for 启动 problem, watch the thermalstat and see it works or not. when actual temperature is higher than the set temperature, the switch in thermalstat is activated, and you can hear a "click". Then the conditioner should start. otherwise, something may be wrong with thermalstat. To have higher confidence on this, you can measure the voltage on control module (on furnace, close to air circulating motor) and see there is 24V output from thermalstat or not. But this needs some knowledge and experience.
