My car's heater was working fine until it started blowing cold air (it's 34 or so outside). If I turn up the temp setting to 90, it blows faster but the air isn't any warmer. The engine temp is about half way up which I think is normal. The "outside temp" reading as displayed on the panel is correct. Is it still possible there could be a thermostat problem or is it likely something worse?

Other relevant facts:
1. My water pump has been leaking for quite some time. The coolant tank needs to be refilled about once per week which I've been doing. I will get this repaired, though.

2. I'm hearing a whining noise when I turn the wheel sometimes... this seems to be a steering column issue, but I'm not positive. I'll get this checked soon, but I doubt this is related to the heater.

 

Fix coolant leak and see if you have heat then.