My heater not working in toyota estima just blowing cold air.what can i do to fix it

As per your problem mentioned.There are few solved help links to troubleshoot these problems.Go through the list and Click the link below:----
Air conditioner blows air but not cold air http://repairhelpcenter.blogspot.in/2012/07/air-conditioner-blows-air-but-not-cold.html

------------
Car overheats and Air blows hot at idle? http://howtobyme.blogspot.com/2011/11/car-overheats-and-air-blows-hot-at-idle.html

------------
Heater blows cold? http://schematicsdiagram.blogspot.in/2012/02/heater-blows-cold.html

-----------
Heat blows cold on drivers side and hot on passenger side? http://schematicsdiagram.blogspot.com/2011/12/heat-blows-cold-on-drivers-side-and-hot.html---------- Hot air on the driver's side vents only? http://repairhelpcenter.blogspot.com/2012/01/hot-air-on-drivers-side-vents-only.html

--------------
2005 Chrysler PT Cruiser: A/C Blows Warm? http://whoisbyme.blogspot.in/2012/06/2005-chrysler-pt-cruiser-ac-blows-warm.html

-----------
1992 Toyota Camry: A/C Control light Flashing and A/C not Blowing Cold? http://technoanswers.blogspot.in/2012/04/1992-toyota-camry-ac-control-light.html

--------------
No heat, blower blows only cold? http://technoanswers.blogspot.in/2012/02/no-heatblower-blows-only-cold.html

------------
These will help.
Thanks.

Check out related help links with solutions to troubleshoot the problem:---
Click the link below:---
2004 Toyota Tundra: Oil Gauge and Temp Gauge Not Working?

http://howtobyme.blogspot.in/2012/05/2004-toyota-tundra-oil-gauge-and-temp.html

---------
Toyota 4Runner: Temperature Gauge Sensor http://technoanswers.blogspot.in/2012/04/toyota-4runner-temperature-gauge-sensor.html

-----------
Temperature gauge sits over half way mark? http://schematicsdiagram.blogspot.in/2012/04/temperature-gauge-sits-over-half-way.html
----------
Heater blows intermittently and temp gauge goes erratic?

http://technoanswers.blogspot.com/2012/01/heater-blows-intermittently-and-temp.html
------------- No heat on Oldsmobile Silhouette? http://technoanswers.blogspot.in/2012/02/no-heat-on-oldsmobile-silhouette.html
-------------
Temperature gauge does not move and no heat when heater is ON? http://technoanswers.blogspot.com/2012/01/temperature-gauge-does-not-move-and-no.html
----------
Temperature gauge keeps fluctuating up and down close to red? http://technoanswers.blogspot.com/2012/01/temperature-gauge-keeps-fluctuating-up.html
----------- Temperature gauge on the dash quit working on Pontiac Grand Prix? http://technoanswers.blogspot.com/2012/01/temperature-gauge-on-dash-quit-working.html
-----------
Dodge neon gauges not working? http://technoanswers.blogspot.in/2012/02/dodge-neon-gauges-not-working.html

---------
Heater blows cold? http://schematicsdiagram.blogspot.in/2012/02/heater-blows-cold.html

----------
Heat blows cold on drivers side and hot on passenger side? http://schematicsdiagram.blogspot.com/2011/12/heat-blows-cold-on-drivers-side-and-hot.html

-----------
1992 Lexus LS400: Engine overheats, Antifreeze out of reservoir and heater Blows Cold Air? http://whatisbyme.blogspot.in/2012/05/1992-lexus-ls400-engine-overheats.html

-----------
These details will help.
Thanks.

could be your heater core, um try checking the heater assembly in the dash, something may have broke so the heat isn't being switched over, and it is staying on cold. Regularly check the fluids in the motor and top up as needed

Sounds like your heater core went out or is plugged, try doing a coolent flush on your system and if that dont work then youll propably have to replace the heater core. Hope this helps

have your themostat replaced it is very inexpensive

The air conditioning system need to be fill with gas,there is not enough gas in it that why it is doing that,Hope that help you,If there is not enough gas ,when you switch on the ac button it turns the ac compressor and cut off immediately because there is not enough gas.

If the engine temprature does not reach the normal level as it used to, it may be the coolant thermostat.

Iif it does, it could be air diverter gates not working properly, cold air blowing at a a light could point to that. The diverter gates are located under the dash.

It also coul be the valuve that controls the water to the heater core, but unlikely cause of the cold air at a light.

you must the coolint.

nothing try back flushing heater core, they clog up due to litle water preasure,you might want to flush cooling system if you already havent, hope this hleps.

Check the valve that controls coolant flow to the cabin