No heat

Hello my name is Dave.

It sounds like there is a possibility that you have an air pocket in your cooling system. This is especially likely with a dual heater core system such as yours. The symptoms you have described really sounds like low coolant which air pockets could cause. I have attached a link for our tutorial for flushing and filling the cooling system. I would recommend flushing the system as added assurance, however I would strongly recommend following the fill procedure at the end:

https://www.2carpros.com/articles/coolant-flush-and-refill-all-cars