1995 BMW 740 Heater core issues

Heater problem
1995 BMW 740 V8 Automatic 120000 miles

Ok, so my car is having issues with pumping anti-freeze into the heater and then going into the cabin.

We currently cannot afford to have it replaced, and so we're trying to make a temporary fix by re-routing the hoses just before the heater core, after the water accumulation(What does this do, anyway?), And avoiding the heater core all together until we can get a better fix. Obviously this will leave me without a heater until further fixes. If you have any information for me, like why there are 3 tubes going into the water accumulator compared to the normal 2 in every other car, that would be greatly appreciated.

Thanks,
Leth.