George wrote:
I have a toilet with a Fluidmaster 400A fill valve (installed
by a plumber). It has (apparently) always had this
problem: The refill flow rate is too high. The bowl
fills and the refill flow keeps going and (apparently)
water goes over the "hump" in the trap and down the
drain. The water pressure here is not high. It seems
to me that too much water is coming out of the refill
tube and not enough is coming out elsewhere (wherever
that might be). Can this be adjusted?

To reply directly to me, replace all 'z' with 'a' in email address.


The refill rate is not adjustable. Put a paper clip (or similar)
over the tube to see if that helps the problem. I don't recall ever
seeing a 400-A with too high a flow from the refill.

If the valve shuts off properly when tank full level is reached, then
adjusting the float will not affect it.

If you have considered closing the supply valve (shutoff) partway,
don't do it. Some of those valves will chatter badly if not fully open.

Jim