Heater intermittently not blowing hot air

Hi,

If the temperature is changing from hot to cold, the first thing I recommend is to check the engine coolant level. When the engine is cold, open the radiator and see if it is low there as well as the overflow reservoir.

If that is full, then there is likely an issue with the blend air door or door actuator. That is the component that determines the air temperature entering the vehicle. Take a look through this link. It explains in general how to replace one. I'm not recommending this be done at this point but want you to be familiar with the component.

https://www.2carpros.com/articles/replace-blend-door-motor

Let me know if you notice any clicking from under the dash.

I will watch for your reply.

Take care,

Joe