I haven't posted much this week as I've been struggling a bit. The wife is away for work this week and I am lost without her. I don't know what I would do without her and this week each year gives me a taste of that and I don't like it, not one bit.
I've also been thinking a lot about my good friend and mentor who passed away 9-years ago this week. I've missed him and missed our bench racing sessions where we'd discuss a lot of topics. He was a great critical thinker, and I always learned from him, no matter the subject.
I didn't schedule any side work this week and to occupy my time this week I have been working on the coach a little. I wasn't going to post this, however, after giving it some thought I feel that maybe someone else with an RV might experience something similar and I wanted to give a place to look.
Let me preface by stating that while driving the past year or so on occasion we've gotten a sewer smell inside the coach, but ONLY when driving and only with partial black tank occupancy. The wife is the first to smell it, but her sniffer is much more in tune than mine. That being said, when it has occurred, I have checked to ensure that there is water in the bowl of the toilet and therefore have that vapor barrier in place. No issues with the bowl holding water so that's not it. I thought maybe a plugged vent, so I removed the vent cap earlier this year and poured some water down it to ensure there were no blockages, nothing noted. I even went through and replaced the AAC (Air Admittance Valves) for the various sinks thinking maybe it was actually the gray tank and not the black, but that was not it either and I'm pretty confident it is the black tank, not the gray producing the odor. Where it only occurs when driving I also figured it must be something being drawn into the interior as there is a negative pressure while driving.
With checking so many things and coming up empty handed most of the year I figured the last remaining piece of the puzzle was the floor gasket at the flange, being 24-years old maybe it has gotten hard and brittle or deteriorated to the point of allowing gasses to bypass, which is really the only thing I could think of because it would have to be something below the water in the bowl. I searched and found a new OEM floor gasket from Dometic as well as an OEM bowl gasket set since I will be in there anyways and it is the same age. We have the porcelain electronic Dometic toilet in our coach so parts are not quite as easy to locate being discontinued for many years now and not a very popular toilet except on some upper tier coaches. After having all of the parts I decided to pull the toilet from the floor of the coach and check it out, especially with the wife not home.
Here is a before picture as I just started removing the cover for the electronics on the toilet and the covers along the floor that cover the hoses and wiring. The box down along the floor is skewed a bit because I have already removed the screws and started removing them before I took the picture.
Back cover removed and electronic control board and wiring disconnected and lowered from the back so the toilet could be removed.
This particular Dometic porcelain toilet is all one piece and must be removed completely to expose the working below. I was able to source the parts from a yacht company in which these toilets were also heavily used in the marine industry at some point. I taped and marked the toilet's position before removing to ensure it goes back in exactly the same location.
Unfortunately, when I removed the base of the toilet which contained the mechanical components I saw nothing wrong with the base gasket at the floor between the toilet and the flange. Well ****, I was fully expecting to see a failed gasket as that is the only logical place the odor could be coming from as it has to be something above the tank, but below the water in the bowl.
Now I'm stumped and upset with myself that I tackled all of this work and didn't find anything wrong.
I procrastinated for a night while I was kicking myself and then on Tuesday night I thought I would use my smoke machine to see if anything jumped out at me, since I was this deep in I really didn't want to just slap it back together without finding something awry.
I masked the top vent.
Then masked the floor flange and stuffed the hose from my smoke machine through the bathroom window and poked a hole through the masking tape and turned the machine on.
Within less than a minute I had smoke pouring out of the holding tank compartment. Deeper investigation showed that it appeared to be coming down from the flange, so I went inside the coach to see if I could note the origin. There was a little smoke in the bathroom, but it was coming up from around the flange and definitely not a leak in the masking tape. I went back in and out multiple times trying to make sense of where the smoke was originating. Down below it appeared to be coming from the upper portion of the flange and being directed straight down into the holding tank bay, but from the top the smoke was coming from the gaps around the flange and where the hoses passed through and run along the floor from the compartment below.
I turned the smoke machine off and scratched my head for a moment. I now knew the odor was coming from below the flange and being drawn up into the bathroom through voids in the floor and hose routing areas so that part was now making sense. I was also glad I at least found something pointing to the odor, but still scratching my head as to where.....
I thought I should pull the flange and my best guess was that the thread sealant had possibly failed where the flange threaded onto the 3" PVC going into the black tank. The smoke was coming directly from that flange area so that was really my only thought as to the source, but at least I had the smoke verifying there was a leak, somewhere.
My next move would be to remove the 8 screws securing the floor flange to the subfloor and then unthread and remove the flange itself to see if I could detect a failure of the thread adhesive, but it was quite tight, very tight actually, to the point I was fearful of breaking the 3" PVC off coming out of the black tank and then my problems would really begin. I grabbed my two large pairs of slip-joint pliers and on opposing sides began slowly working back and forth trying to free the thread adhesive and allow me to remove the flange. Finally it started to unthread little by little and then I could turn it by hand. Unfortunately, I could see some teeth marks on the areas of the flange from the slip-joint pliers and I was concerned I may have to replace it before reinstalling it.
Once the flange was removed I could see a trail of liquid and wondered how it could be leaking. Well, this big crack at the underside of the flange may be the problem.
Yep, therein lies the problem. The flange itself is cracked nearly a third of the way around. At least NOW I know the exact origin of the problem and it can be easily abated.
I picked up a new flange on the way home from work yesterday and thinking about not wanting to damage the OD of the flange with slip-joint pliers upon installation, I thought I would hurry and build a tool to thread the flange onto the 3" PVC.
Hope I didn't gross anyone out, but this is a fact of life owning an RV. There's always some **** to deal with......
Now I can reassemble everything with confidence that I found the problem. The 4 C's come through again. We identified we had an odor leak getting into the interior, I made a mental list of possible causes or origins of the odor and once the smoke test identified the exact area to look, I found the failed component and now just have to install the new one, being the third "C", Correction, and once reassembled I will perform the fourth "C" by Confirming the repair by performing another smoke test to confirm the leak has been corrected.
Thanks for looking.
) and swamped it out, tested it for a bit, all seemed fine and dandy and I bailed.
. So back up I go to test the cable and the POE switch output. Unfortunately I couldn’t bring our cable certifier as it’s in daily use on a major project, that would have greatly reduced the troubleshooting.
