Autofill Leak


Well-known member
Oct 23, 2016
Roseville, CA
I recently replaced a fill valve in the autofill unit (it was 15 years old and was leaking). I used a Fluidmaster 400A which seemed to be one that was well built and rated favorably.

There is a leak somewhere in the valve - I have the tube out of the autofill unit so that I can check to ensure that no fluid is coming from that tube, but there is still a flow of water coming into the autofill unit.

Does anyone have a recommendation on a different fill valve that is better suited for this application?


LifeTime Supporter
TFP Guide
Feb 6, 2015
Chandler AZ
Pool Size
Salt Water Generator
SWG Type
CircuPool RJ-45 Plus
A&A is the manufacturer of your auto fill. Look at the videos linked by @kadavis and @Arizonarob.

If the fill valve is shutting off completely, the inflow of water could be because the fitting in the bottom is cracked - A&A makes fittings to fix that if necessary.

If you lift the lever on the fill valve, does the water shut off completely or does it keep running? Also, be sure the tubing and that hard plastic piece attached to the tubing isn't interferring with the float movement.

I replaced the original fill valve with a Korky from Lowes after 5 years. About 3-4 years later that one failed, so I replaced it with a cheap Fluidmaster I got from a big box store. Still working. I removed the tubing, tied it in a knot to stop the water flowing thru it, replaced it and tucked it out of the way of the float.
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