Accident or not, if the tenant plugged the old one, he is responsible for replacing it.
Flushing ANY solid objects down the toilet radically increases the chance of a plugged toilet.
The main toilet pipe is partly plugged after where the upper pipe joins the lower one.
Because the drain is plugged downstream
The toilet itself is plugged or the pipe from the toilet to the drain is plugged. It may be that the tub and sink have their own drain pipe that may connect to the main away from the toilet drain. Plunge the toilet or sometimes if you fill a 5 gallon bucket with water and pour it into the toilet as fast as it will take it, that will flush out the line. It is a greater amount of water all at once an forces out what the clog is.
Your drain line is plugged somewhere after your shower and toilet line are connected. The reason for the gurgle in your toilet is because air is trapped in the drain and your toilet is the closest place for air to flow to. If you had a vent on your toilet trap arm then it would gurgle in the vent rather in your toilet but your drain is still plugged and needs to be snaked out and maybe your drain line needs to be examined for right grade or broken.
Most plumbers would charge 2 hours to replace a complete toilet.
This depends how you are perceiving this "pressure going up and down" . I've repaired and replaced toilets for years and couldn't imagine how I'd gauge pressure doing this. Maybe you are mistaking pressure for flow rate and something is plugged up somewhere in your toilet.
hi im on city water and toilet isn't plugged but it doesn't flush all the way like there is not enough pressure
either the vert is plugged and there is no air getting through or there is no vent at all
Check the flapper and re-adjust the fill height.
yes,possible when a person is blind
well