I have a GE dishwasher; spray arm at the bottom does not rotate.

The handles slipped down keeping the spray arm from rotating thus causing it to rest against the heating element. It won't wash because of the hole in the bottom spray arm. You have to replace the spray arm before nything else can be determined.

Probably blocked spray arms is the cause of the unit not cleaning properly or rotating. Remove each spray arm (there are 3 in total) and check and clean all the holes as this is where the water sprays out from to clean the dishes and glasses. When they are blocked you get poor wash results.

Check the small holes on the spray arm. They are most likely plugged. (candy wrappers, tooth picks, popcorn or watermelon seeds, you name it.) Sometimes you can clear the holes out, other times it is just as easy (and not very expensive) to replace the spray arm(s). List your model number if you need part numbers or instructions on removing spray arm.

Please check: Does the arm turn freely?  Are the jets clean and spray in the right direction? If not you may need to replace the arm.

check to make sure you are getting enough water entering the dishwasher. If you add a liter of water, does the water arm turn then? If so, you may have a faulty water valve that is not allowing enough water to enter to turn the spray arm. Hope that solves it :)

Yes!

The wash arm(spray arm) is not a tight fitting item,as for the noise the when spraying have a look at the spray arms the are a few holes on each side and top and bottom of each arm,you will need to remove the arms of possible they normally have a quik release system where you push two small fingers together and the arm releases,then inspect these holes and you will probebly find that some are blocked this cuases a uneven flow of water and thus makes the arm rotate un even and make a noise if you find there is food of sorts in these holes remove and put the arms back and that should take care of the increased noise.

Make sure the spray arm is actually rotating and the jets aren't clogged. You should be able to hear the arm rotating when the dishwasher is operating.

Otherwise, perhaps the pump is plugged or not working and the water isn't "jetting"

if the arm is rotating freely when you give it a push by hand, then the problem is blockage in the jets in the arm - the arm only rotates with water coming out of angled jets at the end. take arm out, spray water in centre hole and whatever is blocking the jets should become visible. prize out with a paperclip or similiar

Open the door quikley while the washer is running. Is the spray arm spraying up and rotating. If not you may have a bad seal under the spray arm or a cracked one.