Will you still have heat if your heater core is bad?

Hello, yes, a leaking heater core is still carrying hot coolant -- so you could still have heat. You'd smell a ton of coolant in your interior if this is the case. Have you confirmed you have coolant getting inside the vehicle?

Symptoms of leaking heater core: 1- COOLANT loss - check coolant level. 2 - Immediate and blanketing fog on inside of windshield when defroster is turned on - can’t see through windshield. 3 - Sweet but foul smell of engine coolant emanating from interior of vehicle. 4 - Usually does not migrate to back floorboard.