Miele T494C Dryer Possible Earth Leakage
- Thread starter Chook
- Start date
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Interesting, I've not seen a Miele with the M-Nr not present. Looking at your profile, this machine is not in the UK or an EU market?
I believe the instructions to get this into service mode are as follows:
1. Switch off machine, set programme dial to Finish
2. Close door
3. Press and hold start button
4. Switch on machine
5. As soon as start LED flashes release start button
6. Immediately press and release the start button three times, on the third time hold the button until the start LED flashes slowly. If this doesn't work, try steps again but press and release the start button a bit quicker.
Once in the service mode, using the programme selector dial, switch it to the Normal option. The Cool Air or Finish/Anti-crease LED will flash two times if this is set correctly. This should set the machine into component test mode.
Some stored machine faults can actually block this from being achieved successfully using the front panel service mode.
Pressing the start button at this point will initiate the component test. There are several steps to this as per the following table, if you press start button again, the machine will stop the current test and move onto the next. The Drying LED will flash the number of times corresponding to the test step, i.e. for test two Heating (R1), the LED will flash slowly two times.
Test 1: Drive/Fan motor (M5): Drum turns with reversing as follows: 10 s anticlockwise, 2.5 s pause, 10 s clockwise 2.5 s pause, etc.
Test 2: Heating (R1): Heating and drive activated as follows: 600 s in normal direction, 2.5 s pause, 10 s in opposite direction, 2.5 s pause, etc. The temperature sensors are monitored and any detected faults saved.
Test 3: Condensate pump (M13) activation (condenser dryer only): Condensate pump activated
Test 4: Residual moisture sensing circuit (B3/1), low resistance (continuity) check
Test 5: Residual moisture sensing circuit (B3/1), high resistance (isolation) check
Test 6: Buzzer: Buzzer activation: Vented dryer: Continuous; Condenser dryer: Intermittent
Test 7: LED test: All LEDs flash at 0.5 Hz.
Test 8: Heating relays: Heating (R1 + R2) and drive are activated as follows: 600 s anticlockwise, 2.5 s pause, 10 s clockwise, 2.5 s pause, etc. The temperature sensors are monitored and any detected faults saved.
If you can get the machine into this mode, does the RCD trip during any of the tests, particularly 1, 2 or 8?
I believe the instructions to get this into service mode are as follows:
1. Switch off machine, set programme dial to Finish
2. Close door
3. Press and hold start button
4. Switch on machine
5. As soon as start LED flashes release start button
6. Immediately press and release the start button three times, on the third time hold the button until the start LED flashes slowly. If this doesn't work, try steps again but press and release the start button a bit quicker.
Once in the service mode, using the programme selector dial, switch it to the Normal option. The Cool Air or Finish/Anti-crease LED will flash two times if this is set correctly. This should set the machine into component test mode.
Some stored machine faults can actually block this from being achieved successfully using the front panel service mode.
Pressing the start button at this point will initiate the component test. There are several steps to this as per the following table, if you press start button again, the machine will stop the current test and move onto the next. The Drying LED will flash the number of times corresponding to the test step, i.e. for test two Heating (R1), the LED will flash slowly two times.
Test 1: Drive/Fan motor (M5): Drum turns with reversing as follows: 10 s anticlockwise, 2.5 s pause, 10 s clockwise 2.5 s pause, etc.
Test 2: Heating (R1): Heating and drive activated as follows: 600 s in normal direction, 2.5 s pause, 10 s in opposite direction, 2.5 s pause, etc. The temperature sensors are monitored and any detected faults saved.
Test 3: Condensate pump (M13) activation (condenser dryer only): Condensate pump activated
Test 4: Residual moisture sensing circuit (B3/1), low resistance (continuity) check
Test 5: Residual moisture sensing circuit (B3/1), high resistance (isolation) check
Test 6: Buzzer: Buzzer activation: Vented dryer: Continuous; Condenser dryer: Intermittent
Test 7: LED test: All LEDs flash at 0.5 Hz.
Test 8: Heating relays: Heating (R1 + R2) and drive are activated as follows: 600 s anticlockwise, 2.5 s pause, 10 s clockwise, 2.5 s pause, etc. The temperature sensors are monitored and any detected faults saved.
If you can get the machine into this mode, does the RCD trip during any of the tests, particularly 1, 2 or 8?
Thanks very much Honj for putting all this together. This machine is in the land of “Downunder” (the controls are at the bottom of the machine ). I tried the initiation sequence several times but unfortunately it didn’t generate a flashing START LED. I recall seeing somewhere about holding the Start & Short buttons down which I tried. This resulted in the Drying LED flashing but I was unable to achieve anything else.
There are two symptoms for which I ponder might point to a specific part of the unit.
1. After selecting start in drying mode, the drum rotates clockwise (viewed from the front) for 1 minute, pauses, then rotates in the opposite direction, after a few seconds I can feel heated air (condenser unit removed), another 10 seconds after that the machine cuts out (RCD trips).
2. After selecting start in timer in cool air mode the RCD trips immediately
What I am curious about, in the modes described above at what point does the blower motor start?
Could it be the motor or associated relay that is is shorting or earthing.
Or could it be related to the sensors in the heat bank?
There are two symptoms for which I ponder might point to a specific part of the unit.
1. After selecting start in drying mode, the drum rotates clockwise (viewed from the front) for 1 minute, pauses, then rotates in the opposite direction, after a few seconds I can feel heated air (condenser unit removed), another 10 seconds after that the machine cuts out (RCD trips).
2. After selecting start in timer in cool air mode the RCD trips immediately
What I am curious about, in the modes described above at what point does the blower motor start?
Could it be the motor or associated relay that is is shorting or earthing.
Or could it be related to the sensors in the heat bank?
>>This machine is in the land of “Downunder” (the controls are at the bottom of the machine )
lol.
Since you get the flashing Drying LED when pressing Start and Short, Miele refers to this in the various service mode procedures as a Novo Basic model. Once in that mode, moving the programme selector dial from Finish to Cottons Extra Dry then pressing Start should initiate the drum motor component test - 10s anticlockwise, 1.5s pause, 10s clockwise.
If that works, repeat the procedure but switch the programme dial to Minimum Iron Normal will test the cooling fan, does the RCD trip?
Other test options here are:
Cottons Normal - 2kW heater with fan and heater
Cottons Hand Iron I - 1kW relay
Cottons Hand Iron II - Full (1kW + 2kW) heating with fan and drive
Woollens Hand Care - Fault codes (do any LEDs light during this test?)
>>What I am curious about, in the modes described above at what point does the blower motor start?
Unfortunately there isn't detailed information as to specific timings of when a component activates, just that for cool air mode programme it operates "cooling phase" for a while, reversing the drum and then goes into "anti crease phase", timings dependent on residual moisture measurements. No mention of any warming though, which would isolate the heaters from the diagnostics.
I think the fault is more likely to be caused by an insulation break down in one of the components and not the relays themselves, never say never though. In my brief experience these faults are caused by a heating element issue but the fact yours trips in cool air mode immediately suggests a problem elsewhere e.g. the fan motor.
The motor relays are all contained behind the control panel but the heater relay appears to be a separate unit located near to the door lock mechanism if that helps.
lol.
Since you get the flashing Drying LED when pressing Start and Short, Miele refers to this in the various service mode procedures as a Novo Basic model. Once in that mode, moving the programme selector dial from Finish to Cottons Extra Dry then pressing Start should initiate the drum motor component test - 10s anticlockwise, 1.5s pause, 10s clockwise.
If that works, repeat the procedure but switch the programme dial to Minimum Iron Normal will test the cooling fan, does the RCD trip?
Other test options here are:
Cottons Normal - 2kW heater with fan and heater
Cottons Hand Iron I - 1kW relay
Cottons Hand Iron II - Full (1kW + 2kW) heating with fan and drive
Woollens Hand Care - Fault codes (do any LEDs light during this test?)
>>What I am curious about, in the modes described above at what point does the blower motor start?
Unfortunately there isn't detailed information as to specific timings of when a component activates, just that for cool air mode programme it operates "cooling phase" for a while, reversing the drum and then goes into "anti crease phase", timings dependent on residual moisture measurements. No mention of any warming though, which would isolate the heaters from the diagnostics.
I think the fault is more likely to be caused by an insulation break down in one of the components and not the relays themselves, never say never though. In my brief experience these faults are caused by a heating element issue but the fact yours trips in cool air mode immediately suggests a problem elsewhere e.g. the fan motor.
The motor relays are all contained behind the control panel but the heater relay appears to be a separate unit located near to the door lock mechanism if that helps.
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Thank-you again Honj. I went through the test sequences several times. I could feel the heat through the condenser door so very confident the heater bank is OK (which when I removed & visually inspected it, the part looked AOK)
When I ran the cooling fan test (two times) the RCD tripped immediately.
I wonder if that test covers every section of the cooling fan circuit. I presume it has a relay. It looks like it maybe a bit of task to remove. I am also informed the cooling fans have synchronous motors so no brushes etc involved (could it be stuck?) I wonder if a few taps in the right spot might work?
When I ran the cooling fan test (two times) the RCD tripped immediately.
I wonder if that test covers every section of the cooling fan circuit. I presume it has a relay. It looks like it maybe a bit of task to remove. I am also informed the cooling fans have synchronous motors so no brushes etc involved (could it be stuck?) I wonder if a few taps in the right spot might work?
No probs. Firstly I would double check the wiring all the way from the fan to the board that it plugs in to, will be tricky but could easily be a broken wire.
The test mode will trigger the fan relay exactly the same way the cooling programme does, therefore the scope of this test includes the relay and the control circuit as far as I'm aware.
The part number for the fan according to Miele is 4754991, double check this against the one actually fitted. If you can get it out, an electrician with right equipment should be able to prove it is at fault relatively easily. Not a cheap part unfortunately - very likely to be consigned to the appliance recycling depot
.
BTW not sure about what the actual type of motor is, I guess if it was stuck it could have overheated and damaged the internal wiring thus causing a permanent short to ground.
The test mode will trigger the fan relay exactly the same way the cooling programme does, therefore the scope of this test includes the relay and the control circuit as far as I'm aware.
The part number for the fan according to Miele is 4754991, double check this against the one actually fitted. If you can get it out, an electrician with right equipment should be able to prove it is at fault relatively easily. Not a cheap part unfortunately - very likely to be consigned to the appliance recycling depot
.BTW not sure about what the actual type of motor is, I guess if it was stuck it could have overheated and damaged the internal wiring thus causing a permanent short to ground.
Disconnect the cooling fan, at the fan, and test again after insulating the ends.
Yep!
I have been thinking about why the RCD would trip @ 80 secs into the drying cycle and I think the reason is because the cooling fan is programmed to start at that point (either by time or temp) to start blowing cool air across the condenser collector plates. It didn’t trip on the heating test cycle as the cooling fan circuit would be isolated .
Is that logical?
Is that logical?
>>It didn’t trip on the heating test cycle as the cooling fan circuit would be isolated .
You mean it didn't trip on the heating only test cycle? If so, then yes the fan would have been isolated from that test.
I would follow Harry's advice and disconnect the fan and run the fan only test to see if it fails. I suspect you'll get a bunch of LEDs light up at end or during test if it doesn't trip the RCD to indicate the fan is open circuit. the only further diagnostics will require electrical testing using external equipment.
You mean it didn't trip on the heating only test cycle? If so, then yes the fan would have been isolated from that test.
I would follow Harry's advice and disconnect the fan and run the fan only test to see if it fails. I suspect you'll get a bunch of LEDs light up at end or during test if it doesn't trip the RCD to indicate the fan is open circuit. the only further diagnostics will require electrical testing using external equipment.
Where I wrote, is that logical ? I was referring to the cooling fan starting after 80 seconds (under normal conditions) into the drying cycle.
That service mode is invaluable in fault finding (thanks Honj). I hope the cooling fan is OK & the fault is a something like a relay. I have several Miele appliances (at my wife’s direction) and they are well constructed, how do I know? … because I have had to repair some … therein lies the quandary. My (wealthy) friend owned a Rolls Royce. He was in Spain at the time & a spring broke (I recall it was a door spring) he arranged for a replacement. On return to his mother’s soil he arranged to pay for the rather hefty invoice, upon which, he was advised that the invoice can’t be verified because RR (door) springs don’t break!
I don’t think Miele is going to advise me that their components don’t fail!
That service mode is invaluable in fault finding (thanks Honj). I hope the cooling fan is OK & the fault is a something like a relay. I have several Miele appliances (at my wife’s direction) and they are well constructed, how do I know? … because I have had to repair some … therein lies the quandary. My (wealthy) friend owned a Rolls Royce. He was in Spain at the time & a spring broke (I recall it was a door spring) he arranged for a replacement. On return to his mother’s soil he arranged to pay for the rather hefty invoice, upon which, he was advised that the invoice can’t be verified because RR (door) springs don’t break!
I don’t think Miele is going to advise me that their components don’t fail!
Yeah, what you wrote is logical re the fan starting at a set time into the normal programme. I'll always buy Miele because I like their approach to designing products with the kind of integrated fault finding features being discussed here.
I've definitely had a few faults with them over the years mind you, washing machine needed new dampers, tumble drier condensate pump got stuck on etc etc. All of which have been very easy to diagnose and repair. My only complaint is they don't necessarily make all this information accessible to joe-public.
Have you been able to run the fan test with it disconnected and wires isolated? That'll be the quickest way to reasonably prove its an issue with the fan itself.
I've definitely had a few faults with them over the years mind you, washing machine needed new dampers, tumble drier condensate pump got stuck on etc etc. All of which have been very easy to diagnose and repair. My only complaint is they don't necessarily make all this information accessible to joe-public.
Have you been able to run the fan test with it disconnected and wires isolated? That'll be the quickest way to reasonably prove its an issue with the fan itself.
Not yet Honj, I will keep you updated with my endeavour. What you raise, is an Interesting aspect of consumer law. There was a case in AUS a few years ago where the farmers challenged John Deere to service/repair their machinery. In the end, JD had to hand to provide the farmers (the owners of the machinery) with the access and information that was required to carry out the necessary work. This machinery is big $ (especially the broad average stuff, … thousands of acres). Miele appear to be very much a closed shop. It is very hard to extract any useful information from them. It would be interesting to see the outcome if they were challenged with a class action claim.
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