Set Appliance State:

WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Enter the service/installer mode by pressing and holding the tap and radiator buttons simultaneously for 3 seconds, then select:
"Settings" > "Limit values" > Max DHW Temp"
Is the maximum DHW temperature set to a high enough maximum for the flow rate and temperature requirements?
Note:
The default maximum is 60°C but it may have been reduced.