If your toilet is getting lazy — that is, if it’s not flushing as well as it should be — it probably just needs a little attention.
A toilet flushes by quickly filling with water, which begins the flush. Then siphoning action from the p-trap finishes things off. So a few things can lead to poor flushing.
There could be something lodged in the trap. You can try using a plumber’s snake to get it out. This will work for paper clogs and the like, but an actual object can slow things down by creating an obstacle to solids, and the snake might slide right by it. Plunging may help to dislodge the object.
But in fact, poor flushing is more often a result of the water flowing into the tank. Improve this, and you’ll improve your flush.
Start by checking the tank. If the water level’s too low, not enough gets into the toilet bowl with each flush. The tank is designed to work with a certain amount of water, which may be marked on the inside of the tank. But if it’s not marked, try adjusting the float so the tank fills up a little more (without letting it run into the overflow).
Another possibility is mineral deposits building up on the holes or jets through which the water flows into the tank. By blocking the flow, they cause the bowl to fill too slowly, and restrict the ability to flush.
Clean out the holes around the rim with a small sharp object, such as a compass point. And scrape at the jet at the bottom of the bowl with a table knife. Also, avoid using solid disinfectant tablets, as they can cause blockages.