Dishwasher Not Heating Water

[Carbo]

The unit in question is a 7 year old Kenmore. I first noticed the problem about six weeks ago, when opening the door to empty the dishwasher and there was still some powdered soap in the soap cup. Since then, this has been a constant. The soap is never fully incorporated into the wash cycle. Not only that, as time has passed the amount of soap remaining in the cup has grown. Meaning, less and less soap is being used, with the result being the dishes aren’t coming out clean any longer. I’ve checked to be sure the cup is always fully opened and it is. I’ve changed brands of powdered soap but still the results are the same. I have even tried different wash cycles but still the soap remains and the dishware isn’t being cleaned very well.
I have tried adding water before the main wash cycle begins, thinking the level might be too low due to a bad water inlet valve. Didn't help, valve OK.
Then I tested the water temp and, sure enough, it is only 110 degrees, probably about 25 degrees too cool. The hot water at the tap is also 110, meaning the dishwasher, which has a built in water heater, isn't working. If my assessment of this is correct, can someone tell me what's involved in repairing the unit? Or should I scrap it and buy a new one?
Thank you.

Model 665.15899100

[JWWebster]

I hate dishwashers. The soap dispenser probably needs replacement. I have sold a lot of them over the years. Why not just dump the soap into the dishwasher tub? Water is constantly pumped from the tub to the dishes all during the wash cycle. Do you really NEED to have your dispenser do the job?

[Carbo]

The strange thing is, the soap dispenser is open, but the soap isn't being flushed out.  So I don't know what the heck is going on. 
I know the water isn't hot enough for the dishwasher to do its job, but I would think even cool water would wash the soap out of the dispenser.
I have a suspicion that Sears will soon be the beneficiary of my own personal stimulus plan. 

[RAH52]

Sounds to me like the spray arms aren't turning .That would explain the undissolved soap in the open dispenser  . maybe your filter is plugged or the small holes in the spray arms are blocked . I would clean the spray arms and use a delimer and delime the dishwasher before buying a new machine .

[JWWebster]

Yeah that ciculatory pump could be going out or full of food particles not allowing fer the propah flow of water up to the washer arms. Have ye tried removing the screen and giving it a good scrub?

[Carbo]

I checked the spray arms for blocked holes, but they all appear to be completely open and clean.  
What filter are you referring to?  I'll readily give it a look.

[RAH52]

I'm not familiar with this model but most d/w have a filter under the lower wash arm support . I would remove the lower arm and wash arm support or cover and see if there is a filter . If so clean it . If its plugged no water will get to the spray arms

[JWWebster]

You know how them commercials for maytag dishwasher are: The big guy puts a whole cake in the dishwasher and like magic the cake is all gone. Well that gives folks the impression that a dishwasher is a disposal. No need to scrape any dishes. I had a friend bring me his dishwasher full of shrimp shells can you imagine that?

[Carbo]

I guess the next step is to give that filter a look.  I'll let you what I find.  Thanks, gents.

[Carbo]

I tried removing the lower spray arm but I'll be damned if I know how.  It looks simple enough, but I can't budge the nut.    Any hints?

[Carbo]

Did some more kicking around today, including just running the unit through its normal load.
Unfortunately, same old, same old.  Soap dish opens fine, but the soap isn't being hit with water.  Looking closely, I suspect that the top sprayer arm isn't working because the top rack dishes seemed to be relatively dry and certainly not cleaned.
If this is correct, is this repairable?  Thank you.

[JWWebster]

I have never even seen this machine but their was a thread last week about this same thang. Could not get the dang bottom arm off. I know I saw it.

[Carbo]

JW, I don't think I need to tinker with the lower spray arm, after all.  See my post above.  The problem seems to be the upper arm.

[JWWebster]

Your water pressure is what the probo is. With the screen clogged the pump cannot get enough water up there to be effective.

[JWWebster]

The circulatory pump is compromised with a restricted water flow from a blocked food particle screen.