If it appears that your Thermomix ® TM31 is heating too slowly, it could be that the contact pins on the underneath of the mixing bowl are not in good condition.
In this case, please check the contacts and clean them, if necessary, with a soft cloth.
Another explanation could be the use of multiple power sockets.
It’s then possible that there’s not enough power for your Thermomix ® appliance.
Preferably, you should plug your Thermomix ® TM31 into a single socket to enable a problem-free power supply to the appliance.