Bosch Dishwasher stopping mid wash

Brand: Bosch
Model Number: SHXM78Z55N/20
Main Symptom: stops shortly after start with no error code
What happens & when:

Issue started about 1-2 months ago

Wash stops shortly 3-5 mins after starting with no error code. Display shows 0:00 left

Frequency of issue worsened, from about every other time to about 8 out of 10 times

Observed the water intake spin wheel sometimes spins slower

Bubbles around the spin wheel area

May I get some help identifying the root cause of the issue and parts needed? Thanks

Let me know if additional info needed

Error Code (if any):
Parts or tests already tried: main power board replaced
Photos / video link:

Does it look like it is putting enough water in the tub? If not, try manually adding a couplie of quarts of water to see if it will go into the cycle.

There is water covering the bottom of the tub. However, since the timer comes down to zero, a restart would begin the cycle all over from the beginning, which would drain the existing water to begin.

A couple of things come to mind. There is a flow meter embedded in the clear plastic inlet assembly that measures water going into the tub; it could be off and not reading properly. The heater that is built into the wash motor may be bad. For the short time it runs, does it seem to be heating the water? If you have an amp clamp and know how to use it, youshould detect a amp draw when the heater comes on.

Thank you for getting back to me, David.

For the short amount of time it runs, I noted the air was warm when opening the door, indicating the heater was probably working ok.

I have an amp meter, but would like some guidance on where to apply the instrument to test it.

Thank you.

Another observation is that on occasions when the wash actually completes, the machine stops before completing the heating cycle. This has happened consistently a few times.

I actually just replaced the water intake housing and the problem persists.

could you help explain how the heater may have caused it? And if need to replace what specific part should I look for?

Thank you.

The heating element is embedded in the wash or circulation motor. If the control board does not detect a temperature rise, it will stop the cycle. This keeps the DW from going through a cycle with water that is not not enough to be sanitary. That is why I wondered if the water was getting hot.

Thank you, David.

I’ll do more runs and keep checking the water temps to verify if it’s consistently not reaching desired temp.

In case of a heater replacement, is the following part the right one?

https://www.appliancepartspros.com/bosch-heat-pump-12008381-ap5984938.html

Yes, that is the correct part