I rent in a highrise apartment building. It can take upward of a year when asking the landlord to check for obstructions in the ventilation and/or clean the conduit, e.g., as might be prompted by lots of condensation after showering, leading to mold.
I have a sewagy smell in the bathroom, especiallly pronounced when I've kept the bathroom door closed. I fear that it might be the bathtub P-trap, as the sink P-trap was recently cleared of obstruction (after years of slow drainage — I usually try to find work arounds for as long as possible before imposing on the landlord for servicing). Perhaps there is a leak in the bathtub P-trap, or there is a strand of something that wicks water out. I did not imagine that it would be trivial to pull up the bathtub to inspect this, and shining a flashlight down reveals that the drain pipe immediately dekes horizontally. If online images are any indication, it likely meets a vertical pipe for the overflow, and then curls into a P-trap.
Since I anticipate much resistance and delay to a nontrivial request to check the bathtub P-trap, I considered renting a drainage camera to look myself. They're quite expensive, with limited options in my city. Two offerings I found were for $220 and $150 per day. I also found that a hardware chain with continental presence (Canadian Tire) sells a cheap camera for $300 ("MAXIMUM Inspection Camera"). So I might just buy one at twice the cost of renting, which gives me the freedom to re-inspect if necessary.
Can such cameras typically see whether the P-trap is water filled, or is there an large uncertainty in their effectiveness? I don't want to blow $300 on a course of action for which there is (say) 50% chance of being able to see the water with some degree of certainty. I found a youtube video alluding to seeing reflection off the water in a P-trap, but frankly, I couldn't make anything out of it. If it takes a highly experienced eye to recognize such a reflection, or otherwise discern whether sufficient water is present, then that reduces the chances of effectiveness of this "solution" for me.
Best Answer
Yes, they should get you the answer you seek. It should be plainly apparent whether there's water standing or not.
You can buy cameras that do what you need for much less. Note that there is variety in the type and rigidity of the cables, so read carefully.