Diagnostic LED’s: SFS
SFS “on”
A)Is the Stack Flue Switch or Sensor correctly connected to the wiring harness?
B)Is the Membrane Pad connected to the correct pins on the Control Board?
(See Page 36)
YES
Check the J3 and J6 NO connectors for corrosion
on the male pins. Corrosion found?
YES
Clean pins
DONE
Reset power to Heater and retry. Heater should fire.
NO
Verify whether you have a Stack Flue Sensor or a Stack Flue Switch
(See Page
NO
NO
Reconnect correctly.
DONE
Reset power to Heater and retry. Heater should fire.
Replace Stack Flue Sensor.
YES
Does the Digital Temerature Display show Error Code “E05” or “E06”?
SENSOR
NO
Replace Heater Membrane Pad Assembly, reset power to Heater and retry. Heater should fire.
NO
Replace Heater Control Board with new style board, reset power to Heater and retry. Heater should fire.
NO
Change Low Level Board Programming to “SF1” (See Page
YES
Reset power to Heater and retry. Heater should fire.
NO
Check Heat Exchange Coil for liming or low flow.
SWITCH
Does the Digital Temerature Display show Error Code “E05” or “E06”?
NO
Reset power to Heater and retry. Heater should fire.
NO
Replace switch, reset power to Heater and retry.
YES
YES
Change Low Level Board Programming to “SF0” (See Page
Check Heat Exchanger Coil for liming or low flow.
YES
NO
Reset power to Heater and retry. Heater should fire.
YES
Did Error Code (E05 or E06) disappear after change?
NO
Replace Heater Control Board, reset power to Heater and retry. Heater should fire.
NO
Replace Heater Membrane Pad Assembly, reset power to Heater and retry. Heater should fire.
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