[BOBOCobra]

I use the heat circuit as the bypass, heat valve is normally open and always circulates. Rather than going though WP bypass I route it out of the manifold through the heater core back to the rad and that's how I circulate prior to T-stat open. It gives me a little more flow and allows a nice even warm-up. Hoses on both sides of heater core are hot so I know its flowing. I also have 3-1/8" holes in t-stat for circ so no pressure can build should there be a problem and allows air to escape. There is plenty of bypass going on, no way this should create a hot spot, yet....that fitting area is exactly where it is hot, all the time, even if t-stat is open and full flow.