Saturn Repair: heater problem - no heat, 2000 saturn sl1, mileage cars

Question
I have a 2000 Saturn SL1, heater blowing cold air.  Where should I start?  If by replacing the thermostat, then where is it (and is this a likely cause)?  thanks

Answer
Well depending on the mileage the thermostat needs to be changed that usually takes care of it. It is located. Under the AC compressor inside the lower hose at block housing. Not very difficult of a job. Also If that doesn't solve the problem you may need to flush out the heater core. Do this by removing the heater hoses and use a garden hose to flush out the heater core. It may be clogged this is common with high mileage cars. But usually. The thermostat fixes it.