Miele G5600 "Futura" Dishwasher Error Code F-24

[rp2813]

Oh What a Relief It Is!

The relay arrived this afternoon and the machine is back up and running.  It's been 20-30 minutes since I started a normal wash cycle with a full load, and the detergent dispenser just popped open.  I'm feeling pretty good about the machine running all the way through.  I've only pushed it back into its opening about half way and still need to pull it back out and put the bottom panel back on.  I'll do that before I run the next batch of dishes and other items that have been backing up.  I really do hate hand-washing dishes!

 

Thanks for all of the time, effort and advice that has been contributed by everyone.  I'm glad it turned out to be the easiest of the potentially necessary repairs.

 

[rp2813]

False Alarm

The machine cut out and displayed F24 around the same point in the cycle as it did the first time.  This was sometime during the main wash because I never heard it drain again, but it's fairly quiet, I was in another room, and after taking a look inside, the tub isn't full of water.  It was definitely hot inside, so the heating system is working.

 

I suppose the pressure switch is the next component to check.  Maybe it will be easier to locate a new one, as I wouldn't trust a used one.

 

 

[henene4]

Given the machine supposedly runs the F24 check routine after drains start, it would make sense it ran a main wash.

I am still less convinced it is the pressure switch, but what do I know from here on out.

Make sure you take care to follow the instructions in the service manual for the pressure switch replacement, especially taking care about the wash pump.

Don't know how good your multimeter is, but check through the F24 chapter in the service manual aswell.

 

[me]

The F24 section of the manual does mention to check for resistance below a value of 10 megaohms (10MΩ) between the sensing lines on ST5 plug to the controller, although apparently the manual has got the plug number wrong according to some comments I saw, which said there was a circuit diagram printed inside somewhere. While the listed causes doesn't include a leaking pressure sensor, that would indicate it could cause that error too. I suspect a partial short to earth to one of those lines might do too.

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"Cause:

Fault in the plug on the output side of the heater relay.Contamination or corrosion on the plug of the heater wiring harness can cause a bridge between contacts, which can reduce the transfer resistance below a value of 10 megaohms (10MΩ).

Remedy:1. Disconnect the machine from the power supply.2. Disconnect plug ST5 from the electronic.3. Measure the resistance between the lines of the electronic for heater pressure switch B1/13 (pins 12 and 22 on plug ST5).4. If the measured resistance value is smaller than 10 megaohms (10MΩ),then the heater partial wiring harness must be replaced"

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If the replacement part was a used relay, then it is unfortunately still possible that it still is a heater relay fault, the contacts are only likely to weld when the element is powered, trigging the error after the element is turned off.

No idea if it is typical for dishwashers, but that dishwasher seems a weird design to me, after it does a drain for a while, it apparently has to turn the heater relay on and run the wash pump for a few seconds to check if all the water has drained out using the same two inputs, presumably the element doesn't come on because as long as some water has drained out only one of the two switches in the pressure sensor would turn on.

 

[henene4]

Those routines don't check for proper draining.

EU DWs have A LOT of redundancy and a lot of self check routines.
Ever since there have been a few cases of fires in DWs due to bad safety design, and with European design standards being VERY strict for appliances, having such self checks is just cheap insurance.

After each drain step it does check the water level via the pressure switch and the recirculation pump.
Only if that test confirms a drain, it continues the self check routine.

The pressure switch function is validated once at the start of the cycle.
All tests afterwards rely on that confirmation to be correct.
That test in it self relies on the assumption any significant water level in the machine before start is noticed by the user.

The test for the relay then relies on a working pressure switch and no creeping current.
Given that a value over 10 mega ohm is required, the electronic appears to be REALLY sensitive on those sensing inputs.

All of that is just to make sure the heater NEVER runs without water.
Even if that means some machines to be scrapped earlier than possible, it's better than thr reputation loss of a house fire.

BSH DWs don't use any real pressure sensors and only rely on drain pump and wash pump feedback for water presence sensing and thus safe heater operation.

That's why the wash pump errors on those happen WAY before the pump is actually unusably worn out.
Keeping big safety margins there means that any wash pump that could remotely sense water presence wrongly would throw error codes WAY before.

Difference is: On the Miele, it could be several components that could cause that issue.
On a Bosch, it's only one part. That part is designed to be as low cost as possible.

That huge safety thing in EU DWs is also why basically ALL DWs have float switches and a closed bottom pan.

Given we have HUGE amounts of dense flats in buildings, and DWs are always in kitchens, and YOU pay for ALL the damage a broken appliance could to ALL flats in a building, it's just way cheaper on the whole to make DWs uber safe against leaking and fire.

 

[rp2813]

Ixnay on the Itchsway

Yeah, all of that electro-jargon is over my head, and the mention of wrong info in the manual was enough to make me decide to cut the crap and make a service call.  The relay was as far down the rabbit hole as I felt comfortable going.

 

I'll circle back to this thread to share the findings and results from the technician visit.

 

[richnz]

Have a look at where the cable joins the main PCB

A long time ago I had a Miele dishwasher that was corroded where the pressure switch joined the main PCB.

It has 4 wires, 2 go to the pressure switch and 2 go to the heater relay.

Richard

 

[combo52]

Dishwasher heating elements

This is one of the reasons why domestic dishwasher still put the heating element in the bottom of the tub, it’s a lot safer to have the heating element in an exposed application, where it will not start a fire rather than putting it inside a plastic pump housing.

hi Ralph, have you looked into changing this pressure sensor it might be quite easy, although it is pretty tight under there you may have to pull the dishwasher out to access it. I’ve changed a couple of main pump motors in Miele DWs and it’s not too awful other than having to pull the machine from it’s installed position.

John

 

[rp2813]

Hey John,

 

Yes, the machine has been extracted since I started investigating the problem.  It has to be placed on its side in order to access the relay.  I only pushed it partially back into place to do a test run after replacing the relay. 

 

I called an authorized Miele repair service today -- no thanks at all to Miele's poorly designed customer service web site.  They are bent on making it next to impossible to find any sort of assistance with problems, sending the user in circles or to dead ends, and I am done with them in that regard.  I used Google to locate an authorized Miele repair service, found one with good reviews, and they seem to focus on dishwashers.  I have an appointment for a week from today.  

 

Since I've already paid for an overpriced relay that didn't resolve the trouble, I think it makes sense to stop throwing money at this issue when there's no telling whether another overpriced component will rectify the problem.  I'll leave it to the experts, and John, I know I'm preaching to the choir with that decision! 

 

Assuming the machine can be successfully repaired, I'll use it until something else goes wrong.  As much as I love this dishwasher, I won't pursue repairs again.  I'll find myself a nice Whirlpool/KA that offers straight-forward support, repair service and access to parts.  Miele has soured me on ever buying another foreign brand major appliance.

 

[rp2813]

The repair guy (Nash) just left.  Super nice and we might even be playing on the same team. 

 

He got on the phone with Miele tech support and went through a lot of diagnostics, pushing various buttons, watching for display info and checking functions.  He's fairly certain it's the pressure switch, but he's ordering another heater relay just in case the one I got from eBay is faulty.  There's a chance it could be the inlet valve, but enough water is entering the machine and the heater is definitely working because after a few minutes of making it run, steam escaped when he opened the door to check water temperature.

 

I don't know when he'll be back, but he's competent, he's interested in understanding machines and getting to the bottom of things, he likes to talk appliances, and likes what he does.  He even checked the OTR GE microwave and replaced a bad fuse -- in exchange for some huge fresh picked lemons my neighbor dropped off while he was here.

 

I'll return with a full report after his next visit.

 

P.S.

 

The Miele tech was on speaker and said the correct way to work on these dishwashers is to turn them on their left side (when facing the front of the machine).  Nash said he puts them upside down.  If you put them on their right side, there's a chance for any remaining water to get into some electrical components.  Luckily for me, I made sure all water was out of the machine and stuffed towels into the sump just in case, because the video I watched for replacing the relay showed the guy laying it on its right side.

 

[rp2813]

Success!

Nash returned today with a new heater relay and pressure switch.  The machine completed a "Normal" cycle without any trouble.  He also fastened the machine into place from the top with Miele screws rather than from the sides with grabber screws, which is how my plumber installed it when we moved in almost five years ago.  It was not easy to remove the grabbers and I'm glad to have the machine is properly secured. 

 

I hope this will be it for a while, but if any other appliance should require repair in the future that's beyond my capabilities to fix, I'll be calling Nash.  He's not only a fine looking man from Azerbaijan with thick black hair and beard but he's also very kind and sociable, and loves his work.  Eye candy is a bonus that the majority of us here can really appreciate.  I wish that man all of the success in the world.  He's very deserving and is managing to make a go of it in the most expensive area in the country.