I have 3 Briggs toilets that at times do no flush even just water. 1 downstairs and 2 upstairs. Of the 2 up, they are on opposite sides of the house and different pipes that go into the basement floor. The one downstairs get the most use and fails 2 of 20 flushes. I have put an auger thru the stool and no improvement. Sometimes I have to plunge many many times to get it to flush. What can I do to fix it or should I just replace them. MY sinks, tub, dishwasher, and washer all go into the same drain in the basement and I have not had any issue with them. HELP