If I turn off the power and then on again, it works fine for a couple of days, then the same thing happens. The furnace techs have replaced the flame sensor, the blower, the reset button on the top and its getting expensive. The furnace was cleaned 3 months ago. It blinks 12 and 14 sometimes. When reset, it comes on steady and works. Getting tired of having to wake up just to turn it off and on. Have lost faith in Tech.

If you don't have a good ground (equipment ground)on the gas valve and burners you can get the same symptom.

Thank you for your answer. I checked all the grounds, everything tight. I still have the same problem. It may run correctly for a day, two days or one hour, but then it doesn't come on without turning off the 110v and turning it back on again. The LED blinks code 14 until the power is turned off, then it comes on steady when the power is turned on again.