Pump virus I think, Bicarb pump alarm, no EOS, 1.repair and do mechanical calibration, now no more continuous grinding noise but intermittent, confirm with debug screen that ABIC is not stable, now for the 5th time doing mechanical and problem still exist, replace actuator bd. and sensor bd. together with new cables, and still wont eliminate the intermitent grinding noise, I am waiting for my new pump now, Do you guys think that the stepper motor is the problem or is there any other solution to this problem?

thnx.

The best solution is to replace the pump and when you rebuild your pump don't tighten down on the screws until you here the plastic, just make sure the screws are snug.

Put the original actuator bd., sensor bd. and cables back in. When you see the machine alarming bicarb pump alarm and no eos, the pump is on its way out. Better to replace the pump early than have it crap out during a treatment.

Replace the pump for all the reasons mentioned above.

I totally agree. Relpace the pump! If there is an EOS alarm without grinding noise, do a mechanical calibration.