So, you’ve cleaned the filters. You still get “clean out airways”?

Do you have a Miele Condensing tumble dryer that keeps stopping with a “clean out airways” error? Have you cleaned out the three filters around the door of the drum, as per the manual? Have you washed and cleaned the internal plinth filter as per the manual? Does the clean out airways error still haunt you with its beeping and cancelled drying cycles?

The fix is inside the back of the dryer

Happily there is another cause of this error that is not mentioned in the manual, but is nonetheless easy to fix. On the back of the dryer there is a heater unit consisting of a small metal box with two open ends. This is accessed by removing the panel on the back of the dryer. This is held in with torx bolts. These should not scare you, its just a bolt. But you need a torx screwdriver bit, available most decent hardware stores. Then two more screws holding this metal box (the heater element) in place. Of course, first you must fully disconnected the dryer from the power.

Inside the metal box, you will see a series of wire heater coils. If you see these are clogged with lint, even if it dossnt look too much, this is the likely cause of the clean out airways error. It’s why you’re here, because nothing else has worked.

Carefully remove any material clogging those heat coils. I did it with a long screwdriver, gently prising the lint from the elements then blowing it out. Did I say be careful and extremely gentle? Imagine you’re picking food off someones eyelid, or retrieving something from inside their ear and you’ll have the right idea. Take your time and be very patient and gentle because if you break one of the coils, your wallet will be in for quite a shock. Be sure to clean out all of the material, particularly that closer to the temperature sensor (see below).

But why?

If you look closely at the metal box, it also contains two sensors. One is a temperature sensor and the other a thermostat or cutout. Most likely what happens is the heat coils radiate more heat than anticipated due to the lint build up, and the temperature sensor detects that and assumes there is insufficient airflow, which isn’t quite true but the heater is certainly getting too hot – pretty much the same thing.

That in turn,  causes the clean out airways error.

Alternately maybe the lint restricts the airflow sufficiently to cause the sensor to detect overheating. It would have to be pretty clogged for that. Mine was not at all bad, but still sufficient to cause the error. Either way, this is the likely root cause of the problem if you have checked everything else. 

Additional thoughts

While you’re there, if you are electrically minded, you can check the resistance of the temperature sensor and observe that it decreases when you put your fingers on it for 30 seconds or so.

While not conclusive, this does indicate the sensor is most likely working.

You can also check the thermostat, which should be a short circuit.

Because there is not much else to go wrong, these checks give you peace of mind that you are on the right track and should encourage you to clean the heater elements thoroughly. Or you could just do the meticulous cleaning and skip the checks. Its likely you’ve found the right solution anyway.

I have also seen reports of people calling out a technician who replaced some part that looked faulty. That’s possible, but also consider if the technician just performs the process I’ve outlined here and charges you. You likely would be less happy than knowing you have a shiny new part inside.

The problem with that is she probably wont highlight the importance of cleaning the filters every cycle to avoid a repeat of the same problem. And it will repeat if you don’t do that. Even if she did warn you, why change what you’re doing now (not cleaning the filters often enough)? It was a failed part, you think. Not a maintenance problem.

And that’s it.

Having done all of the above, reassembly is the reverse of assembly whereafter you can likely resume error free tumble drying.

It appears to me that when the filters are blocked the lint quickly finds its way to the heater coils. After having to repeat this process after cleaning the filters every few cycles, I now clean the filters before every single use and the Miele “clean out airways” problem has not resurfaced.

I can take no responsibility for anything you do to yourself or your dryer. The above is simply a record of how I spent an hour one afternoon to fix my Miele condenser tumble dryer. I wish you clean airways.