Technical problem

[anth]

my heaters blow hot air then when i stop it blows cold but tonight its been blowing cold air all night any idieas. think it could be the themostate or head car has done 45300

 

[Punto.Power]

Ok, i wouldint drive it long untill i get that fix that can result in a HG failure, the 2 main common ones are air in the coolant system can cause it you need to get the radiator bleeded or as you said the thermostat is at fault they can be tested in hot boiling water sauace pan if it opens correctly and shuts correctly in cold water then thats fine, other suggestion would be waterpump but we wont get into that just yet try bleeding first if still accurs replace thermostat..