My car overheated. Replaced the thermostat and fan Now after finding a water leak and repaired it my heater blows cold

What is your question?

After replacing thermostat and fan we noticed the heater when turned on and car running there was no heat. Blew cold air only After adding water the heat came back on but then car overheated again We added a leak fixer and the car doesn't overheat but no heat with heater going and low air flow

How long has your 2006 Chevrolet HHR had this problem?

Since replacing thermostat