Built in NEFF Dishwasher model S5456X1GB/12 not heating wate

[Simples]

My Neff's gone Naff!
First indication of there being anything wrong was that the short 30 minute program was still running after 90 minutes, and the time left to program end was incrementing, not decreasing.
On further inspection and test I discovered that the wash water is remaining cold throughout the wash cycle.
My diagnosis is that either the "Instantaneous water" heating element has expired, or that the main PCB has shuffled of it's mortal coil.
Now the questions...
How do I get to the offending parts (The dishwasher is built in below a granite worktop)
What resistance should I expect across the terminals of a healthy Instantaneous water heating element?
And is there anything else that I should look at?
Thanks for any suggestions posted.

In the meantime, Its Marigold's O'Clock!

 

[zipper]

When a heating fault occurs some machines just keep on washing into infinity. Yours is one of them & it is produced by Bosch/Siemens. The heater element should measure around 22 ohms at room temp. There is a combined NTC sensor/safety switch mounted on the side of the heater assembly, your fault could also lie there. If neither then it is likely to be a bad connection, broken wiring or a defective pcb. The NTC should measure around 48k ohms at 25C & show a decreasing tendency when warmed. To get enough access to measure the heater element resistance the right had side-plate has to be removed. It is an awkward job to change the instantaneous water heater should this be your problem. There is no removable bottom plate on your machine as such. You would have to take out the tank screws then wedge something between the tank & plastic base to give you enough room to work. Don't try to remove the base completely, you will have a devil of a job to get it all back together again. Be prepared for bruised knuckles & swear words if you have to change the heater. Good luck

 

[DrEvil]

I think I have a similar issue - model S5444X1GB/08 - c 5 years old. We've inherited it recently from old owners of the place.

Worked fine for first couple of weeks, then found a wash was still going the following morning. I opened it at that point and it was dry, but a film of salt or powder over everything. Tried the rinse and even that just kept going and going. Tried a rinse again and it ran through a rinse cycle this time and ended.

I then tried another cycle from scratch (no plates in it this time) and opened it after 10 mins and also after around 30 mins. Seems to be filling fine, circulating fine, and there was a little bit of steam, but the water that collected at the bottom of the dishwasher was luke warm to the touch and I thought it should be 65 degrees as that was the cycle it was set to.

Does this sound like a heating element on the way out? Or some kind of PCB issue? EIther are $$ to repair and given its age, I'm wondering if a new one is more cost efficient!

 

[zipper]

Worked fine for first couple of weeks, then found a wash was still going the following morning. I opened it at that point and it was dry

It can't still be washing if there is no water in there. I think you may be confusing a leak on the baseplate with a no-heat issue. Tip the machine forward & see if any water runs out (use towels) then try a re-start & see what happens.

 

[DrEvil]

But, to clarify my last paragraph, on rerunning it again (after a reset) the water was only luke warm - even 30 mins into the cycle. After around 2 hours it was still washing and I needed to go to sleep so I just stopped and reset it.

I should have more time tonight or tomorrow night so will try the tipping and update.

 

[zipper]

The first part of the cycle is cold rinse. Heating doesn't occur until maybe 20-25mins into the program. So if you opened the door at 10mins the water would be stone cold. It probably still isn't up to temp at 30mins either, hence only lukewarm water. A 65C program should take 106mins according to manufacturers data. I suppose you could have a wonky NTC sensor. But I have a distinct feeling that a leak may be causing your problem. Let us know what develops.

 

[DrEvil]

Bit of an update but unfortunately I haven't been able to find the time (or my security screw torx bits) to get the integrated dishwasher out and lean it to see if water comes out.

I did try a cycle at 50 degrees, whilst I was here and paying attention though the cycle, indeed it did warm the water at around 1 hour, I could get to a lower part of metal that was heated to the touch and probably at by the 2 hour mark it was draining (I could hear it through the sink), but it just wouldn't move onto the end cycle and steam point. So after around 3 hours I gave up and opened it- there was still a bit of water coming out of, but overall very little water in the machine. Put the reset on and it did a couple of final drains and stopped within a couple of minutes.

Will hopefully see about doing a lean test at the long weekend.

 

[DrEvil]

Further update - pulled the integrated diswasher out, tipped it back and forth (to virtually 20 degrees forward and 45 degrees back) and no water came out.

It was fairly light too which would suggest not too much water kicking around to me.

With hindsight I didn't disconnect the feed and drain pipes (only the mains), that wouldn't have made a difference would it?

So if its not the heater, and not this water/anti flood issue - any other suggestions for quick diagnosis?

edit/ ran a cycle and to my amazement it worked alright. I left it running overnight so I can't be sure exactly how long it took to run, but seemed to go ok. Will keep a close eye on it and update further if (and when!!) it goes grumpy on me again.