Error S.58

Safety precautions:

- If you smell gas, evacuate the property and call the gas emergency number immediately—do not operate electrical switches or the boiler.

- Install or ensure a working carbon monoxide alarm is present.

- Do not open or attempt to repair gas or sealed parts of the boiler yourself. Only a Gas Safe engineer should work on internal gas, electrical or flue components.

Initial homeowner checks (safe, no-tool checks):

1. Note conditions when S.58 appears—does it happen only in strong winds or stormy weather? Is the flue terminal exposed to prevailing wind?

2. Reset the boiler once: switch off via the boiler power button or isolator, wait 30 seconds, and switch on again. If the code is intermittent and caused by a gust, it may clear. Do not repeatedly reset more than 2–3 times if it returns.

3. Inspect the external flue terminal (outside the property) visually from the ground or a safe vantage point: look for blockages (bird nests, leaves, debris), damaged flue cowl or non-return flap, loose grille, or anything that could disturb airflow. If you can safely remove superficial debris by hand or by gently brushing it away, do so. Do not insert objects into the flue.

4. Check that air vents or combustion air inlets (if present) are not blocked by furniture, plants or foliage.

If the fault persists after initial checks:

5. Photograph and note the exact error behavior (when it occurs, how often, local weather conditions). This information helps an engineer diagnose intermittent wind-related faults.

6. If the external flue cowl, non-return flap or terminal looks damaged or is loose, do not attempt internal repairs—book a Gas Safe engineer to replace or secure the flue termination. A damaged cowl or flap can cause frequent S.58 codes.

7. If the issue is not weather-related (occurs indoors or even when calm), suspect a faulty fan, flue pressure sensor/switch, or wiring to those components. These parts require specialist diagnostic equipment and safe isolation of gas/electrical supplies—call a Gas Safe registered heating engineer.

When to call a professional and what they will do:

- Call a Gas Safe engineer if the code returns after clearing external blockages/reset, if the external flue or cowl is damaged, if the boiler frequently locks out, or if you detect any other combustion irregularities (smell of gas, soot, unusual flames, or persistent error codes).

- The engineer will perform safe diagnostics: read fault history from the boiler, test flue pressure and fan operation, check flue terminal flow and non-return flap operation, inspect wiring and sensors (pressure switch, fan tachometer, PCB inputs), and replace faulty components if needed. They will also confirm flue termination suitability for your location and may fit a different cowl or reposition the terminal if wind is the cause.

Final notes:

- Do not attempt internal electrical or gas repairs yourself.

- Repeatedly resetting a boiler without resolving the cause may mask a fault and lead to further problems; get a professional if S.58 keeps returning.

- Keep records (dates, weather, photos) to help the engineer diagnose intermittent wind/noise related faults quickly.