Miele [Demo mode]what it means

Miele publish this as a setting rather than a fault, and unlike most manufacturers they publish the exact keypress to get out of it. Their text: the function "enables the microwave oven to be demonstrated in showrooms without heating up", you should not activate it for domestic use, and if you switch the appliance on while it is active "the message Demo mode appears in the display" and "the appliance does not heat up". It lives in the ordinary Settings menu, under Showroom programme: choose Demo mode, Off, and "touch OK for at least 4 seconds to deactivate demo mode"; the same route with On switches it on, and Miele add that afterwards "the microwave oven is fully functional again".

Why a manufacturer builds this is straightforward once you picture a showroom. A retailer needs an appliance that lights up, accepts presses, counts down and demonstrates its menu structure, on a display stand where nobody wants a working microwave. So there is a state in which every visible part of the appliance behaves normally and the only thing disabled is the part that generates power. The problem is what that looks like in a kitchen. The display lights, the menus work, the timer counts down, the programme finishes and announces itself, and the food is cold. That is indistinguishable from a failed magnetron, which is the most expensive repair a microwave has, and the difference is a four-second keypress.

Two situations make it worth checking. An ex-display or clearance appliance can arrive in the mode it was demonstrated in, in which case it has never heated since you owned it. And because the setting sits in the same menu as the clock and the buzzer volume, it can be switched on later by somebody exploring the settings — which is why an appliance that has worked for years can stop heating without anything having broken. It is not a button held from the normal display, so wiping the fascia will not set it; and Miele say that "modifications to settings are not affected by a power cut", so unplugging the appliance will not clear it either.

1. 1

   Confirm the symptom. Put a mug of water in, run it for a minute at full power, and check whether it is any warmer. The case this page covers is an appliance that behaves perfectly and heats nothing.

2. 2

   Switch the appliance on and read the display carefully. Miele put the words Demo mode there, so this one announces itself if you look.

3. 3

   Press the settings button, select Settings and confirm with OK, then Showroom programme, then Demo mode, and choose Off. Touch OK and hold it for at least four seconds. That is Miele’s published deactivation, and the same route with On is how it was switched on.

4. 4

   Test with water again. Miele say the appliance is fully functional afterwards, so it should heat immediately.

5. 5

   If the message is not on the display and the appliance still will not heat, this is not the fault and it needs an engineer rather than another keypress.