This is the answer.
Early in our relationship, my gf asked me to look at the toilet in her guest bathroom, which was running. The toilet was original to the house, but in OK condition overall. I told her I could “replace the guts” in the tank. She told me she’d rather just replace the toilet, so she’d contact a plumber.
I told her there was no need for a plumber. She was skeptical, but we went to Lowe’s and she picked out a toilet. The salesman asked if we needed a wax ring. Not knowing what I’d find when I removed the toilet, I replied, “two”.
Long story short, I replaced the toilet. Shortly after that I moved in. I sometimes wonder if things would be different today had I not been so good with DIY plumbing.
BTW, here’s my experience of how much a leaking toilet can cost:
Ok so I changed the flapper and the leak has reduced to a drip every 10 seconds or so which ends up being about an inch worth of water level after an hour and a half. Not sure if that math works out but the water level decrease was real. I checked the flush valve and didn’t feel any calcium deposits so I guess that’s the next thing to replace? I mean the leak is 95% fixed but I figure I should fix it to 100 while I’m at it. Any ideas?
You might try a different brand. Not all flappers are created equal. I had problems with Fluidmaster in the past, switched to Korky and problem solved.
I think it’s been mentioned, but I’ll mention it (again if necessary).
Sometimes it’s not the flapper or outlet valve. It’s the seating surface of the outlet pipe.
It could be corroded or encrusted with minerals, which would present an uneven surface that the flap seals poorly against.
How to proceed depends on the cause.