Originally Posted by pizzachef

I just installed a lower radiator hose heater I bought from NAPA (looks similar to the one offered by diesel giant). After I wrestled the hose onto the both sides of the heater and reinstalled the hose, I looked at how the water flows. This heater will heat the water in the radiator and up to the t-stat. But the t-stat will be closed, so how can it warm the engine block? It must somehow right? Its driving me bonkers and I was so excited to have a warm engine engine for the rest of thie winter...

Can anyone explain it to me?