Lazy Daze Owners' Group

Bathroom smells like urine- NOT sewer gasses

June 25, 2025, 09:05:39 pm

I’m at my wits end. I’ve tried deep cleaning this bathroom. I cannot find any signs of leaks in bathroom or the cavity below. I used a black light and an enzyme urine cleaner. Hours later today and the urine smell is back. It does not waft through the motorhome. It is localized to the bathroom. The shower P trap is dry and the shower smells just fine. It’s just a musty urine like smell. I crack the ball valve in toilet and let the smell waft up and get a stark reminder I’m not smelling the sewer gasses. That smell burns my eye brows off.

I have an older Sealand / Dometic 510 toilet. I replaced the seals months ago (flange foam seal, and the two sandwiched donuts) and only recently it began to smell like urine in there. I need ideas on what this could be. I used Roxie and Rocco’s pet stain remover which breaks down uric acid crystals in pee, let that soak in toilet, walls, floor, for over 30min then wiped it down. Cleaned again with magic eraser and Lysol. Smell is back.

Re: Bathroom smells like urine- NOT sewer gasses

Reply #2 – June 25, 2025, 11:19:04 pm

Hi William; I know your situation.  I have the same toilet and had one bolt break when I tried to compress the foam gasket.  I took off the toilet and inspected the floor flange.  In the picture you can see an arrow #2 pointing to part of he problem. The hole cut in the vinyl didn't match where the pipe comes through.  The red liquid on the 8 floor bolts, should have been stainless, is naval jelly (phosphoric acid().  The slots in the screw heads were unusable and so I filled them with Bondo to get a flat surface for a new foam gasket.  Tightening the new bolts on a new, pretty stiff foam, cut holes in the gasket.  Liquid had sloshed around in the tank and leaked out into the subfloor, and rotted the floor just in front. Not flat on the floor, the flange had moved up in back, and the clearance was wrong for the proper compression of the new gasket.
    I cut and placed four sections of aluminum flat bar 1/8" thick around the flange. Glued with sealant and screwed down with stainless wood screws into healthy wood, this provided a level resting place for the toilet pedestal, that allowed the foam to variably compress to make up for the tilt of the floor flange. I have a shag bathroom carpet, cut and removable for washing that fits under the shroud that goes around the pedestal. Out of sight and now with no smell.
    I suspect that you have a similar vapor path.  Does your bowl hold water well?  There isn't a 'P' trap (I couldn't resist that pun!) in an RV toilet, so if water leaks out, so might urine.
    I also renovated a 2001 MB for a friend; and the previous owner had teenage sons, and various members of a scout troop, who had terrible aim!  The wood electrical tray behind the toilet got a new, slanted away from the wall, polypropylene surface. Quite a needed cleaning and epoxy washable white paint. ( this was in a  MidBath).  RonB

   I forgot to add the picture and it won't let me add it to this post.

Re: Bathroom smells like urine- NOT sewer gasses

Reply #4 – June 26, 2025, 11:35:27 am

Hi Andy, I've done that successfully before. The file is about 10 Mbyte jpeg, but I kept getting the error that it was over 50 Mbytes.
    " error: There was a problem during the uploading of 20230822_162935.jpg.
      Your file is too large. The maximum attachment size allowed is 8,096 KB. "  But under the Add Photo header it states that:
     "maximum individual size 49,152 KB"  (50 Mbytes)  So it is identifying the pic as an attachment, not a photo. (It was late)

    The picture was of the screw gap in the floor flange where liquid was seeping into the wood (likely for years). Because of the way the T/K is built, people have a tendency to lean forward to the right, towards the shower. The flange lifted out of the floor at the back, and sank into the floor at the front right. About an 1/8" up in back and 1/8" down in front where the pedestal rests on the floor. So now the pedestal is 1/8" taller and resting on the aluminum tabs, which are level and based on healthy floor. (the tabs don't show.)
           RonB