1998 BMW 328 Has Never quite worked

Heater problem
1998 BMW 328 6 cyl Two Wheel Drive Automatic 240K miles

Hi there,

I have recently been driving my father's car and noticed that the heater does not work properly. More specifically it is not shooting out hot air even when fully blasted. I think that a similar issue exist during the summer months with respect to the air conditioning.

I really want to resolve both of these issue and wanted to get an idea of how much anyone thinks that it would cost to fix these two issues.

Thanks,

GT