Help! Have a System 2000 with 100 degree light flashing

MCarp

I went to a customer tonight who has a system 2000. When I got there burner was on reset. Replaced nfs and got it running. Then all of a sudden the heat manager started blinking at 100 and it was not reading the temperature as it was rising. When the boiler got to about 170. the burner paused for a second, the lights that indicate the temperature worked and it seem to be functioning. When the burner started to cycle the second time, when the boiler started to drop in temperature it went back to flashing 100. I am stuck on whether it is the temperature probe or the heat manger board? I turned down high limit to 180 because I believe it is running on limit instead of the board when it is flashing 100. Any input is appreciated.

furnacefigher15

This system 2000?

http://www.energykinetics.com/documents/digitalManagerHeatingProfessional/digitalManagerDiagnostics.pdf



Says loss of communication to the sensor.

billtwocase

flashing lights

As funacefighter said, it is a sensor issue. I would try resetting the manager first by simply turning the switches off, then back on after a few seconds. Also check the sensor wiring on the manager, tightness, connection. It may be a bad sensor, had a few of those, and keep them in stock. Turning the limit down is the thing to do, and you can also put it in service board mode by removing the red lead from the left side of the manager. Turn the switch back off to do this, then turn it back on. Just like using an actual service board, it will run like any other boiler. The circ will run constant, and it will run off the high limit, so set it to about 165. This will give you some time to order the sensor. 

MCarp

Thanks guys

Very much appreciated.