i turned off the power at the RTU changed the blower belt then restored power, when i checked the thermostat it appeared to be locked out i tried to unlock it by pressing the 2 blue buttons Mode & Fan but was unsuccesful i am unable to program it at this time, also i do not have any kind of manual on this thermostat if you could supply me with a copy of one online it would be very hwlpful. Thank You. Tim Lund.