Got a strange situation;

Car is wanting to overheat-BUT at the same time the heat isn't working.

It has been minor before now-usually in town driving with the Air running. So I flushed it out and replaced the coolant.

Still doing it. Then tonight all of a sudden it maxed out and I tried running the heat to bring the temp down but no heat was coming out of it.

Now the second fan on the radiator, usually the air conditioner fan, hasn't been working but that doesn't seem to me that it would cause the whole problem. I would understand if it was just from idling too long with air on.

Any Ideas? could the thermostat be stuck closed so that it is overheating and with no water the heat doesn't work?

Any ideas would be great. Thanks!