Just starting to figure out the water flow for my heating circuit. I expect to have at least one problem in the future and would like to know more about it.

I'm also starting to receive new hoses from Mercedes for the complete ( -1 ) coolant system.

I haven't started removing any components yet. But it looks like they might have intended to have that heater core supply two zones of heat. No other reason to have two pipes on one side that I can think of.

Also it appears the monovalve pump might push water down the hoses and metal pipe to the housing area for the thermostat and water pump. My initial thinking was that the water flow would be from the pump to the solenoid valve controlled by the climate control system.

Any knowledge about this?