Heat not working

Also..check your actual lines...make sure they are connected and not bypassed...a lot of people bypass the heater core....if your the only owner and have never done this..then thats not it....check and make sure your thermostat is opening..open the cap to your radiator and watch it as the motor warms up..youll see the water swirl when the thermostat opens if you dont see that and the motor gets hot...replace it....check the vent doors under the dash...make sure they are opening properly...im assuming its an electrical panel like my truck to switch between cold and warm...if the door isnt opening properly, youll only get the air the blower moves.

Potential easy solution; check whether there is a vacuum operated valve in the heater supply or return lines. My old v8 '84? Malibu had one. It kept coolant from circulating through the heater until the motor warmed up; helps warm the engine quicker; BUT it was stuck closed and I had no heat. Rather than purchase a new one or mess wqith the vacuum lines, my solution was to use a piece of wire (nylon zip tie might work also) to hold the thing in the open position. So the motor takes a minute longer to warm up. Else might be air embolism in the line, which could indicate combustion leak or insufficient purging of air from the system after you changed the t-stat. Good luck.