having trouble with no heat getting to cab

I have a 95 sonoma 2.2l truck, 2 wheel drive,anti freeze and the rads hot, hoses to the heater hot,but no heat to the cab, put in new thermostat,when
you first turn heater on there is heat, then it goes cold. any ideas what the problem may be. thanks pcote
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you might have trapped air in the engine.
change thermostat.
some cars have water cut off to help air in the summer. it might be stucked close. .
pcote wrote:

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1. Heater core is plugged up. 2. Air in the coolant lines or coolant level is low. 3. Temp control flap is malfunctioning.
Could be one or more of the above however the heater core is more than likely the prob.
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thanks for all your input about my heater problems, pcote..
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