What to do if my FULTON FHE-250 Boiler shows lock-out error codes?
- NNicholas LongJul 29, 2025
If your FULTON Boiler shows lock-out error codes, it could be due to several reasons. First, check if manually operated valves on the gas train have been closed and open them, including the T-handle valve in the boiler shell. Second, inspect the gas line for any blockages, considering other equipment connected upstream. Third, ensure the tube between the gas valve and the Venturi is properly connected at both ends. Finally, the modulating gas valve might have failed, requiring replacement.






