Error code of 6 flashing light on circuit board,

Check your board and see if it is flashing a code, Check your limit switches to see if one is open, Does your blower motor run all time? could be a board problem. You should have a wiring diagram on the inside of the electrical box

This sounds like the fan not turning during cool. You will have to check the fan relay for power during the cool cycle. The fan relay is run by the low voltage side, but still there is hi voltage present. When in heat the power goes thru the relay on one set of points then in cool goes thru the opposite side. You should have a digram present, and then on the main circuit board there is a code light. Check the light for blinking or (flash) read the bottom of the board for the code ( very small print)

How long does it run? a few seconds or a few minutes?
I would check the air filter first. Then next time it runs, check the circuit board for any flashing lights. You may have an error code stored. There should be a small viewing port in the lower panel that looks into the cabinet of the furnace. If you have to remove a panel to see the circuit board, you may shut off power to the unit which will erase any error code. Once you find the light, check on the wiring diagram that is pasted on the reverse side of one of the panels for a diagnostic chart. It may give you a starting point where to look if you have an error code.

Remove the lower panel and look for a wiring diagram pasted to it. On that diagram there will be an error code diagnostic chart. Depending upon which model you have it could be an open overheat switch caused by a dirty filter or a bad fuse.

You have to get in to the main circuit board. At the bottom of the circuit board it will tell you what the flashes mean, in very small print. Read this print for you codes.

The unit won't kick on if you have a float switch installed on the unit. The drip pan you are talking about, I think, is the emergency drain pain and you will find it sitting directly below the unit. It will be a big silver pan with pvc piping connected to it. If you turn the switch for the fan to on instead of auto, does the fan kick on? Do you have power to the unit? Have you manually reset the breaker to the unit? Are you getting an error code (flashing light) from the control board? Are there any lights on in the unit? If you can answer some of these questions, I can help you diagnose your unit correctly.

check your filter if thats clogged that will send a four flash limit open or your blower motor might be bad these units are known to have popped rings and cracks on thier heat exchangers if there isnt enough airflow if your filter is clogged or motor is shot i would call someone monday and get your heat exchanger inspected

The error code refers to a defective combustion air switch. Coleman Evcons made around 2007 had defective pressure switches or as they call them "combustion air switch". Replace it and the problem is gone.

does that unit run heating or just the fan run? if just the fan you may have a bad fan thermostat