How to Fix a Toilet That Won't Flush Properly
When a toilet won't flush right, it’s usually because of one of three things: not enough water in the tank, a broken part inside the tank, or a partial clog down in the bowl.
Before you call a plumber, you can usually figure out the problem yourself with a few quick checks. Here is a simple step-by-step troubleshooting guide.
1. Check the Water Level in the Tank
Take the lid off the toilet tank and look inside. For a solid flush, the water needs to sit about 1 inch below the top of the overflow tube (the open plastic pipe standing vertically in the middle of the tank).
If the water is too low: The toilet won't have enough power to push everything down. Locate your float (the floating rubber ball or plastic cylinder on a metal rod). If it’s a cylinder style, turn the adjustment screw on top clockwise to raise the float, which allows more water into the tank.
If the water is fine: Move on to step 2.
2. Inspect the Flapper and Chain
While the tank lid is off, look at the rubber "trapdoor" at the bottom. This is the flapper. When you push the flush handle, a metal or plastic chain lifts this flapper to let water rush into the bowl.
The Chain is too loose: If there is too much slack, pushing the handle won't lift the flapper high enough, or it will drop instantly. Rehook the chain to a closer link so there is only about 1/4 inch to 1/2 inch of slack.
The Chain is caught: Sometimes the chain gets wedged under the flapper, preventing it from sealing completely. Untangle it.
The Flapper is warped or dirty: If your toilet is constantly running or trickling, the flapper might be worn out. Run your finger along the rim of the flapper; if it feels slimy, warped, or leaves black residue on your hand, it needs to be replaced (a $5 part at any hardware store).
3. Clear the Rim Jets
If the tank is full of water and the flapper opens all the way, but the water just swirls lazily in the bowl without actually flushing, your rim jets might be clogged. These are the small holes tucked up underneath the inside rim of the toilet bowl where water pours out.
Over time, hard water mineral deposits (calcium and lime) can plug these holes up.
How to fix it: Take a small mirror to look up under the rim. Use an old toothbrush, a bent paperclip, or a small wire brush to gently poke into each jet hole to clear out the crusty white buildup. You can also pour a cup of vinegar down the overflow tube in the tank, let it sit for an hour to dissolve the minerals, and then flush.
4. Test for a Partial Clog
If the water in the bowl rises dangerously high when you flush and then drains out agonizingly slowly over several minutes, you have a partial clog in the trapway or main drain.
How to fix it: Grab a heavy-duty flange plunger (the kind with a rubber sleeve extending out of the bottom, designed specifically for toilets). Ensure there is enough water in the bowl to cover the rubber head of the plunger, insert it at an angle to avoid trapping air, and give it 5 to 6 vigorous up-and-down plunges.
