Toilet worked fine for years but recently noticed it requires a 2nd flush. Sometimes the first flush doesn't seem to do much at all in clearing the bowl. The second works like a champ. I just feel silly waiting there for the tank to refill so I can activate the 2nd flush. Its a Toto 1.6 Gal.I believe. The valve and flapper were replaced about 15 months ago with ToTo parts. The water level look good; no leaks; no phantom fills in the middle of the night. Any advice most welcome.

When the toilet has been sitting unused for a while if you remove the top of the tank and look inside you are saying the water level is up to where it should be? Mark the top of the water with a marker on the inside of the tank.

Then while looking into the tank flush it and watch the flapper valve at the bottom of the tank and how it moves. It will rise up to let water out of the tank, then the flapper will lower as the water level in the tank drops. After that 1st flush and when the tank refills notice if the water level goes above the mark you made earlier. Then watch this process inside the tank again as you flush it again, see if anything is different. You said the 2nd flush works fine, just the 1st flush that is not adequate. You should be able to see a difference as you watch both flush processes. Any difference you see will help determine what the problem is.

I know you said the water level in the tank is ok. But what you are describing sounds like the water level is not as high as it should be before the 1st flush so you get a poor flush. Then the tank refills and you immediately flush it again so this time you have the required amount of water for a good flush. Are you sure the tank water level is as high before the poor 1st flush as it is right after it refills?

If you think the flapper could be closing too soon you can try this: When you flush it the 1st time and are expecting the poor flush try holding down the flush handle with your hand for several seconds to keep the flapper raised up, see if that allows the 1st flush to be a good one. If so then possibly you need to replace the flapper, consider installing one that has a delayed closing feature so that it will allow the max amount of water to leave the tank when you flush. With these low-volume toilets you often need every cup of water possible to go from the tank to the bowl during a flush that involves solid waste and paper in the bowl.



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Could be that the holes under the rim could be starting to clog. Squirt some LCR up under there and let her soak a bit.