Ford Fiesta '01 - Heater Problem - Cold air when engine hot! - potuk

Morning,

Think this is more than likely the Heater Control Valve but wanted to check if anyone had any opinions as it seems strange fault to me.

My problem is that when the engine first starts until it reaches mid temp the air blown out of the heater is warm, but as soon as the car reaches temp the air out of the heater turns to cold air, all pipes front and back of the heater control valve are hot, and it cant be blocked as it is warm some of the time... any adivce???

Is the heater matrix likely to be blocked and is this a big job to replace?

Edited by potuk on 07/12/2011 at 06:46

Ford Fiesta '01 - Heater Problem - Cold air when engine hot! - TeeCee

So, in other words, the heater goes cold when the thermostat opens.

Air in the system sounds favourite. Try removing the filler cap when cold and then running it 'til warm with the heater on fully hot. Give it some medium revs to whizz the coolant round with the water pump. With a bit of luck you should get a good "burp" from the header tank as the airlock clears.

Ford Fiesta '01 - Heater Problem - Cold air when engine hot! - madf

Have you checked the radiator water level?

Does the car gurgle as it warms up?

Because you may have insufficient coolant...