DemirDöküm Boiler Error Codes: F-Codes Meaning and Fixes
On DemirDöküm boilers, F1 signals flame formation/absence, F2 overheat protection, F3-F5 flue/NTC faults, while N codes indicate gas/water supply states. The common F1 appears when the gas valve is closed, gas is out, or the igniter is dirty; switching off, checking the gas valve and resetting fixes most cases. F2 overheat triggers with closed radiator valves or pump faults — check pressure and valves before resetting.