Bosch Dishwasher won't cycle or spray water. Any ideas?

The model number of the dishwasher is Bosch SHX46A05UC/14. I have checked voltage with a meter, the circulation pump is getting 120v at the pump when it is supposed to be spinning but just sits and hums. The pump came with a new capacitor. Both pumps do the same thing as well as the control boards. Nothing sprays. It will go through a complete cycle , fill, etc, even the soap pops out of the dispenser when it should. Everything else seems to work as normal except the circulation pump. I have take apart the sump further to make sure there aren't any blockages. The aqua sensor looks ok, no build up of anything. It has to be something simple but not sure what else to look at. Any help would be awesome!

@csaab ,

I think that you may be correct.

The impeller in the sump may be jammed causing the motor not to turn

Both pumps do the same thing, no spinning and just humming, one is brand new. I took the pump cover off the old one thinking that was the problem to start with- something stuck in it, since the motor wasn't spinning and just humming. Nothing inside and the impeller moves /spins with the motor shaft, so I know the impeller is ok too and no blockage inside the old motor. Any ideas? I really appreciate the help.

Hi @csaab

It may be that there is only current flowing through the pump motor's run winding which is not enough to turn the motor from a stopped position.

The rationale here is that when power is applied to the motor, current flows through the capacitor to the start winding as well as through the run winding and when the motor is up to speed the motor's internal centrifugal switch operates and disconnects the start winding circuit i.e. no current flow through the capacitor.

Since the capacitor has been replaced check the wires to the capacitor to ensure that it (they?) have solid connections (both ends, all wires) and use an Ohmmeter to ensure continuity of the wires from end to end (that ones you can access anyway). The wire from the capacitor to the motor should have hopefully been checked in the factory since you said that the motor came already supplied with the capacitor

The spare parts diagram shows the capacitor has only two terminals so it is only a single capacitor and not a dual capacitor i.e.. start capacitor only, not dual cap start and run

The motor might be humming because there is no connection to the start capacitor and therefore the start winding of the motor.

The voltage that you are seeing across the motor terminals may be correct but if the start circuit is open circuit the motor won't start as it can't overcome the inertia on the run winding alone therefore the humming

If you could spin the motor by hand once the power was applied it most probably would keep running - don't try this though, too dangerous given the lack of good access

By secure connections I mean that if a wire goes into a plastic plug connector try to gently pull the wire out of the back of the connector or check how loose it seems in the connector when plugged in.

Obviously if you pull too strongly it might come out but normally it is crimped very tightly and won't budge

If you had a dressmaker's pin (with the bead on the end) you could pierce the wire insulation on one side of a connector to touch the wire with the pin and then connect an Ohmmeter to the pin and also to the connector inside the plastic at the front end and check for continuity. As always when using an Ohmmeter, disconnect the power from the machine

If there was enough slack in the wiring you may be even able to have a smell of the connector(s) to see if it smells burnt, (or even looks black when viewed where the wire connects at the front of the plug) indicating a loose connection therefore voltage being dropped across the connection therefore heat

I've looked at the wiring of the machine a little more closely now. The pump capacitor wiring is part of the motor assembly, no poor connections or bad wires for either pump. The capacitor wires bridge into the terminals of the motor. The only wires from the washer connect directly to the motor. A ground, hot, and neutral. The hot (black, I believe) after turning to white through a connector goes directly to the control panel. The neutral (purple, I believe), goes directly to the door switch. The door switch is a three pole switch, the purple from the motor, a brown that goes to the control panel, and a white from the power switch bridged to a brown that goes to the control panel- all in this order.

I suspect the door switch is bad on the motor circuit portion and not sending the pulsing power to the motor/ capacitor? I will do some ohms checking of the switch to see what I find but I think this has to be the problem. Your thoughts?

Hi!

I think I am in the same boat. Sometime ago I did do what you did. Seem to have dislodged that "ball"...

But recently the dishwasher overflowed. Now if I start the washer, the water fills up, but the cycle does not start - arms not getting water. And that "ball" thing is stuck thee for good - I cannot budge it.

Have you found permanent solution to this? Is the solution to replace sump&circulation pump.

BTW. I believe that "ball thing" is the impeller.

Yes, That check ball before the impeller which unseats (I am assuming) to circulate the water. My process was to start the dishwasher, and once the unit was done filling with water, the sprayer should start so I stand there and wait for it to start. Most times it does NOT start, so I undo all the screens and stick a special tool (A paint lid opener ha!) and stick it in there and jiggle the check ball. Put everything back together ( DO NOT RESTART THE CYCLE) and once you close the door, you should hear the sprayer start up. The down side is that every time the cycle changes or you open the door and the sprayer stops--- you have to do it again.

All in all, we are just on borrowed time before I can pay the $100 on my home warranty to have them come fix/replace.