What do I do about a blinking thermostat code "L6"? Make is Bryant Is there anything I can do, or do I need a furnace repair service?

Is the furnace working? Not having info ,or model number of tstat it is only a guessing game, could be that its telling you filter needs cleaned or replaced. Some tstats have the code written on inside of the cover,, kill the power /at the breaker ,1 minute later back on, is the prob. Still there?,