Error 2920 V

Safety precautions:

- If you smell gas: stop using appliances, do not operate electrical switches, open windows and doors, turn off the gas at the meter or emergency cock if you can do so safely, evacuate the property and call the National Gas Emergency Service immediately. Do not attempt any checks beyond evacuating and calling the emergency number.

- Before any physical inspection of the boiler, switch the boiler off and isolate power at the mains. If you are not competent with electrical or gas work, do not open the boiler casing or touch internal parts. Only qualified engineers should carry out internal fault-finding and repairs.

- Do not repeatedly press reset more than once or twice. Repeated resets mask underlying faults and can be unsafe.

Initial checks a homeowner can safely do:

1. Note the exact fault code (2920 V) and any other display messages or flashing lights, and when the fault occurs (during ignition, after a few minutes running, after a power cut, etc.). This information is useful to the engineer.

2. Try a single reset: switch boiler off at the programmer, wait 30 seconds, switch back on and press the boiler reset button once. Wait to see if the boiler attempts to light and whether the fault returns. If it reappears immediately or after one attempt, stop resetting.

3. Check the household gas supply: confirm other gas appliances (hob, gas fire) work. Check that the gas meter/gas isolation cock is on. If other gas appliances have no gas, contact your gas supplier — do not attempt internal boiler work.

4. Check mains power and fuses: ensure the boiler has power and any switched spur or fuse is on. A power interruption can sometimes cause control faults.

5. Check boiler environment: make sure the boiler and flue terminals are not blocked and the boiler hasn’t had water ingress (wet PCB) or condensation sitting on components. Do not attempt to dry electrical components yourself beyond ensuring the area is dry and ventilated.

6. Check system pressure: although not a primary cause for flame monitoring, ensure central heating pressure is within the normal range (check your manual). Low pressure is not likely to cause 2920 but is worth confirming.

Specific diagnostic and repair steps (for a qualified Gas Safe engineer):

1. Retrieve service logs and run any available service mode or diagnostic menu to record flame signal strength and ignition sequence timing. Note whether the fault is “no flame signal after ignition” or an intermittent/false signal.

2. Inspect electrodes and leads: check the ionisation/flame sensing electrode position and condition, correct the gap and alignment if required, clean or replace the electrode and replace the ionisation lead if corroded or damaged.

3. Check ignition electrodes and ignition leads: verify the ignition spark and lead continuity. Replace faulty ignition components if present.

4. Measure flame signal (mV) during ignition and running. Compare against manufacturer values. If the flame signal is absent or too low the engineer will proceed to isolate whether the sensor, cable, or return path (earth) is at fault.

5. Inspect wiring and connectors between electrode, gas valve and burner control unit (PCB). Repair any loose or corroded connectors.

6. Check modulating gas valve feedback circuit (related codes 2924/2925): verify the gas valve control/feedback and replace the gas valve if feedback is absent or out of range.

7. Test the burner control unit (BCU)/PCB: if flame signal circuits and gas valve are correct but error persists, the control unit may be faulty and require replacement.

8. Perform a full ignition and safety check after repairs, verify there are no false flame signals (flame detected when off) and run CO/combustion checks as required to ensure safe combustion.

When to call a professional:

- If the fault reappears after one reset, if you cannot identify a simple supply issue (power or gas), or if anything requires opening the boiler casing, call a Gas Safe registered engineer. Flame monitoring faults involve gas and ignition components and must be diagnosed and repaired by a qualified engineer.

- Provide the engineer with the exact fault code (2920 V), details of when it occurs, and anything you observed during your checks. This speeds up diagnosis.

Additional notes:

- Do not attempt to replace gas valves, PCBs, electrodes or perform live electrical checks yourself unless you are Gas Safe and competent. These are gas/electrical safety-critical operations.

- If you suspect water ingress, damp or corrosion on the PCB or wiring, mention this to the engineer as it often causes intermittent flame monitoring faults.

- Keep a record of fault occurrences, resets and any other codes shown — useful for the attending engineer.