Never realized that it didn't have any heater?

Hello,

There are few reasons of why a heater can be non-functional.
It can be due to low coolant level, stuck open thermostat, faulty blend door actuator, bad heater core.

First make sure that the coolant level is correct. Low coolant will have limited or no flow thru the heater core and that will not allow the heater to blow hot air.

If the thermostat is failed at stuck open position, it will not allow the engine to warm up sufficiently and that will lead to poor heater performance.

The blend door actuator controls the hot or cold air flow. Many times, the actuator fails in cold side, which will lead to have no heat as the air door will be stuck on the cold side.

Take a look at this guide it covers the typical issues for no heater:

https://www.2carpros.com/articles/car-heater-not-working

I have attached diagrams for your reference.

Please let me know if you have any questions.
Thank you.