Odiferous

atom ant · 08-05-2014, 07:23 PM

OK

I like to sleep with the window open above the bed and the maxair fan on low. (my wife hates me).

I used the bathroom fan - wrong! The bathroom smelled, and under the sink was terrible. I think others have complained of the same on the 36RL and some others. In addition to an anti-syphon vent for the gray tank under the sink, there is in fact also the vacuum breaker associated with the black tank flush system. By design, this is an elevated valve that closes when pressurized to allow water to go into the tank, but when the pressure is off, it opens to allow air into the top and drain water down into the tank to provide an air-gap between the domestic supply and blank tank water. The maxair fan pulls a slight vacuum and draws air directly out of the black tank into the bathroom - YUK.

My fix will be two quarter turn inline valves under the sink, one on each side of the vacuum break, to isolate that system when I am not flushing. I will do both sides, so I don't accidentally dead head that cheap plastic vent and break it if I forget to open them when flushing.

Parts should be "amazon"ed to my house Wed, along with the pex tool. Anyone else come up with a better solution that doesn't compromise the purpose of the anti-syphon valve?

Radio_Flyer · 08-05-2014, 07:27 PM

I ended up replacing the the anti-siphon valve with a couple brass fittings and a brass
Camco 23303 1/2" Back-Flow Preventer. Not only did it get rid of the bad leak, I haven't had any odors at all.

atom ant · 08-05-2014, 07:42 PM

That might have been a cleaner resolve - I'll have to give that some thought before I dig into this!

Radio_Flyer · 08-05-2014, 07:45 PM

I can take a picture and post it this weekend for you. Not getting to the rig anytime sooner.

travelin' texans · 08-05-2014, 11:23 PM

I added a water hose shut off on flush inlet in the convenience center, no more smell. The only smell I have now is when it's time to drain galley, it smells worse than the black.

atom ant · 08-05-2014, 11:31 PM

Quote:

Originally Posted by travelin' texans

I added a water hose shut off on flush inlet in the convenience center, no more smell. The only smell I have now is when it's time to drain galley, it smells worse than the black.

Danny,
I'm not sure that would cure my problem - as you can see from my diagram, when the spring loaded vacuum break under the sink opens, it stays open and allows direct airflow from the tank up through that vacuum break. Valving upstream of the vacuum break wouldn't necessarily stop that.

johnboytoo · 08-06-2014, 12:19 AM

I've never had an odor but maybe I've been preemptive in that I've used this stuff for a long time... not every fillup, but most times...

lwg · 08-06-2014, 12:27 AM

I've noticed that if I don't open a window and run the bathroom exhaust Maxxfan for any length of time I get a serious gray tank odor in the bedroom/bathroom. Turns out we get the smell from the washer drain. Even though it's essentially plugged with clay to somewhat seal it odor still manages to find its way up the pipe.

travelin' texans · 08-06-2014, 12:47 AM

I don't know Brad, but since I added that valve we don't get the odor, maybe it helps vac breaker to work?

johnboytoo · 08-07-2014, 04:32 AM

Well THANK YOU VERY MUCH .... Now we have a horrible odor --- mostly in the basement, but seeps inside...

Haven't been in ours since our last trip in May - been in storage with dead batteries - I repaired the 4/0 cable & cable end that came apart and got it charged so decided to take one last summer fling and WOW....

too bad we can't take pictures of smells

left fans on underneath with doors open and lysol'ed it while we go out to dinner...

my elimonate and black tank stuff didn't do a thing for it...

hopefully running water thru it will rinse it out !

Whew - hope we don't have to get a hotel room

travelin' texans · 08-07-2014, 05:18 AM

JBToo
Sounds like of it weren't for bad luck you wouldn't have any!!

atom ant · 08-07-2014, 05:49 PM

Well parts came in early, so I just did it per the original plan. We will see if it works.

The supply side is the one directly below the valve, and the spray side is the elbow, as I discovered playing with the valves to check for leaks.

Radio_Flyer · 08-07-2014, 08:12 PM

So you basically just put a valve in to close them off? Let me know if that works. My setup is working and no open ball checks in place to let off fumes. That would work if the anti-siphon could have been replaced. Could never get a part number to cross reference a replacement. Your fix should help folks with a working valve that are experiencing the odors.

atom ant · 08-07-2014, 09:51 PM

Quote:

Originally Posted by Radio_Flyer

So you basically just put a valve in to close them off? Let me know if that works. My setup is working and no open ball checks in place to let off fumes. That would work if the anti-siphon could have been replaced. Could never get a part number to cross reference a replacement. Your fix should help folks with a working valve that are experiencing the odors.

Ya, mine just close off both sides of the vacuum break (I used two valves mainly because I didn't want to dead head the cheap plastic vacuum break with pressure if I forgot to open the valve on the spray side).

Plan is to leave them closed all the time unless I'm flushing. I'll open them to flush and it should work as designed - allowing the spray side to drain into the tank leaving an air gap between good and bad water.

I did try it for the day I had left with the fan running for a few hours. No smell, but not really a fair test. Will need to try overnight sometime.

Realistically - nothing should be needed, as the vacuum break spring should somewhat close when there is no longer a vacuum pulled on it while draining the column of water into the tank after pressure is removed, but it must not be seating right or the spring is too weak, or it is just a POS in general. I didn't want to mess with trying to find another. Under pressure it definitely slams shut and holds pressure, as I was able to test it using the valves while the outside pressure was on, but I can't tell how well it seats when all pressures equalize.

johnboytoo · 08-08-2014, 02:21 AM

Quote:

Originally Posted by travelin' texans

JBToo
Sounds like of it weren't for bad luck you wouldn't have any!!

It's YOUR fault....

we aired it out and put some chemicals and more water and all is well (with that bit !)

arcticman1957 · 11-16-2014, 09:17 PM

Radio Flyer I would like to see a picture of your installation. Mine is leaking again.

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