Supply Shutoff Toilet Repair Q&A

Found a slow drip coming from behind the toilet about a month ago — nothing alarming, just a little moisture on the floor that I chalked up to condensation. But it's gotten steadily worse, and now when I try to turn the angle-stop valve fully clockwise to cut the water supply, the flow barely slows down. It's not shutting off the way it should, and I can't tell if the valve is corroded, worn out, or something else entirely.

This is an older home with what looks like original plumbing, and I suspect the hard water here has been doing a number on everything over the years. I've tried cranking the handle as far right as it'll go, but the toilet tank keeps filling like the valve isn't even there. I'd like to figure out whether I can clean or repair the existing valve, or if I need to replace it altogether — and if so, what kind of replacement I should be looking at.…more

Looked under the tank this morning and spotted a slow drip coming from the supply line — there's already a small puddle forming on the floor. Got my tools out and I'm ready to tackle this myself, I just want to make sure I understand what's actually causing it before I start swapping parts. The line doesn't look obviously cracked, so I'm not sure if it's the fittings, the washers, or the line itself that's the problem. Is this something I can diagnose and fix on my own, or are there situations where I'd need to call someone in?…more

During a conversation with a plumber who came out for a running toilet, he mentioned I'd need to shut off the main water supply to the house before doing anything. That seemed extreme to me — I've seen what looks like a small valve right behind the toilet near the floor, and I always assumed that was specifically for shutting off just the toilet without cutting water to the whole house. Am I wrong about that?

I'm trying to handle some of the simpler repairs myself now that I own this place, and I'd really like to understand how that little valve works and whether it's actually safe to rely on. The plumber made it sound like those valves are unreliable, but is that a reason to bypass it entirely, or is there a way to test it first?…more

Nobody wants to spot this, but looking at the base of my toilet tank right now and there's a slow, steady drip forming right at the point where the supply line screws into the bottom of the tank — there's already a small damp patch on the floor underneath it. The connection itself looks intact, nothing is visibly cracked or broken, but there's clearly moisture weeping out from around that plastic nut every time the tank refills. I've gone ahead and snugged the nut a little tighter by hand but the drip came right back once the water pressure kicked in again. Is this something wrong with the nut itself, or is there a washer or seal inside that I need to replace? I'd really like to fix this without pulling the whole line off if I can help it.…more