I think we’d all like to know the brand of this dishwasher, that needed such a fix after just one year. My 6 yo Bosch 800 has never needed a repair of any kind…and, we’ve never needed to clean the filter.

There were very few dishwashers in the past that used a float to control the normal water level. Fill periods were timed, usually two increments of the timer or two to three minutes. Floats were for overfill protection, in case of a drain obstruction and all the water didn't drain so the next fill period didn't overflow. They didn't prevent overflowing if the inlet valve hung open.

Old KitchenAid used a pressure sensor (like a washing machine) instead of a float to shut off the inlet valve for overfill protection. There were a few vintage brands that used a pressure sensor for the normal fill level.

A reason for basing fill levels on the motor load is to allow different fill levels sensed by the control electronics for various cycles or phases of a given cycle. Such as a 1-hr (non-eco) cycle that fills with more water for stronger spray pressure or to operate all the spray arms together vs. other cycles that take less water and alternate the arms. Or an upper-only or lower-only rack option that takes less water.

thanks for your response. everything you say makes sense. my old maytag worked for 15 years. it had an overflow float and switch. never did anything bad but all the rollers wore out. so now when the new machine overflows the overflow hose fills up the tray under the machine and sets off an error. i suppose a different way to check for overflow.

the question remains about how to fix it. It has only happened once in a year.

the dishwasher is a maytag mdb4949skz.

hi dadoes

thank you. you may have given me the explanation. if the dishwasher was not fully empty when a new cycle started then it would overfill draining water into the tray and setting off the error message F8E4. unfortunately the manual is very misleading.

all real good points dadoes. thanks. none seemed to apply in my case. I notice that at the beginning of any wash cycle there is a drain cycle which makes sure there is no water in the tub starting out. in this way they try to make sure not to overfill. I suppose I have to wait and watch for an overfill. it may have been a glitch in the timer or a power serge or something like that.