HI,

My carrier furnace model 48DJE006510 suddenly run all the time and the temperature show as 81F in the thermostat even I set at 68. I move the swith on the thermostat to OFF position but cannot shut off and the temperature continuing go up. I try to debug the problem by open the thermostat and disconnect one wire at the time until all the wires (Y, R, W, G, B) were disconnected but the furnace cannot shut off. I can only shut off the furnace by shut off the power switch in the main power pannel.

Thanks,
Tan

Then shut off the power switch and call a repairman. There are several things that could have happened, and it will require troubleshooting. No offense, but the way you stated the question and what you did at the thermostat (not bad, but not knowledgeable), leads me to think you are not experienced in furnace repair.

EPM