Nissan Repair: Heater, 2002 nissan altima, nissan altima

Question
I have a 2002 Nissan Altima.  When the engine is idle, there isn't any heat coming from the vents, just cool air.  When we push on the gas pedal, the heat starts coming out.  I have read the past questions and answers and you said something about flushing the heater core.  Does this sound like the same situation, or something different?  If I do need to backflush, which hose do I insert my garden hose into to flush it out?  I am very car illiterate and need answers given back to me like I was in 4th grade.  Thanks for your time and look forward to your answer!!
Neil

Answer
Neil,

Since the car is a 2002 I would say check to see if the car works at operating temperature.  If the temperature is normal you could check to see if the heater core is plugged by grasping each hose the goes to the firewall from teh engine.  One should be hot and the other just warm.  If the warm hose if cold then that is the hose you want to remove and backflush.  You will have to remove the other hose to allow the debris out.  But, I think you just have a defective thermostat.