Heater only blows hot

[Scottie]

The heater/demister in my 97 GC constantly blows hot air. I get the message 'Temperature Sensor Fault' on the LED display screen.
The Temp gauge never moves from the centre position and the engine is not overheating.

Would replacing the thermostat cure this as it's a lot cheaper than a new sensor ? :idea:

 

[SteelHeadz]

The temp. sensor it's reffering to is the "in car temp sensor".