Why don't my heater get hot

you need the cables to hold the door in position and there should be a vac hose coming out of the fire wall somewhere, that has to be hooked up...both of these things have to be hooked up to have the heater working.

you don't need the inline valve in the heater hose, thats for a/c...to keep the flow of hot water out of the core when a/c is on.