Saeco Exprelia Evo shows heating up message then restarts without any error message. This repeats every few seconds with an occasional refill water message in between.

The issue you are describing with your Saeco Exprelia Evo coffee machine, where it displays a "heating up" message and then restarts without any error message, could be caused by a few different issues. Here are a few things you can check:

1. Check the water tank: Make sure that the water tank is properly filled and that there are no blockages in the water supply line. If the water tank is empty or there is a blockage in the water supply line, the machine will not be able to heat up properly and will display a "refill water" message.
2. Check the brew group: Make sure that the brew group is properly seated and that there is no debris or blockages preventing the flow of water through the brew group. If the brew group is not properly seated or there is a blockage, the machine will not be able to heat up properly.
3. Check the heating element: Make sure that the heating element is functioning properly. If the heating element is not functioning properly, the machine will not be able to heat up.
4. Check the thermostat: Make sure that the thermostat is functioning properly. If the thermostat is not functioning properly, the machine will not be able to heat up properly.
5. Check the boiler pressure switch: Make sure that the boiler pressure switch is functioning properly. If the boiler pressure switch is not functioning properly, the machine will not be able to heat up.