How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Dales-Electronic Your Own Question
Dales-Electronic, Home Appliance Technician
Category: Appliance
Satisfied Customers: 1483
Experience:  I am a Home Appliance / Refrigeration Technician of 25yrs+ with my own business and for multi-brand national companies.
Type Your Appliance Question Here...
Dales-Electronic is online now

Bosch dishwasher classiXX. Intermittently doesn't drain

This answer was rated:

Bosch dishwasher classiXX. Intermittently doesn't drain either 20min from - or at end of cycle. Impeller moves freely, no debris around impeller, flexi drain pipe not blocked, house drain not blocked. Plastic 'flap' near impeller moves freely. Motor works on bench test.
What else could it be?

Have you checked that the pump is actually receiving power? If not disconnect the pump wires and with a multimeter check if power is being supplied to the pump during the end of cycle pump our or initially on start up of the program (first few seconds) - Ian

Customer: replied 1 year ago.
No, having now assumed that an input condition is the issue, maybe a sensor is preventing the pump to be commanded to drive??
What sensors/blocked air pipes might there be - to stop a vacuum being created if this could be a factor?

It is much more likely to be the power cables to the pump, the pump itself or the main pcb that is at fault. If as mentioned earier you start the appliance the pump will pump for the first few seconds, certainly within the first ten after start up irrespective of sensor input.

Customer: replied 1 year ago.
ok, with that in mind, I have 'stretched' the relevant pump conductors within the loom around the door hinge whilst completing a continuity check - none appear broken. I have wired a simple neon across the pump terminals in order to remotely view when the pump is energised. It runs (light on) at start for around 10 seconds when m/c started a rinse and on this occasion emptied the m/c at the end. I will monitor the neon and advise further.

OK I await you observations.

Customer: replied 1 year ago.
The dishwasher has worked all week - until this morning!! The display indicated 49min left and the water was not pumped out. On a positive note, my slave neon was on indicating 230V across the pump terminals. It has since worked this afternoon. I will order and replace the pump.

OK would you at this point rate the information given sofar, once done all further questions are free of charge. I would if I were you check the actual voltage across the pump connectors. A neon will work from about 80volts upwards - the pump however will only rotate from about 180volts upwards.

Dales-Electronic and other Appliance Specialists are ready to help you