran down right next to the hull. One of the first things I did was have a thru-hull installed that I could connect that hose to, to drained it overboard. That won't work on a sailboat...but when you wondered about whether sink drain hose could permeate, I wondered whether it might be possible to send your a/c condensate water overboard by teeing its drain line into a sink drain line...??? Like I said, it's an off the wall idea, but sometimes off the wall works.

 

[gypsysoul]

Did you ever find the source of the under sink odor?

 

[Don Lucas]

For these odors caused by air conditioners etc draining into bilge or leaving a puddle of water . you can got to the hardware store and get some air conditioning pan drain treatment tablets.

 

[Peggie Hall HeadMistress]

But first install a drain pan, or better yet a sump. That water needs to be contained, not allowed to migrate all over the bilge when the boat heels. Unless it is contained, you'll be cleaning the bilge regularly. And btw, those tablets are expensive!

 

[Brigadoon460]

I replaced the heads from Vacu-flush to Dometic electric toilets and the issue appears to be resolved. I suspect it was a clogged vent or something along those lines.

 

[gypsysoul]

We have ruled out the sink drain lines, the bilge and the toilet/lines/holding tank/air vent. I have your book Peggie

Our Waeco fridge does not have a drain pan it has a drip tray inside the fridge, and that is clean.

Next step is we are going to pull out the cabinetry...

 

[Peggie Hall HeadMistress]

Odors are always strongest at their source...so before you start pulling cabinets out, stick your nose into all of 'em and every other enclosed space immediately after coming aboard BEFORE opening up and airing out the boat. Depending on how many places you'll have to sniff, you may have to do this a few times, eliminating all the previous negative results each time.

If your nose tests turn out to be 100% negative, I suspect you may have trapped water below the sole. It's been a problem on some Hunters that have a "grid" under the galley area of the boat. The "grid" should have limber holes that allow it to drain, but the holes can become blocked, or the factory didn't bother to install some or all of 'em. If Steve Dion were still around, he'd know what I'm describing...I learned about it from his posts. You might want to search the archives for posts he authored.