I think it's called a heater core, but I can't find it on majestic honda. It's a plastic piece that is connected to the engine, on the tranny side by a coolant hose and the other side of the plastic peice goes into the fire wall. It has a wire on the top of it that adjusts the heater temperature. I was replacing a hose for a friend and it broke on me. whoops. For now I just used a connector and let it blow super hot air all the time.

 

That is the water valve assembly. Honda part number 79710-SV4-003

If you go back to majestic you should be able to find it under the heading Electrical/Exhaust/Heater/Fuel - Water Valve

 

Thanks