2000 Chevy Astro

Hi:
Make sure the coolant system is full. Next, is the engine warming to operating temp? If not, replace the thermostat. If it is, we need to check the heater core. There are two heater hoses that go through the firewall. THey are around 1/2 inch hoses. After you find them, allow the car to heat up to operating temp with the heater control on hot. Feel the hoses. One should be very hot, and the other should be just slightly cooler. Let me know what you find so I can further advise you.

NOTE: The heater hoses can be very hot, up to 200 degrees. Make sure you don't get burnt.

Joe