yaris diesel,heater blows cold air..

[cccecider]

i have a yaris 1.4 diesel 2005..the heater keeps blowing cold air,even when the control is set to hot.changed the thermostat thinking it could be that but still no hot air...anyone got any ideas??

[kenora]

Not sure about the Yaris but many cars require you to vent air from the cooling system after opening it up. There might be a little nipple at a high point in the system to open. Then fill the system with coolant till it comes out that nipple (then all the air is gone). Also make sure the cabin heat is selected to max hot while filling.
fwiw!

[Shroomster]

automatic a/c or manual a/c knobs?

maybe blend door or heater control valve is sticking....