Most cars were built without an AUX waterpump, why bmw decided to put one in is beyond me.
Heater valve not working. Heater valve can be stuck in the open position or closed position. Open being it will not close thus getting a continues flow of hot coolant/water into the heater core giving you heat at all times. Or it can be stuck closed not letting any hot coolant/water into the heater core thus giving you no heat in the Cabin.
Usually if you knock it a couple of times with your hand or a blunt object it'll start to work.
You'll be o.k with that bypassed for now.
95 530i|Modifications - Work.