heater problem

[bjl4776]

I recently started havin a problem with me heater, and even though it is summer i still need it on occasion due to a 1500 mile move north. When the car gets warmed up it blows great heat, for about 10-15 minutes and then after that it is just slightly warmer than just the fan running. It would be nice to find out whats wrong before i have to scrap ice off of my windshield

[JonE]

Does it blow strong and warm with dial on position 4 and heat turned up full?

[bjl4776]

Only for the 10-15 minutes, than after that its just barely warm, no matter what the temperature and fan are set on.

[JonE]

I'm no expert, but usually the thermostat condition might be suspect or the heater valve is faulty or getting the wrong signal. Hopefully someone with more experience can guide you better on this one. Good luck.