Have a Evcon Coleman Furnace shows three green blinking lights but will not ignight what could be wrong

Steady light on - normal operation.
One flash - ignition failure.
Two flashes - combustion air switch stuck closed.
Three flashes - combustion air switch failed to close.
Four flashes - limit switch open.
Five flashes - gas valve energized with no call for heat.
Rapid flashing - reversed polarity.

Note: Color of light is green.

There should be a diagnostic chart on the furnace door by the wiring schematic. If so see what the code reads for three blinks.
By the term "air combustion switch" I guess you are referring to the pressure switch. Most diagnostics blinking three times is just a dirty flame sensor. If this is the case the burners will light and go out within 4 seconds. If this is the problem carefully remove the flame sensor and clean gently with emery cloth, fine sandpaper or fine steel wool. Reinsert the sensor and enjoy your heat.

Usually on a metal panel you have to remove to access the board there is an electrical diagram. On the side of that is usually a description of what specific blinking codes mean.

www.repairclinic.com/Shop-For-Parts/a36b383/Coleman-Furnace-Parts

Coleman Evcon Furnace Error Codes


this will help you

try jumping out the presureswitch this may fool the heater in too working ,

change the pressue switch ,

Hi, I would just make sure you have power to the furnace. Check breakers or look for the power switch on the electrical box. Also, some mobile homes have a wall switch that cuts power to the furnace.

colman uses the furnace to power the attic vent fan . Cheaper that way I guess. It just supplies your attic fan with power so it will vent thus keeping your home a little cooler in the summer.
not a big deal. you can shut the alarm with a switch ot cut power to the alarm.

Defective combustion air switch. The 3 blinks are an error code. You didn't say, but I'm guessing you have a Coleman Evcon. They had alot of defective Combustion air switches. Your specialists were not that.