Ok, guys. For a little over two years I have been living in an apartment and from time to time each of the three toilets gives an insufficient flush. Not all the time but this should never happen.

What happens is this: the water and waste swirls and swirls but there is little or no downward suction. Sometimes it takes three flushes for a complete flush.

It happens throughout the day but I notice one toilet does it on the first flush of the morning. Thinking maybe the tank bled down during the night, I check the water level - full to the water line. Even holding the handle down and watching to see that the flapper does not flap down prematurely, it happens. Same with other two toilets.

Management sent out quite a young plumber today and he just said that there is no blockage on any of the three toilets. He left. Frankly I do not think he had much experience. He figured out what is not wrong; he did not figure out what is wrong.

Any idea what could cause this? Could the wax seal in all three toilets be failing after twenty five years of use causing some kind of air leak?

And I cannot replicate it generally; of course it flushes fine each time when the plumber is here.

Ideas? I think management just wants to let it ride and go no further to find out what is causing this. I do not know much about plumbing but I know this is not right. This never happened in my house over thirty eight years of living there.