Suburban Mfg REGAL INTENSIVE CARE UNIT 12019-01-NGFREP - Manual (Page 165)

Form No. 702718 Rev. A March, 2005 153
Owner’s Manual - Regal Intensive Care Unit
Calibration knob will not move the calibration needle
This is almost always the symptom of an exhausted fuel cell in the
oxygen sensor. Replace the fuel cell. Order P/N 853396 and refer
to Page 85 for replacement instructions.
Remedial Action