When you turn it to heat it will send a burst of heat but then pushes cold air. What needs to be fixed?

If you hear a gurgling noise then your coolant is low. Fill it up. Additionally if after you have filled and still no heat then your the heater core is clogged. Heater core replacement is a whole day job. You have to drop the whole dash and steering column to access. Youtube has a real good video that shows you how to do this as well as acess the hidden screws and bolts. Before you think of replacing you can unclog heater core and flush with garden hose. Heater core is on the left side of engine on fire wall. Look for 2 small hoses going into firewall off engine. I had a bad heater core and believe me its a big job. I took my time and did it in 2 days. One day to remove then next day to install. And while you are at it replace the climate door. Its only about 10 bucks. Hope this helps.

Check your antifreeze coolant level, its the easiest thing to fix and would create intermittent heater.