Heater blows hot air only after the engine runs for 15 mins after starting on 2003 Toyota Corolla

Coolant level is normal.temp gauge is normal.once the car is heated up there is no intermittent proble

Asked by for the 2003 Toyota Corolla
3 answers
could be clogged heater core or a slow thermostat or partially open.

Can you feel the radiator core iteslf? Your thermostat could be stuck open or the heater core could have restricted flow. Call Jon at Dublin Auto (925)828-0243. He's a factory trained Toyota Tech and can check it for you.
Heater blows hot air only, when the car has warmed up?? Are you looking for cold air as in air conditioning? It can be mechanical or electronic, low on freon or blend doors not opening. call 925-947-2555 Andre or Bart