Car heater not working this problem is faced by many other users too.
Its quite possible that thermostat is faulty or heater core is plugged or radiator is clogged,or heater hoses are worn out or clogged,or the coolant is low or leaking.
There are many possibilities that can cause this problems.
You need to troubleshoot the problem.
First you try is confirm that heater core is not clogged.To confirm this
First warm up the car and turn on the heat.Then touch the 2 hoses going through the firewall to the heater core.
If one is hot and the other is not.You have a clogged heater core.
This valve is located under the hood.It opens and closes the valve which gives you heat.
For car AC related and Heater related solutions. You can refer the options mentioned below:---
Car AC Blows Warm Air ?
How to test AUTO AC pressure?
AUTO Air Conditioning Troubleshooting?
AUTO A/C COOLING PROBLEM?
Fixing refrigerant leak?
How to locate Car AC Refrigerant leak?
CAR AC INTERMITTENT COOLING?
What causes INTERMITTENT COOLING on Car AC system?
Car AC making Noise?
BAD ODOR ON CAR AIR CONDITIONER?
How to Recharge Car's Air Conditioner
http://repairhelpcenter.blogspot.com/2011/10/how-to-recharge-cars-air-conditioner.html
Its quite possible that thermostat is faulty or heater core is plugged or radiator is clogged,or heater hoses are worn out or clogged,or the coolant is low or leaking.
There are many possibilities that can cause this problems.
You need to troubleshoot the problem.
First you try is confirm that heater core is not clogged.To confirm this
First warm up the car and turn on the heat.Then touch the 2 hoses going through the firewall to the heater core.
If one is hot and the other is not.You have a clogged heater core.
Next you check is radiator,if its clogged with rust/curd /dirt layer collected in it then you will notice this no heat or low heat problems.Get the radiator inspected and flushed.
On some model vehicles there is a valve that opens and close,this controls heat.This valve is called heat control valve.This valve is located under the hood.It opens and closes the valve which gives you heat.
This is how the system works ,when you switch the control knob which is located inside the vehicle.There is the switch that gives you the hot or the cold.
Try this ,slide the lever that controls the defroster,you should hear a hissing sound which opens and closes the flap inside the dash.If it is not working this can also cause no heat.
Another possibility that can cause no heat is vacuum leak.The vacuum hose are loose or cracked OR the vacuum line is cracked.To confirm this get under hood and look for a broken vacuum line which is connected to a round ball .The ball is mostly black in color and has plastic lines connected to it.Now follow this lines and make sure that none of this lines are broken.If you notice any of the line is broken in between then go to auto parts store and find a rubber hose which will slide over the broken lines.Also be careful and when repairing They get really fragile.This lines are not very strong,so slide the hose bit slowly and carefully.
Check the vacuum tube to it if its not broken replace the valve. If the valve is leaking, coolant will be all over the transmission, its orange in color,on some car models.
In some cases trouble with the doors in the heater duct not opening properly. You might want to check the vacuum supply to the heater control switch in the dash.Check the vacuum tube to it if its not broken replace the valve. If the valve is leaking, coolant will be all over the transmission, its orange in color,on some car models.
If there is no vacuum leak,then check for coolant level,if its low then additional coolant needs to be added.
This basic testing details will help,you to confirm the problem for no heat on your car.