So recently purchased this car, so far loving it. The heater is not working properly, it only emits cold air. If i do have it on ‘heat’, and turn the fan on, it makes a clicking sound. I was told it was some sort of heater valve that is not engaging, wondering is this sounds right and if so, what exactly is the part called and how much does that run…? I’m not very well versed in
auto mechanics, wish I was. If anyone can help, I would be very grateful and so would my kid sitting in a cold car… 
It’s the blend door. The heater core has no valve to it. Temperature is regulated by a blend door that splits the air, some through the core, some by-passing it. The stepper motor that controls this blend door is malfunctioning. It should be accessible under the glove box portion of the dash, but may involve more disassembly of the dash than that.
Thank you very much for your help. It’s very appreciated! Happy New Year to you and yours…
It may not be the motor assembly. It may be the plastic blend door itself. These are known to break where they go into the motor assembly. It’s a lot more work to replace the door, so lets hope it’s the motor.