After flushing the basement toilet it sometimes produced a loud vibrating sound that would usually stop if it was flushed again. Tonight the noise has not stopped after many flushings. I have also tried flushing other toilets and running different taps in the house all to no avail. Any help would be appreciated. Thanks

You may have a loose washer in your angle valve, or bad seal in your fill valve,what type of ballcock is installed in your toilet tank, please see the images, thanks'

John

Thanks, I have the one on the left (400A).

First check the angle valve for loose washer at the end of the stem, you have to shut the water to the angle valve, remove the nut and the stem inspect the end washer for looseness or damge replace it if need,

If angle valve is OK, you need to inspect or replace the fill valve seal, here how you do it,

Close the angle valve under the tank, press down the fill valve top cap and turn it counter clockwise remove the fill valve cap cover, inspect the washer for wear or cracks. If bad replace it Replacing a bad washer is cheap and easy, if you decide to hunt for a washer, remove it and take it to the store to find a match.

Before installing the washer you need to flush the fill valve, Cover the valve with your hand. Turn on the water (cautiously, so you don’t get a cold shower!) and let it flush out the valve for a few seconds.

Check the tank water level, it should be at the mark in the tank or 3/8 to 1/2" below the top of the over flow tube when the tank is filled and the ballcock shut down, for info see the images, Good Luck.

John

Thanks very much for your help.