If you are talking about the thermostat in your engine, the two have nothing to do with eachother. If there is no air at all coming out the vents, I suggest it is your blower motor.
Check into the temperature control valve--this is different than the thermostat.
How did you change the thermostat?
it could be that you've put too much coolant to percentage of water in
I suggest replacing the thermostat, that might work.
The thermostat is stuck open and needs to be replaced.
Check coolant level check blower motor fuse Check the thermostat
The heater valve could be failing to open for one reason or another.
No. The thermostat is not likely to be the cause.
Could be a head gasket or a warped or cracked Cylinder head.
The temperature blend door may be at fault.
If your engine is overheating and has no obvious leaks then suspect the thermostat. Of course you can remove it and check it, but the best thing to do is just replace it if it is suspect. It should be replaced every time you service the cooling system. when you turn your heater on the it wont blow hot air
Sounds to me that the thermostat is in backwards.