How deep is the black/grey tank from the floor?

[Burgboy]

Previous owner seemed to screw a rug into back bedroom floor. I keep getting wafts of black tank smell from only the back bedroom and not even in the toilet. How much length is there from floor to holding tanks? I have a 32s

[Dr4Film]

I doubt very much that he used a screw THAT long to actually puncture the top of either the grey or black tanks.

I would check your mechanical vent valves that you will find under the sinks. They are notorious for leaking odors.

[Michael Powell]

Does anyone have a picture of these valves what do they look like...Got similar problem...

[Tom Cherry]

6 hours ago, Burgboy said:

Previous owner seemed to screw a rug into back bedroom floor. I keep getting wafts of black tank smell from only the back bedroom and not even in the toilet. How much length is there from floor to holding tanks? I have a 32s

The question also is, how wide is the tank.  If you can “see” the side of the tank, measure from the side to a reference point on the bedroom side…like a window or something that you can “transfer” to the inside.  If you can’t see the side or such, a inspection camera that wirelessly transmit to a tablet or phone is your best bet.  Snake it up the side and look at the gap.

I’d clean the tank, twice, with a good liquid cleaner….and then start using “Happy Camper”.  See if it goes away.  Remember to put a couple of gallons of water and Happy Camper in the tank while in storage.  The bacteria keeps down odor.  I only fully drain and don’t put in and water when it is winterized.

[Dr4Film]

11 minutes ago, Michael Powell said:

Does anyone have a picture of these valves what do they look like...Got similar problem...

 

[Tom Cherry]

14 minutes ago, Michael Powell said:

Does anyone have a picture of these valves what do they look like...Got similar problem...

Richard has a point.  If you seal this off, using a sandwich bag and tape and it is “leakproof”, the odor will get worse or go away.  It is under the sink in the toilet room.  I still bet on the condition of the tank.

BTW, go to Lowes or a hardware store and buy some silicone plumbers grease.  Turn off the water.  Open the flush valve and use a flashlight.  Growing black junk might abound.  Use paper towel and water and a discarded tooth brush and clean the rubber seal the flush valve or ball rides or seals on.  Re coat the seal and put a light layer on the valve ball.  Repeat every 3 months when in use or when final storage or winter.

 

10 minutes ago, Dr4Film said:

 

Not all Monaco’s built the same.  Mine has NO VALVE like Richard’s, but it does have the one in the picture.

[Dr4Film]

The photo that Tom Cherry posted is used only on the Black Tank Back Flushing System IF there is one installed on your tank.

Whereas the valves that I referred to are used on the grey tank drain lines and found at each sink to allow for better draining of the water as it flows to the tank.

[Burgboy]

2 hours ago, Dr4Film said:

I doubt very much that he used a screw THAT long to actually puncture the top of either the grey or black tanks.

I would check your mechanical vent valves that you will find under the sinks. They are notorious for leaking odors.

3 inch woodscrews

[Tom Cherry]

1 hour ago, Dr4Film said:

The photo that Tom Cherry posted is used only on the Black Tank Back Flushing System IF there is one installed on your tank.

Whereas the valves that I referred to are used on the grey tank drain lines and found at each sink to allow for better draining of the water as it flows to the tank.

Richard, thanks for clearing that up.  That makes sense as it only “dribbles” when I quickly cycle the on off valve I put on the back flush short hose.  I truthfully, after 13 years, have never “spotted” the vents and I have logged a few hours on my back looking up in the 3 sink area.  Next time, I will be more observant.

[Dr4Film]

18 minutes ago, Tom Cherry said:

Richard, thanks for clearing that up.  That makes sense as it only “dribbles” when I quickly cycle the on off valve I put on the back flush short hose.  I truthfully, after 13 years, have never “spotted” the vents and I have logged a few hours on my back looking up in the 3 sink area.  Next time, I will be more observant.

That specific valve is called an Anti-Siphon Vacuum Check Valve. It has to be mounted higher than the black tank flushing device. It is used to ensure that no Black tank fluid is siphoned back through the flushing system once the water pressure has been turned off.

[cbr046]

On our Endeavor I got curious what was behind one of the basement panels, the only one without a door.  On it there's a switch for propane and nothing else.  Once the screws and panel were removed I could see the RH side of the black, gray and fresh water tanks.  There was probably a foot clearance (maybe more) between the top of the tanks and the floor of the coach.  I'm sure the LaPalma is very different, but don't think that floor screw got your tank.

I also get odors in that part of the coach.  I'll have to investigate those check valves.

- bob

 

[dl_racing427]

14 hours ago, Tom Cherry said:

Richard has a point.  If you seal this off, using a sandwich bag and tape and it is “leakproof”, the odor will get worse or go away.  It is under the sink in the toilet room.  I still bet on the condition of the tank.

BTW, go to Lowes or a hardware store and buy some silicone plumbers grease.  Turn off the water.  Open the flush valve and use a flashlight.  Growing black junk might abound.  Use paper towel and water and a discarded tooth brush and clean the rubber seal the flush valve or ball rides or seals on.  Re coat the seal and put a light layer on the valve ball.  Repeat every 3 months when in use or when final storage or winter.

 

Not all Monaco’s built the same.  Mine has NO VALVE like Richard’s, but it does have the one in the picture.

If you don't have an old toothbrush, the wife's works well. 🤣

[Tom Cherry]

8 hours ago, dl_racing427 said:

If you don't have an old toothbrush, the wife's works well. 🤣

If I weren't such a wise @$$, I would probably zing you. NOW, the other "hall monitors and the Principal" can obviously overrule and also zing me for the sarcastic response....I hope your relationship with your wife is as good as mine.  Those souls put up with a lot...especially our "mouths"...

[Bill R]

When I bought our coach I kept getting that sewer "whiff" smell.  I checked the toilet seals, and any penetrations, with no success on finding anything.   As Richard mentions, I replaced all of the original sewer vent valves (Studor Mini Vent), 17 years old, under each sink.  Pretty cheap at Home Depot or Lowes.  Exact same fit. 

Upon examining the old ones, the vent rubber flap was deteriorated and doing my own vacuum/pressure test with my mouth (yes they were clean and washed), I had to create a lot more air flow to get a seal, both pressure and vacuum.  The rubber seats should open/close easily with just the slightest change in pressure.

Final word, NO more sewer smells AT ALL!