how do i fix the heater on my renault megane?

is it low on water first,then is the radiator warm and temp gauge in warm /normal place.then you will need to check the flaps to see if there working to let the hot air into car.if its not hot in may be the termostat not working but the most common is water low and heater goes low first so no hot water to warm air

bob
March 2012