I have a similar Frigidaire model purchased brand new this year. Under
warranty, I called Frigidaire who said that this behavior is normal. I
insisted that something's wrong. Repair man came, and confirmed that
this is the way it is designed. I even emailed Frigidaire customer
service, who replied: "The arm comes on
during the short wash cycle and alternates with the lower spray arm."

So the upper arm is purposely inactive during Rinse and Hold,
Pots&Pans, Regular Wash. It only activates during light wash and
rinsing. As an engineer myself, I call this a bad design! My dishes
do NOT come out clean unless I make absolutely sure they're well rinsed
before I put them in.

Anyone know if it's possible to change this (by any means possible) so
that both arms alternate during EVERY cycle???

-Disgruntled Frigidaire Dishwasher Owner

Jake wrote:
I believe I am having the same problem. My model is FDB710LCQ0. I've
pulled the dishwasher out from the counter to see if there was some
type of visual blockage on the line running to the upper spout. I
didn't find any blockage, but I did notice the pressure to the middle
arm was extremely low. I disassembled everything down to the ball and
impeller and the machine worked again for about 1/2 a cycle. There is
an extreme difference in the water pressure running to the spout when
it works properly (middle arm spins) versus when the arm doesn't spin.
This makes me wonder if the motor is going bad. I would rather not
spend $120 on a new motor.


mark wrote:
Hi,

I have a 2 year old Frigidaire dishwasher (model number FDB710LCB0).
Before I start, I have cleaned all the filters and checked for
obstructions. Now, the problem is this: During the Heavy and Normal
wash cycles, the upper spout, which supplies water to the middle arm
does not produce enough pressure to spin the middle arm. The lower arm
has fantastic pressure. Only during the Light wash cycle does the
upper spout really spray well, but only for about 30 seconds or so.
Under the filter there is a small plastic ball which sits next to the
impeller blade. The ball appears to perform the function of
alternately plugging up either the upper spout path or the lower spout
path, to allow each arm to operate one at a time (this model is
supposed to have the two arms alternate spraying. I suppose the
impeller is supposed to reverse direction (?) to cause the ball to
travel back and forth on its ramp. I'm at a loss as to what is wrong.
If I remove the ball, both arms work at the same time, but with reduced
pressure on each arm reducing effectiveness. Any ideas?