Yeah as above !
Think I found a way to explain it..
The red hose in this picture will not be needed on the compact because there are only two ports from the bulk head.
When using the compact heater valve it only has two ports on the valve rather than the 3 that the 328 one has.
So use the 318 heater valve and connect the blue hose to where the red hose was connected to on the heater valve.
Hope that makes some sort of sense!
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