ᐅ Mechanical ventilation system with heat recovery – indoor temperature too high

My house has a mechanical ventilation system with heat recovery from the company Zehnder. On hot days, I set the temperature controller of the ComfoAir 350 to minimum, but I still can't get the room temperature below 23°C (73°F). The heat exchanger is already turned off. What can I do?

Contact the manufacturer and ask Zehnder about options to lower the temperature further.