The bottom pipe of my heater matrix is hot but the top one is cold. I have flushed the matrix through with a hose and when the hoses are disconnected from the block I do have a continual flow through the matrix.
Could this problem have anything to do with the thermostat?
I have tryed everything else.
I know it is not an air lock as this system has a bleed valve at the highest point.

Alan Morgan, December 2006

is the valve opening which controls the water flow thru the matrix,if ur not sure move the switch from hot to cold inside the car to locate it then strip to check.its a common fault on this model

phlipflop, December 2006