Hot Air Problems

[gazeebo]

Hi all.Quick question concering my wife's 1999 T'reg Fiesta 1.25 16v Zetec.I've done a bit of searching on here and found a few similar queries so I apologise beforehand if I ask something previously answered.It's to do with the car heater not being able to blow hot air.I've done all the head gasket checks and they all came back negative(no overheating/oily water/watery oil etc.Something troubling me is to do with the hoses which go into and out of the heater matrix.I take it one of them is the outlet and the other is the inlet.If you stand in front of the car the hose on the left has an arrow pointing towards the engine which I assume is the outlet.What I'm not too sure about is why the hose on the right, going into the bulkhead/matrix is cold and the other three hoses are hot....is there a blockage in the heater matrix or would it be more likely be a knackered Heater Control Valve.Oh! and before I forget does anyone know the code for the Idle Control Valve because I'm getting conflicting answers...is it XS4U-9F715-DA or XS4U-9F715-BB.Many thanks for any info,muchly appreciated.Gazeebo.