Miele WT2789i technical fault 4 appeared but later stopped

Hi,

We have a Miele washer dryer (WT2789i) which last Thursday started coming up with technical fault 4 (required to contact support) when any type of drying cycle was selected. However today (first use since then, although I also checked it on Friday) it managed to successfully complete a 30 minute warm air cycle. I’ll try it again tomorrow to see if it is still working without the fault.

I called Miele to arrange a service visit and they said technical fault 4 means “the temperature sensor is open circuited within the washer dryer air path”, and the exact issue can only be found during the visit.

Is it normal for a fault like this to suddenly disappear? And is this kind of thing (although difficult to know exactly what it is) a serious issue, as I am wondering if I should cancel the service visit if it’s no longer happening for now. I’m concerned that they won’t be able to find a problem at the scheduled service visit and that we’d have to pay for another service down the line if the issue cropped up again.

Thank you in advance for your help, really appreciate it.