Manifold to heater then return to the water pump is the correct direction. It sounds like you have an air-lock.
Ah, opposite to the way I thought and will explain why that hose gets hot first. Thank you.
I'd loosen the clip on the heater return hose and gently pull it away when the engine's just started to see if any air comes out.
I did this - got showered in fluid- there was definitely water coming out of the matrix. I'll have a crack again at the weekend and see if I can get any air out. Is there a preferred 'in and out' for the matrix? Currently the hose from manifold enters the matrix on the passenger left/passenger side and exits back to water pump on the right/drivers side.
If I was going to fit a tap, am I right to assume it should be in the hose going from manifold to matrix, rather than in the hose from matrix to pump (as fitted by Allon White).
