IaM-Ray posted:Those are usually installed at the high point. Is there a high point in our system? Maybe near the engine but the flow of the coolant at that area might affect it. What say you kind Sir, Stan ?
These would be completely unaffected by flow, as a hyronic heating system has at least as much flow as your engine.
A vent is always in the high point of a system, or at a localized high-point where air can be trapped. It's a good idea to put a vent at every one of these points in a hydronic heating system, and I'd assume if the cooling system on a Subaru is convoluted with any traps, vents in those places would be a good idea. If the heads are where coolant is trapped, I wonder about drilling and tapping the heads for coin vents. 1/8" NPT is pretty stinking little.