Diplomat ADP8902 dishwasher not progressing/finishing cycle

[akbmcf1]

Hi all,

Am hoping for some help with a fault on our Diplomat ADP 8902 slimline integrated dishwasher.

It's started running constantly, as though the cycle is not progressing or is not being told to turn off at the end. I've tried turning it off at the mains for a while (always worth a try!), but the problem persists.

It seems as though the rinse cycle is working as you'd expect, but not the wash cycles. Also, when you open the door, the water is not hot (this machine is cold-feed only).

At the suggestions of the good people over on the ukwhitegoods forum, I've checked the element and the thermostat in the door with the following results:

Element:

Checked the heater with the multimeter - it had continuity and measures 28ohms resistance which looks to be about right.

Thermostat:

I found the thermostat in the door panel. I've tested it the only two ways I know - for continuity and resistance. It doesn't have continuity, but then if it's acting as a switch (bearing in mind I'm a relative n00b to all this) then that doesn't necessarily indicate it's faulty, right?

So I set my DMM to resistance, and am getting an infinity reading (display reads 1) at room temperature and when I put the thermostat in boiling water. Would this indicate the 'stat is at fault? Or is it a case of just swapping it out with a new part and seeing if that cures the problem?

Many thanks in advance for your help.
Andrew

 

[Terox]

Normally the temperature monitoring thermostat/thermistor on dishwashers is stuck to the base of the cavity, underneath. This way it can take a consistent reading of the surface temperature at the bottom of the tank/cavity when there is water in the dishwasher.

If the one you are checking is in the door, it may very well be an overheat thermistor, possibly for checking overheat during the steam drying process.(100Deg C +)

I don't know this model/make so the above guess maybe wrong.

To give you some info.
Typical Dishwasher operation after selecting a program (Not gospel for every machine and differs from program to program

1) Drain cycle for a few seconds
2) Fill
3) Wash (cold water) more like a rinse
4) Drain
5) Fill
6) Soap dispenser opens
7) Heat cycle/wash
8) Drain
etc etc

The heating cycle normally starts when the soap dispenser flap opens. So if you aren't getting any heat, make sure the flap has opened, that way you know its at least got to that stage and should be heating.

Some dishwasher have a heating element not actually in the dishwasher cavity, but fitted into the wash pump flow or return pipes. if this is the case, then they normally require a certain level of water before the heating cycle can begin.

If your dishwasher is like this, then to check if it is this add additional water when the soap dispenser flap opens by opening the door and pouring some in

The water level should be at the level of the raised section in the base of the dishwasher, directly below where the soap dispenser is. If it's a lot less than that, then there lies your problem

If you can get the element to come on using this "cheat" then you are looking at a faulty pressure switch

Horrible things to work on aren't they