Hi,
I have a Concord 80 plus furnace that lights and burns normally. The burners will kick on several times. After the cycle it shuts off and flashes error code six, system lockout. If I shut the power off it will repeat the cycle and shut down again. When I turn the power on the blower kicks on and after a few minutes the burners light for several cycles I have cleaned the flame sensor with no luck.

Any assistance would be greatly appreciated.

Thanks

Did you have any luck with your furnace? We're having the same issue. Seven year old furnace, new thermostat. Furnace turns on, blows hot air, but won't maintain the temperature on the thermostat. If switched off and on again, it works for awhile, but still won't keep up.

Any input would be helpful... thanks.