American Standard Elite Kitchen Faucet: Hot Limit Safety Stop Mystery

For the second time in a few months, the kitchen faucet handle stopped moving all the way to the left and the spout stopped dispensing hot water. The last time I did nothing and, after a few days, it resumed normal operation. Having had a while to think it over, this time I removed the handle and saw exactly what I expected:

The installation manual has a useful diagram:

The red ring (the “hot limit safety stop”) fits into one of eight click-stop positions; the photo shows it in position 5, with 0 being just to the right of the bottom screw and 7 just below the horizontal notch across the middle.

The dark gray plastic feature inside the ring connects the metal handle (the out-of-focus silver stud aimed at you) to the valve assembly. The two lugs sticking out to its left and right bump into the inward-pointing red lugs as you rotate the handle leftward = clockwise = more hot. With the ring set to the 0 position, the red lugs overlap similar lugs molded into the light gray valve body that limit the rotation in both directions.

Observations:

• You must pry the red ring upward to disengage the splines locking it into position
• The gray lugs impose a hard stop in the counterclockwise direction = cold
• There’s no upward force on the ring for any reason that I can imagine
• We don’t pound on the faucet handle, so there’s no shock loading

I have no idea how the red ring could disengage its splines and move counterclockwise by five clicks all by itself.

I reset it to 0, reassembled the faucet with a dot of penetrating oil in the set screw, and it’s all good.

We’ll see how long that lasts …