Bosch Dishwasher SHU53152

I would check for a water flow blockage in the pipes.

Try cleaning the pressure chamber and sump hose, if not this , it is not heating ( heater or pcb)

Maybe the pump isn't working to its full compasity and not pushing water to higher elevation.

Hi,
When my wife started complaining about her dishwasher not getting the top rackclean this is what I found and I wrote a tip about it...

Dishwasher Spray Arms not Spinning


heatman101

Position the spray arms in a certain position. Activate the dishwasher for a few seconds and then examine the position of the spray arms. If the upper spray arm has not moved, then either there is no water coming to the spray arm or the spray arm is clogged.

Many times the washing arms of the bosch and few other models will clog up with old soap or debris.

Try removing arms and clean out any debris by blowing air through unit and if need be a toothpick or dental tool to remove any solid debris that is stuck. Reattach arms and run through cycle. Hopefully this works otherwise it could very well be the pump.

It is important to know that the upscale LG diswashers alternate between washing the top and bottom rack. So it is normal for some arm to not be turning at certain times.
Also, if this dishwasher is set to half load, bottom only, the top arm will never turn.

only the top rack isnt getting clean?
there is a little plastic circle in the middle of the bottom of the upper spray arm. turn it counter clock wise to pull the upper spray arm from the upper rack. make sure that isnt clogged and the spray holes are not clogged. otherwise....

the piece that the bottem spray arm plugs into and runs along the back wall of the tank to the top is called a feed tube. pull the bottom spray arm out. now you can see the part of the feed tube that feeds the upper spray arm water. does it pop out freely and easily? if so then you need a new feed tube, if not then its most likely your not achieving the right water level or your impeller connected to your circulation pump(motor) is clogged not supplying enough water pressure to travel up the feed tube to spin the upper spray arm.

there is a blockage but may not be obvious. arm turns only by water spraying out of the angled jets at the end of the arm. take arm off, run water thro the centre hole and this is udually enough to force the debris to the jets. clean out and check

have you seen whether water is pouring out of the bottom supply tube with the lower arm removed? not 100% sure on this model but some units have a half load switch but that should turn off the top one. there may be a blockage in the lower water supply tubeways.