Toilet Won't Stop Running
Water trickling into the bowl, the tank refilling overnight, or a "phantom flush" every few hours? Lift the tank lid and try these checks — most running toilets resolve in under five minutes.
Estimated time to work through: ~5 minutes
The tank lid is heavy porcelain — handle with care.
Lift it straight up using both hands and set it flat on a folded towel on the floor. Dropped tank lids crack on impact, cut deeply, and almost always need to be replaced (and the lid alone can cost $80–$150).
Water on the floor around the base is not a running toilet.
If water is pooling on the floor near the base of the bowl, that's a wax-ring failure (the seal between the toilet and the floor) and a maintenance request — not something to troubleshoot yourself. Subfloor damage compounds fast. Stop using that toilet and submit a request immediately.
Three Parts. That's It.
When you flush, the trip lever lifts the flapper (a rubber valve at the bottom of the tank), which drops water into the bowl. The fill valve then refills the tank. The flapper drops back down to seal the flush valve. If any of those three parts isn't doing its job, water keeps flowing — either into the bowl (flapper leak) or into the overflow tube (fill valve set too high). Both make the tank refill repeatedly. Both have simple fixes.
What you can safely check
- The chain length and slack
- Whether the flapper is sealing (food-coloring test)
- The water level inside the tank
- Whether the flapper seat is dirty
What requires a maintenance request
- Replacing the flapper, fill valve, or flush valve
- Anything beyond the tank — pipes, supply line, shut-off valve
- Water on the floor around the base
- A toilet that rocks when you sit on it
The 6 Steps
- 1
Listen and observe
Stand near the toilet and listen. Is the water sound continuous (a steady trickle into the bowl), or does the tank refill every few minutes with no flush? Continuous trickle = flapper not sealing. Periodic refills with no flush = phantom flush, almost always a slow flapper leak.
- 2
Carefully remove the tank lid
Lift with both hands, set flat on a folded towel on the floor. Don't rest it on the rim of the tank — it can tip and fall.
- 3
Watch the water
Inside the tank, look at the overflow tube (the open vertical pipe in the center). Is water spilling into it? If yes, the water level is set too high or the fill valve isn't shutting off. Skip to Step 5.
- 4
Check the chain
The chain connects the trip lever to the flapper. It should have 1–2 links of slack — enough to let the flapper drop fully when you flush, not so much that links can hang under the flapper and prevent it from sealing. Adjust if pinched, tangled, or wrong length. If slack looks fine, continue.
- 5
Adjust the water level
If water was spilling into the overflow tube (Step 3), find the float — either a ball at the end of a metal arm (older toilets) or a cup-style float around the fill valve (newer toilets). Adjust it downward so the water level sits about 1 inch below the top of the overflow tube. Most floats have a small clip or screw for adjustment. Flush and watch — water should stop refilling before reaching the overflow.
- 6
Try the food-coloring test (Section 5)
If the flapper is the suspected cause, the test confirms it in 15–30 minutes. Jump to the test →
The Food-Coloring Flapper Test
This is the test plumbers and water utilities use to confirm a leaking flapper. Endorsed by Kohler, the EPA, and the NYC Department of Environmental Protection. It takes 15 minutes and resolves the question entirely.
- Take the tank lid off (carefully — Section 2).
- Add 5 to 10 drops of food coloring to the tank water (any color — dark blue or red show up best).
- Do not flush. Walk away for 15 to 30 minutes.
- Come back and look at the water in the bowl.
If the bowl water is clear
Your flapper is sealing. Look elsewhere (Steps 3, 4, and 5 above).
If the bowl water has color in it
Your flapper is leaking water into the bowl. Submit a maintenance request to replace the flapper. We typically resolve these within the SLA window for routine maintenance.
Stop And Submit A Request If…
Submit a request when any of these apply:
- The food-coloring test confirmed a leaking flapper
- Water is spilling into the overflow tube even after lowering the water level
- The fill valve is hissing or running continuously after lowering the float
- Water is pooling on the floor around the base of the toilet
- The toilet rocks or feels loose when you sit on it
- The handle is broken or the chain is broken
- You see visible cracks in the tank or bowl
- The water shut-off valve at the wall is leaking or won't turn
Hard water = faster flapper wear
Florida's hard water deposits mineral scale on the flush valve seat and inside the fill valve. That means flappers in Florida homes typically wear out faster than the national 5-year average. If your flapper is leaking, replacement is a routine maintenance call.
Never use drop-in tank tablets
The blue/colored cleaning tablets that sit in the tank are made with bleach. They destroy flappers in months. They void some manufacturer warranties. Most Sea Dog leases prohibit them. If you want to keep your toilet clean, use an in-bowl cleaner or a brush — not anything that goes in the tank.
Four Habits That Prevent Running Toilets
- 1
No drop-in tank tablets, ever. This is the #1 cause of premature flapper failure.
- 2
Don't flush anything but toilet paper. "Flushable" wipes are not flushable. Paper towels, feminine hygiene products, dental floss — all of these clog and damage parts inside the tank and the drain line.
- 3
Listen for refills with no flush. A phantom flush is your early warning that the flapper is starting to fail. Report it before your water bill jumps.
- 4
Report wobble or rocking immediately. A rocking toilet means the wax ring is compromised. Subfloor water damage costs thousands more than the wax ring itself.
More From The Library
Browse all troubleshooting guides
Self-help guides for tenants, by Sea Dog.
What This Guide Is Built On
Sea Dog's guides are grounded in manufacturer documentation. For running-toilet troubleshooting we draw on Kohler support, Moen and Delta support, the EPA's WaterSense program (fix-a-leak guidance), the NYC Department of Environmental Protection's toilet-leak-detection page (origin of the food-coloring test), and trade plumbing guidance from Roto-Rooter, This Old House, and Family Handyman.
This guide is educational and does not modify your lease. It is not professional plumbing advice. If a step does not resolve your issue, or if you have any safety concern, stop and submit a maintenance request through the tenant portal or contact Sea Dog at the tenant maintenance line. In any conflict between this guide and your signed lease or applicable Florida law (Florida Statutes Chapter 83), your lease and Florida law control.