Phantom Flushing - Gerber 1.6 Toilet

[Davidhmd]

I have a Gerber 1.6 gpf toilet with a 3” flapper and fluidmaster tank parts. It constantly refills itself. I checked and cleaned the flapper and flapper seat and couldn’t find any problems defects or bumps. I tried replacing the flapper anyway and it didn’t help, and it didn’t seem to fit well even though it was a 3” flapper.

What else should I try or check? I wonder if the flapper seat nut could be loose?

Post title may be wrong. It doesn’t flush itself. It just constantly drains a bit then refills a bit.

 

[Reach4]

Check that the refill tube is held above the overflow tube, and is not inserted down the tube.

If that is OK, turn off the water with the stop valve at the wall. Where does the water level stop falling?

 

[Sponsor]

 

[Davidhmd]

The tube is held in a groove at the top of the tube. There is no clip to hold it above the tube.

With water off for around 8 hours the water dropped about 3/4”

 

[Reach4]

The tube is held in a groove at the top of the tube. There is no clip to hold it above the tube.

With water off for around 8 hours the water dropped about 3/4”

If you can clip the refill tube above the overflow tube, there is a good chance that this phantom flushing will stop. You can buy a clip, or you can fabricate one with water-resistant materials.

Also make sure that the fill level is set to at least 1/4 below the bottom of that groove. Inspect that there is no crack that might have been made while whittling that groove. Some self-fusing silicone tape maybe could let you repair the groove or crack.