Boiler Troubleshooting
Quick reference guide for the Arcelik DGK 20 DI combi boiler installed in Lojman apartments.
Error Codes
When your boiler displays an error code, find it below for a quick diagnosis.
Ignition Failure
The boiler attempted to ignite but failed after multiple tries. Possible causes: gas supply interrupted, ignition electrode dirty or damaged, gas valve fault.
Check that your gas supply is on (verify other gas appliances work). Check that the gas shutoff valve below the boiler is open (parallel to the pipe = open). Try resetting the boiler by turning it off and on.
If gas supply is confirmed OK and the error persists after reset, email mainhelp. The ignition electrode or gas valve likely needs servicing.
Safety Thermostat Triggered (Overheating)
The boiler's internal temperature exceeded safe limits and the safety thermostat cut off the flame.
Wait 10 minutes for the boiler to cool down, then reset. Check that all radiator valves are open (at least 2–3 radiators must be open for proper circulation).
If error recurs, the circulation pump or heat exchanger may be blocked. Email mainhelp.
Flue Thermostat Fault
Exhaust gas temperature exceeded safe limits, or the flue thermostat sensor is faulty.
Do not attempt to fix. Email mainhelp — the exhaust system or sensor needs professional inspection.
Repeated Flame Loss
The boiler ignites successfully but keeps losing the flame. Often caused by wind/draft affecting the flue, or intermittent gas supply.
Reset the boiler. On very windy days, this can be a temporary issue. If it resolves after one reset, no further action needed.
If error occurs repeatedly even in calm weather, email mainhelp. The flame sensor or flue terminal may need attention.
Heating NTC Sensor Fault
The temperature sensor on the heating circuit is reading out of range (open circuit or short circuit).
This is a sensor or wiring issue. Email mainhelp.
DHW (Hot Water) NTC Sensor Fault
The temperature sensor on the domestic hot water circuit is faulty. Hot water temperature cannot be properly regulated.
Sensor replacement required. Email mainhelp.
Low Water Pressure
System pressure has dropped below the minimum threshold (below 0.5 bar). The boiler cannot operate safely without adequate water pressure.
Look at the pressure gauge on the front of the boiler. Normal operating pressure should be between 1.0 and 1.5 bar. Open the filling valve (small tap underneath the boiler) slowly until the gauge reads ~1.2 bar, then close it. The boiler should reset automatically.
If you need to top up pressure frequently (more than once a month), there may be a leak in the system. Email mainhelp.
Circulation / Pressure Fault
Air trapped in the system or a pressure irregularity is preventing proper water circulation. This is the most common error reported by residents.
There is a valve underneath the boiler (usually red). Turn it to the left — this releases excess pressure and resets the boiler. Once water/air stops coming out and pressure normalizes (check the gauge reads ~1.2 bar), close the valve.
If the E25 error keeps coming back frequently, email mainhelp. There may be a persistent air ingress or pump issue that needs professional attention.
Parasitic Flame Detected
The boiler detects a flame signal when no ignition has been commanded. Usually an ionization electrode or PCB (control board) fault.
Do not attempt to fix. Turn off the boiler and email mainhelp immediately.
Low Voltage
The electrical supply voltage to the boiler is below acceptable limits.
Check if there is a general power issue in your apartment. Try unplugging the boiler for 30 seconds and plugging it back in. If there's a voltage stabilizer, check it's working.
If error persists, the electrical installation may need checking. Email mainhelp.
Gas Valve Fault
Internal gas valve is not operating correctly. The boiler's control board cannot properly command the gas valve.
Do not attempt to fix. Turn off the boiler and email mainhelp. The gas valve or control board needs professional inspection.
Internal Communication Error
The boiler's internal components cannot communicate with the main control board.
Turn the boiler off, wait 60 seconds, and turn it back on. This can resolve temporary glitches.
If error persists after reset, the control board may need replacement. Email mainhelp.
General Tips
How to Reset
Turn the boiler off using the power switch (or unplug it), wait 30–60 seconds, then turn it back on. Most transient errors clear after a reset.
Ideal Pressure
Keep the system pressure between 1.0 and 1.5 bar (check the gauge on the front). Below 0.5 bar or above 2.5 bar will trigger errors.
Winter Prep
Before the heating season, bleed all radiators to remove trapped air. Start from the lowest floor and work up. This prevents E25 errors.
When to Call Help
If you smell gas, hear unusual noises, or see water leaking from the boiler, turn it off immediately and contact security/mainhelp.