mastercool plus thermostat

[fhorta]

hi. t stat on mastercool is not working properly. one day the fan just it came.on by itself. now the only way to turn it off is by turning off at the main circuit breaker box. Also the only way I can turn it off. water pump and speed can still be.controlled by t stat. t stat is tekelek brand and from what I know is the manufacture t stat that came with it. previous owner said this happened before and ordered this t stAt and like I.said had been fine until now.

my question is , is there a wire that can be disconnected on the air handler unit so.that cooler can be turned on and off from t stat again? also, if t sstAt needs replacing, can any tstat do or does it need to be tekelek again? thanks.soo much!