20 Most Recent Maytag 24 in. DWU7402 Built-in Dishwasher Questions & Answers

The most common cause of this is heating element itself. It has failed. You can test it with a meter to see if it is burned out. It might also be the relay that controls the heater.

I would check the door to see if it is closing properly. If that is ok, then check the door gasket to see if it makes a good seal. If it is worn, then have it replaced.

A solenoid under the bottom pulls a lever that opens a valve that allows water to pump out and into the drain. The motor just runs in the same direction as when washing.

Hello,
From what you are saying yes the timer is bad. It's the only thing that would cause this issue. You can make this repair your self it's simple. Also you can use the link below to look up and order the timer for your dishwasher.
Appliance & Refrigerator Parts

if you are still looking for an answer, i just came across this site trying to find out the same thing for mine. turns out mine was manufatured in oct. 93. you need the model # and serial #....

http://www.appliance411.com/service/date-code.php

make sure you are using auto dish soap, not regular dish soap, then replace door seal

bad water valve.

the water inlet valve has a screen on the water line connection side. it may look clean but most likely the residues have entered the vaslve and is restricting how much water can enter the unit. most units need to have the water fill to just below the heating element.
the water should just touch the element. if it does, water is fine, then it might be a circulation problem with the water pump being plugged, check to see if the pump is plugged.

We have a dwu7400 so i'm not sure it is the same, but above the top arm you should see a serrated ring (looks a bit like a flower petal) and that should spin off and the arm should come with it. There's a snap that holds those pieces together that if you squeeze it with your fingers you can get it out. Just reverse that to put it back together.

open the door with a t-20 torx drive
seperate the panals
the saod dispensor is hel on by two 1/4 in scres
once those a r off the sop disp will pull out giving you acesss to the clip and the groumet

make sure you water is hot enough, manufactures reccommened 120 degrees to the dishwasher, i advise all customers to run hot water at sink til you get hot water then turn dishwasher on, also fill both compartments of sopa, also use rinse aid or jet dry, do not use gel packets. use cascade powder or liquid only.also run the unit through a clean cycle this should be done once or twice a year. letdishwasher fill with hot water. when starts to wash, open door and add 2 cups of white distiilled vinegar and close door and let it go throughas cycle. no dishes. also i reccommened dish majic cleaner sold at walmart or grocery stores. if this dont help then youw wash syatem could be bad or going bad.hope this helps you. try all these things first befor you re[lace uniy or pay to have it looked at.

need your model # to tell u exactly, most just pull straight down, others have caps that hold it in place. unsrew cap and arm should come off.