Hot and Cold air at the same time

I have a 1994 C280 and I will routinely get hot air from side dash air vents while getting cold air from center dash vents.

I had the codes pulled when some other repairs where being done and got #49 auxillary coolant pump bad.

Other codes are 28, 50, 62, 60, 80, 82, 100. The shop who pulled these codes acted like these where not important codes. Can you tell me what these codes mean?

I have been told to replace the auxillary water pump and that there is a switchover block temp flap intermittent failure. I was offered no solution to the switchover block temp flap problem.

I have found the auxillary water pump under the hood (and can easily replace that) and have read that its function is to maintain uniform heater core temperature.

Doesn't the switchover block work from a vaccum source.

How do I fix this?