Frigidaire Dishwasher Error Code E:28

E:28 indicates that the aqua sensor is not properly calibrated or did not run during the wash cycle. The aqua sensor is located at the sump and monitors water clarity to guide cycle adjustments. The fault is triggered when the power module cannot get a valid reading from the sensor, either due to a dirty sensor, a wiring issue, or a failed component.

A reset may temporarily clear the code, but if the underlying issue is not resolved, the fault will return as soon as the dishwasher attempts to calibrate the aqua sensor at the start of the next cycle. Cleaning the sensor or fixing a wiring fault is necessary for a lasting repair. Resetting is useful for confirming whether the repair was successful.

If the fix is simply cleaning the aqua sensor, there is no parts cost involved, only the time for the repair. If the aqua sensor needs replacement, parts typically range from around $20 to $60 depending on the specific model. If the power module is at fault, that repair is more expensive, with parts generally ranging from $80 to $200 or more before any labor costs.

Start by cleaning the aqua sensor where it contacts the sump, removing any grease, scale, or debris that could block its optical surface. Next, check the continuity of the wiring between the aqua sensor connector (b5) and the power module to confirm there are no broken or disconnected wires. If cleaning and connection checks do not clear the fault, the aqua sensor itself may need to be replaced.

The E:28 fault prevents the dishwasher from completing a normal cycle because the aqua sensor feedback is missing, so the machine will not operate as intended. Running it repeatedly in this state is unlikely to cause a safety hazard, but cleaning performance will be compromised since the control system cannot properly monitor water conditions. It is best to diagnose and resolve the fault before continued use.