If the above methods still can't identify the cause of the issue, we recommend carbonizing the probe. You can use a carbonizing device for this. When the oxygen probe is in operation on the furnace, the recommended air flow is 10-20 CFH, for a duration of 2 minutes, then observe the performance of the oxygen probe and atmosphere controller (if possible, turn off the recirculating fan during the carbonizing process). If the fault persists, it is necessary to thoroughly carbonize the furnace to completely remove contaminants inside (including the oxygen probe). Carbonizing the probe is harmless to the probe itself, as long as the temperature during the carbonizing process does not exceed 38°C (100°F). 10. If your atmosphere control issue remains unresolved, please contact SSi's technical support team.