How to troubleshoot the lack of heat in an Audi A2?

I recently noticed that my Audi A2 is not producing enough heat when I turn on the heater. The temperature gauge is normal and the air conditioning works fine. What could be the possible causes for this issue?

First, check the coolant level in your car. If it's low, it could be causing the lack of heat. Additionally, check for any leaks in the cooling system.

Another possible reason could be a faulty thermostat. If it's stuck open, it won't allow the engine to reach its normal operating temperature, resulting in no heat for the heater.

You may also want to check the blend door actuator. This component controls the direction of the air flow and if it's not functioning properly, it could result in a lack of heat.