miele dishwasher G 4225 "F02" code - temp. sensor open circuit

[lumpy_rutherford]

In the past week, my Miele G 4225 has started registering a "F02" code.  It appears to go through the whole wash cycle normally (including heating up the water), the fan turns on as it always has during the last 30 or so minutes of the cycle, and then at the very end, the drain pump turns on for several seconds (as always), but then it registers the "F02" code right after the pump & fan stop.  And the Intake/Drain light flashes.

I found a tech info manual for g1000/g2000 dishwashers, so I've been able to do the following. 

1. test the temp sensor with a multimeter (resistances were pretty close to what they should be according to the "NTC Sensor Resistance Values" table). 
2. The connector seemed to fit securely
3. Took apart the door to get to the PCB, took off all connectors, swabbed contacts with alcohol.  Since all the wires are bundled together from underneath the unit to the PCB, it would've been EXTREMELY hard to follow the wires the whole way to test them for continuity.  All the wires looked okay, though.
4. Followed instructions to reset settings to factory defaults (then turned off Rinse Aid light - I don't use rinse aid since that reportedly wrecks beer head retention)
5.  Followed the G2420/2430 instructions to delete the fault memory
6. Followed the G2420/2430 instructions to go through the "component test(s)".  Nothing of interest happened.

The G2420/2430 instructions also helped me see that:

1. 189 Operating Hours have been logged
2. Software Version 2655 is loaded

Other Info:

1. Dishwasher is only around 2 years old
2. Issue is intermittent.  It ran without failure codes after I deleted the fault memory & ran through the component tests.  But it failed the NEXT time I ran a load.  Dishes seem as clean as always, and water definitely heats up.
3. When the dishwasher was about a year old, the outlet it was plugged into almost caught fire (I luckily smelled a burning smell and turned it off).  I assumed this was because the hot wire didn't seem to be securely fastened to the outlet screw when I took apart the singed outlet to replace it.  We bought an old house with all sorts of wacky surprises/issues...  Since then, I noticed that the AC plug always gets warm during the wash cycle, when I assume the heater is on.  It's not warm at the beginning of the cycle, or the end.  Also supporting my theory that the heating element sucks a lot of current is that it seemed to get a lot hotter when the dishwasher was connected to cold water, as opposed to hot water.
4. Can't imagine this has anything to do with anything, but until we re-do our kitchen with new cabinets, I have this hooked up to the kitchen faucet via an attachment salvaged from a portable dishwasher. It's also enclosed in the portable dishwasher's steel cabinet. The drain hose hasn't been extended - just have a 8" galvanized pipe attached to the end so that it doesn't flop off the kitchen sink/drain board.

From some other posts from this extremely useful site, I've gathered that not only are the folks who post here extremely helpful, but Miele support is too. 

But since it's Sunday, I thought I'd post here to see if anyone here has any ideas for me before I call 800-999-1360 tomorrow.

Thanks, and I'm so glad I found this site!

 

 

[lumpy_rutherford]

After searching for _everything_ coming up for "miele", I found this thread:  http://appliantology.org/topic/52030-miele-dishwasher-g2427scvi/#comment-310571

This pointed me towards the wiring diagram I received _with_ the dishwasher.  Not sure if this diagram was in the G1000/2000 tech. info PDF and I missed it, but at least I now know to do my resistance tests on pins 7 & 8 on ST44.

Will be doing some more tests now.

 

[lumpy_rutherford]

Crap.  8.18K measured at pins 7 & 8 on ST44 @ 95 degrees (right where it should be).  Hope it's not "the electronic".

Maybe caused by high temp -> lower "drying" temp -> jolt from drain pump?  As mentioned above, I've only seen "F02" register at the very end of the cycle.  It's occurred to me that I'd have no idea whether some of the F02s could've registered earlier in the cycle those times I wasn't watching the whole cycle start -> finish.

Some UK site sells a Miele temp sensor that looks mine for around 13 pounds, so I'm assuming I'd have to pay around $20 to find out if mine is intermittent.  If not, then I guess I'll be trying the freeze spray/hairdryer technique to see if there's some thermal intermittent on the electronic.

Anything else I could be checking?

 

[lumpy_rutherford]

I just got off the phone with Miele.  The technician I spoke with agreed that I tested the sensor properly, but said he couldn't advise me of any other diagnostics "due to liability issues".  As I can't seem to ever hire anyone who does a job right (car, plumbining, electric, roof, chimney, windows, fence, insulation, house inspector, energy assessment, etc...)  It looks like I'm out of luck, unless some sort of miracle happens.

[douwjo]

Dear lumpy,

Did you manage to fix the machine? I'm currently experiencing exactly the same issue. (f02 error but with heating during washing cycle).

Your help is much appreciated.

[lumpy_rutherford]

Quck answer: "not yet".

I called support, but they wouldn't help me when they found out I was "just" a consumer, so I've just been dealing with the error code and gritting my teeth.  At least it still SEEMED to work.

More recently, I started getting f51 errors, which means the machine won't even attempt to wash.

I did some more reading & research, and cleaning a bunch of crud out of the heater pressure switch (with oxiclean), and scraping some of the carbon off the contacts of the heater relay worked for a while, but I ordered new parts (from Miele) just in case.  I received the heater pressure switch, and haven't gotten any more f51 errors.

The heater relay was back ordered, and I've been too busy after it finally arrived to put it in.  I'm hoping that it might fix the f02 errors, and I'll post the results in the next few weeks when I get a chance to take everything apart again (for about the 100th time - after the f51 troubleshooting marathons).

I'm not too thrilled that I spent 3X more for this dishwasher (than the other options I was considering), and it started having issues with it right after the warranty expired.  Especially because it's supposed reliability is what made me buy it in the first place.

 

 

[MoTeD]

Contact Miele about purchasing an extended warranty. Most of the time the manufacturer will work with you about it. 

 

[chrismcc]

any updates, I am experiencing the same problem with F02 fault,  resistance at the NTC temperature sensor is within the specs of At 68°F (20°C), the temperature sensor resistance is approximately 14.9kΩ (± 750Ω); at 77°F (25°C), approximately 12kΩ .  about to call Miele tomorrow but last time I called they were not very helpful.  I too don't trust any of the idiots that do appliance repairs, they are all a bunch of thieves.   it will cost me over have the value of the dishwasher but the time I actually get it fixed.  

[lumpy_rutherford]

I finally got a chance to replace the relay today and it didn't get rid of the F02 error. 

I reset the memory before doing a load, and set my expectations to low. 

I guess I'll keep using the p.o.s. the way it is.

[MoTeD]

On 10/26/2017 at 9:08 PM, chrismcc said:

 I too don't trust any of the idiots that do appliance repairs, they are all a bunch of thieves.   it will cost me over have the value of the dishwasher but the time I actually get it fixed.  

Too bad you feel this way about our industry. As far as cost goes, Miele parts are expensive and there is nothing us technicians can do about that. Owning a Miele is like owning a Mercedes, expensive to buy and expensive to repair. 

[LI-NY Tech]

F02 is an NTC thermister error. Typically they will test ok initially but will fail as the temp rises.  Verify wiring is on between NTC and power electronic. If so replace NTC and reseat connector at power electronic.  Then clear the fault codes from the memory. 

Small possibility of a problem with the heater or power electronic though those are unlikely. 

Edited November 9, 2017 by LI-NY Tech

[lumpy_rutherford]

Thanks David, I'm hoping to try this out during my holiday break.

[lumpy_rutherford]

David,

You're the best!  I hemmed and hawed the whole time about replacing the thermister since it seemed to test okay, but your post nudged me towards gambling on ordering  a new one.  I put it in last night, and FINALLY no F02! 

Thanks again!

 

[LI-NY Tech]

 

[chrismcc]

What is the part number for that sensor?  I got a guy from a appliance repair company here and he has no clue what he is doing.  After reading the posts from the last month i am going to try what David suggests.

[chrismcc]

I meant to add my model number is g 5605,  the guy recommended the thermostat sensor but also the flow meter.  Another symptom seems to be the machine is not filling with enough water .  Perhaps the water level is the issue for the f2 fault, or perhaps it has something to do with the rince cycle to it is not calling for enough water because of some temp sensor issue.    In any event, I am frustrated to no end, I paid 100 bucks already and new her wants another 407 bucks.  this is ridiculous.  $507 in labor to replace a part that is 20 bucks.  I need some help here if anyone can assist. if anyone can help me out to ensure I at least order the correct part numbers I would are forever grateful!!]

thanks!!

chris

[lumpy_rutherford]

I'd call 1-800-999-1360, or whatever number is on your owners manual to order parts - which is what I did.  The temp. sensor was $16 plus approx. $10 for S&H.  My item # was 07017320, but I have no idea whether my model uses the exact same parts as yours.  They'll ask you for your model number, and the name of the part (i.e. "temperature sensor); you don't need the actual part number.  They warn you that there's no guarantee on parts not put in by authorized service people. 

I mentioned above having to clean a bunch of crud out of parts, which I wonder may have more easily accumulated from the defective sensor shutting the heat off before it got hot enough to dissolve things.  I know Oxyclean dissolves that junk, but it also foams a lot, and I'm under the impression that a lot of foam isn't good for certain dishwasher parts.  And too bad bleach would wreck the stainless steel.

If you're not comfortable doing this yourself, I wonder if MoTeD's approach to calling  Miele and asking them to help you out might help.  If they pull through,  post everywhere what a great company they are, and how they don't leave their customers high & dry, etc...  If their customer service stinks, post that everywhere (if you have nothing better to do, I guess).

Sometimes I've had good luck with companies standing behind their products (recently, Allen Edmonds was excellent to me), and others that I'll NEVER buy from again (Nissan).  I wasn't thrilled that Miele support wouldn't help me over the phone, but maybe they've been burned by liability lawsuits or something.  I'm really lucky douwjo brought this thread back to life and David stumbled onto it.  I know it's lame, but even though it's been a week already,  it STILL makes me happy when I think about not having to shop for a new dishwasher.  I hope things work out for you too.

[Blondgirl88]

Thanks to all of you I am pretty sure that my F02 fault code on my Miele Dishwasher G 4225 is because of the temperature sensor! Thank you for that, my question is now, once I receive the replacement part, how would I remove the old and install the new sensor? There is no instructions anywhere found on the internet or You Tube. Thank You!

[PIX]

I had the same problem with my Miele machine, unplugged the plug next to the temperature sensor, tightened the contacts with pliers, cleaned it well and lubricated it with contact cleaning and lubricating sprays, reassembled and the error disappeared.