Heater not blowing hot air, code 024

Hello,

The heater can blow cold air for a few reasons.
First of all, it can be simply due to being low on coolant. One of the common causes is a faulty blend door actuator. The actuator can fail in the cold position and that will make the heater not work or blow hot air.
It can also be due to a stuck open thermostat, which will prevent the engine from reaching operating temperature and that will lead to cool air out of the vent instead of heat.

Here is a helpful guide that covers the typical issues:

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

Please let me know of any questions.
Thank you.