Fan was constantly running when set to auto. No codes were showing when I arrived. Cycled the power off to furnace & turned it back on & ran it on test mode set to heat. Test mode worked just fine. Ran the heating out of test mode 3 different times & it cycled on & off the heating & blower when it would meet temperature on thermostat like normal. Whatever was causing it has stopped. Mentioned if it happened again we could get on the phone with an FSR & go more in depth to prevent it from happening again. No issues to report.