Re: F4 on adp5966 whirlpool dishwasher
Ur best bet is to clean/replace the pressure switch, i bet its all gunked up with food residue, ( the swich can be removed by reaching in through the access panel at the bottom, its slightly obstructed by the heater but with a bit of care can be squeezed out, alternativly you can clean it by removing the filter and scrubbing it with a brush )
i find this is the cause in 90 percent of f4 cases, this is of course assuming there is nothing blocking the pump !!!