Universal Silicon Carbide Integrated Ignition Control

White Roger recommends this unit to replace it's older 50A50 line of controller board and it works as advertised. You may have to jumper the OD1 and OD2 pins on the 12-pin connector if your furnace don't support this feature. Look to see if there are wires on the OD1 and OD2 pin of your existing 12-pin connector. The pin layout is on the controller board. Use the black jumper wire that come with the replacement unit to jumper these two pins on your existing 12-pin connector if your furnace doesn't support this safety feature. What I really like about this replacement unit is the on-board diagnostic function indicated by the flashing LED and the product manual that came with the package. After I installed the unit and power on, the diagnostic LED flashes 5 times so I looked up in the manual to find the OD1 & OD2 issue. Since my old furnace doesn't have this feature, I jumper the two pins and power the unit on again. This time the diagnostic LED flashes 4 time indicating the (temperature) limit switch is open. I look up on the internet to find out what the limit switch looks like, locate the switch and ohm it out (with the power OFF). Apparently my limit switch is stuck open and need to be replaced. A temporary fix is to unstick the switch by flicking my finger against it several times. This will work until it stuck open again so REPLACE this part. When I put everything back together, the furnace came on and the family have heat once again. Apparently my old controller board still work b'cuz my problem was the limit switch stuck open. However, the diagnostic function on the old controller board did not help me to figure out the problem so I opted to leave the new one in my furnace. This newer unit will help me to diagnostic any problems that may occurred in the future.

I purchased the 50A55-843 as a replacement for the 50A50-405 on a Cumberland Model FCAC100A50A1 that was used for the second stage heat in a dual-fuel heat pump system. When installed in furnace the blower would run all the time and the burners would not come on when the system was calling for emergancy heat. This was the case regardless of where the thermostat was set. Found a new 50A50-405 locally, installed it and everything went back to working.