Error E92

Safety first

1) If you or anyone suspects a gas smell or a carbon monoxide alarm triggers: evacuate the property immediately, call the national gas emergency number and do not re-enter until the scene is declared safe. Do not attempt to relight the boiler.

2) Do not open the boiler casing or attempt any internal repairs unless you are a qualified, Gas Safe registered engineer. Isolate electricity only if instructed and confident to do so.

3) Turn the boiler off and leave it off if you are unsure; repeated attempts to force it to run can make a hazardous situation worse.

Initial homeowner checks (safe, non-intrusive)

1) Note the exact code, any accompanying LED indications and what the boiler was doing when the fault occurred (e.g. initial commissioning, after a power cut, during heating demand). Take a photo of the display if possible.

2) Try a simple reset: follow your boiler’s reset procedure (typically press and hold the reset button for 3–5 seconds). If the code returns immediately or after a single restart, do not keep resetting repeatedly.

3) Check other gas appliances in the house to see if they are working (hob, oven). If all gas appliances are out, there may be a gas supply issue—contact the gas supplier; do not attempt internal gas checks.

4) Visually inspect the external flue terminal for obvious blockages (bird nests, leaves, debris) from ground level only. Do not climb on roofs or attempt to dismantle the flue.

5) Check the boiler pressure gauge. If the system pressure is significantly low (well below 1.0–1.2 bar), top up to the normal operating range per your manual and retry. Low pressure can affect combustion and ignition sequences.

6) Ensure the boiler has a stable electrical supply (no tripped fuses or RCDs) and no recent brownouts occurred. Low voltage can disturb combustion controls.

If initial checks do not clear the fault or the fault is intermittent

1) Record when the fault happens (time, cold/hot start, after power interruption). This information helps the engineer diagnose intermittent gas/voltage/flue issues.

2) Do not attempt to adjust gas pressure, air shutters, fan wiring, or ignition components yourself.

When to call a professional and what they will do

1) Call a Gas Safe registered engineer if the reset does not clear E92, if the code returns repeatedly, if you found a blocked flue you cannot clear safely, or if you suspect gas supply instability. Provide the engineer with the boiler model, serial number and the E92 code plus any additional codes or symptoms.

2) The engineer will perform safe, qualified diagnostics: verify gas supply pressure, inspect and test the fan and fan wiring, check flue thermistor and flue pathway for restriction, inspect ignition and flame detection electrodes, check mains voltage and frequency, and test the PCB for faults.

3) They may run a flue gas analysis and re-run the boiler’s auto-calibration/combustion setting. Depending on the findings the fix could be clearing a flue obstruction, replacing a fan, thermistor, ignition electrode, gas valve or PCB, or correcting a supply issue. All component-level work and any combustion tuning must be completed by a qualified engineer.

Final notes

1) Do not ignore E92: it is a combustion-related safety lockout and the boiler is protecting against unsafe operation. Keep the appliance off until a competent engineer has cleared and verified the fault. 2) Keep records of the fault, reset attempts and any observations to give to the engineer; this speeds up diagnosis. 3) For anything beyond the basic visual checks and a single reset, always use a Gas Safe registered engineer — do not attempt gas-related repairs yourself.