Boiler & Appliances IT

DemirDöküm Boiler Error Codes: F-Codes Meaning and Fixes

~8 min 5 steps Verified:

Short answer

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.

Official page

demirdokum.com.tr/destek

Open link

Official DemirDöküm support page

01 — Step by Step

Step-by-step fix

  1. Write down the code on the display

    Note the letter-number code on the boiler panel (e.g. F1, N2). Repeated codes mean a persistent fault; a single appearance may be a transient interruption. Record the model (Nomax, dtw, Soyut etc.) too — the official support page has model-based tables.

  2. F1 — flame loss: check gas supply

    Ensure the gas valve is open (the gas tap next to the boiler should be aligned with the pipe). After a gas outage, test other gas appliances. On LPG/regulator systems, check the regulator. Open valves and reset the boiler (hold reset 3-5 seconds).

  3. F2 — overheat: check valves and pressure

    Verify all radiator valves are open; closed valves block circulation and overheat the boiler. Pressure should read 1-2 bar; if low, fill to 1.5 bar via the filling loop. Reset after these checks.

  4. F3/F4/F5 — flue and NTC faults

    These codes indicate flue blockage, flue NTC or water NTC faults. Visually inspect the flue terminal outside for nests, ice or soot. NTC failures are not user-serviceable parts — service is required.

  5. N codes — supply/shortage states

    On most models N codes are not standby but status notices: 'no gas / low water pressure / preparing'. If pressure is low, fill it; if the gas valve is closed, open it. If the code persists after 10 minutes, open a service ticket.

02 — FAQ

Frequently asked questions

01How many times can I reset a DemirDöküm boiler before calling service?
If the same code returns 2-3 times in a day, stop resetting; repeated resets stress the pump and gas valve. After two reset cycles, opening an authorized service ticket is the right step.
02How long does F1 take to clear after a gas outage?
If the gas is back and valves are open, ignition returns within 1-2 reset attempts. If not after 5 attempts, the igniter electrode or gas valve needs checking — user intervention ends here.
03The display shows odd text like 'YEREL/İKİ' — is that an error?
On some models the panel language/label setting may have changed; the manual has the code table. Odd wording is often a panel setting, not a fault — long-press the menu key to switch the language back.