I recently moved into a new house and I've been facing an irritating issue with the toilet. It runs briefly every 15 minutes, so I figured it must be the flapper and replaced that. But the problem persisted, leading me to replace everything inside the tank with a complete kit. I also swapped out the plastic triangle part at the bottom since it had three screws. However, the water level in the tank still drops slowly, triggering a brief refill after about 15 minutes. I've checked for any visible leaks and found nothing outside, but I've noticed that food coloring added to the tank ends up in the bowl. I've already changed out most components, but I'm at a loss about what to do next. Should I try switching the flapper again or is there something else I might have missed? I'm even considering just calling a plumber to install a new toilet. Help!
3 Answers
If everything else fails, have you thought about the spud nut? I had a similar problem and replacing it resolved my issues after trying to change every other part in the tank. A small fix might save you from the hassle of a new toilet!
Good call. I only realized after changing out all the big parts that it was a small seal that was causing the issue.
It might be worth replacing the toilet fill valve seal if you haven't done that yet. That was the culprit for my toilet a few months back—found it cheap and it fixed the issue quickly! Just a little rubber part can save a lot of trouble.
Totally agree! That was my issue too. Replacing that small seal made a huge difference in stopping those annoying refills.
I had to do the same and it worked like a charm! Just make sure you get a good quality seal.
Sounds like you're on the right track with the food coloring test! If it’s going into the bowl, it could be a faulty flapper or perhaps the seat isn’t quite right. Even with a new flapper, if it doesn't sit properly in the seat, it'll leak. I’d also suggest checking the height of the fill tube; if it's too long, it might create a siphoning effect that could cause those phantom flushes. Just cut it a bit shorter if that's the case.
Ensure there’s also enough slack in the chain to the flapper so it seats correctly. Sometimes it’s just those little adjustments that make a significant difference!
Yeah, I had a similar issue! My fill tube was actually dipping into the overflow, causing that intermittent fill. I just trimmed it and everything stopped!

I replaced mine after struggling with leaks for ages—definitely worth checking out! You might be surprised how much a little piece can do.