I have a coleman / evcon 2703-341 model BGUO7512A that will turn on, burners on, heat up and then shut down. Led flashes 4 times which is limit fault code. I assumed hi limit switch fault but upon further investigation found that the blower is staying on low speed which I figured would cause the heat exchanger to overheat and shut the furnace down. Once cooled down it fires up and repeats the process. I checked the A-coil and it is spotless. I removed the blower fan and it too is clean. Any suggestions on how to check if the motor is ok or if it's the board. Several years ago I had to change a relay on the board, that controled the motor, due to a burned out coil. is there another relay on the board that controls speed?
Also, I have been told that intermittently it did/does blow on a higher speed, but only occasionally
Last edited by AEROFANZ; 12-08-2010 at 02:29 PM.
Reason: clearer heading
After checking the board and the capacitor I determined that the motor was at fault. It would run on slow speed no matter which lead was powered up. Now to find a place to buy a replacement that won't try to rip me off or demand that I show them a gas licence for and electrical component....go figure.