Why coolant not circulating?

Hi, my name is Devin. I am an auto repair expert with the Car Genius team here at RepairPal. I'm sorry to hear you're having trouble with your vehicle. If you've replaced the heater core, radiator, cap, thermostat, and water pump, and the coolant still isn't circulating, it could be due to several factors. There may be an air pocket trapped in the cooling system, preventing coolant flow. This can often happen after significant repairs and may require extensive system bleeding. If you still can't get the air bled from the system, you can try a vacuum bleed/refill tool. If you need more advice, have any other questions about your vehicle, or would like to get connected to a RepairPal Certified shop near you, we have you covered. Give us a call at 877-913-1554, and we will happily help you out!