santa fe is dripping water when running hearter

No it is not. You have a leak somewhere that needs to be found. Look to see what area the drip is, look at heater hoses, all coolant hoses. Depending on where the leak is it may be a water pump.

If you are smelling anti-freeze inside the car, that is a good indication of the heater core leaking. Still look at the heater hoses running up to the heater core.

If it is clean water that is dripping at the firewall on the passenger side there is a chance it is condensation from the AC unit. The AC may come on to de-humidify the air inside your car.

This is exactly what my car is doing when i turn the heater on!