Error E.02 – .47

Safety precautions:

- If you smell gas, evacuate the property, do not operate switches or naked flames, and call the gas emergency service and a Gas Safe engineer immediately.

- Turn the boiler off at its power switch and at the isolator before touching electrical controls. If you must remove covers on external controls, isolate their power first. Do not open the boiler casing or touch internal components unless you are qualified.

- Work in a well-lit area, use insulated tools, and avoid contact with live terminals. If in doubt, stop and call a professional.

Initial checks a homeowner can safely do:

1) Note the exact error code (E.02-.47), take a photo of the display and the boiler serial/label for the engineer.

2) Try a simple reset: use the boiler reset method (reset button or selector R held for 5–10 seconds). Wait and see if the fault clears and whether it returns. Do not keep repeatedly resetting more than once or twice.

3) Check external control power: ensure the room thermostat, programmer or wireless receiver is powered and calling for heat if appropriate. Replace batteries in thermostats or handsets.

4) For smart/wireless devices: check the app or receiver LEDs for pairing or fault status and restart the device/router if applicable.

5) Check system pressure on the boiler gauge (aim for around 1–1.5 bar when cold). Low pressure can cause other errors and mask diagnosis.

6) Visually inspect any accessible wiring and terminals at external devices (thermostat, timer, receiver). Look for loose screws, disconnected cables, corrosion or chewed/and pinched cables. Do not touch live wiring. Tighten screw terminals only after isolating power to that device.

Specific diagnostic steps and possible fixes (homeowner-level):

1) If the external device is a wireless receiver or smart hub, try power-cycling it and re-pairing per the manufacturer instructions. Some wireless receivers lose pairing after power outages.

2) If the external device is a simple wired thermostat or programmer, try turning it off or isolating it (switch off its fused spur or remove its batteries) and then reset the boiler. If the boiler clears the error and fires normally when the external device is isolated, the external device or its wiring is the likely cause.

3) If you have basic electrical competence and have isolated mains power, you can remove the thermostat cover and check the wiring termination is secure. Do not probe live terminals. If terminals look damaged or wires frayed, leave replacement to a professional.

4) If you can safely access the external device and the manufacturer gives a non-technical method to bypass (for example, a link plate for two thermostat wires), you may temporarily bypass the device to confirm the boiler will run without it. Only do this if you are confident and the bypass method is explicitly allowed by the device documentation. Otherwise do not short or rewire terminals.

5) Observe behavior after isolation/bypass: if the fault no longer appears, replace or repair the external control or its wiring. If the fault remains, the issue is likely on the boiler side (PCB, terminal block, internal wiring) or a more complex pairing/configuration fault.

When to call a professional (and what to tell them):

- Call a Gas Safe registered engineer if the fault persists after the basic checks above, if you are uncomfortable performing any of the checks, or if you need any internal inspection or wiring repair inside the boiler.

- Call immediately if you smell gas, see water leaking from the boiler, have repeated lockouts, or if the engineer will need the full fault history — give them the exact code E.02-.47, the steps you took (reset, isolated external device, battery changes, photos), and whether the fault cleared or returned.

- Do not attempt to replace the PCB, gas valve, or any gas-carrying components yourself. Those items require a qualified engineer.

Final notes:

- E.02-.47 points to a communications/wiring problem with an external control — often fixable by repairing or replacing that device or its wiring, but diagnosis sometimes requires checking the boiler's terminal block and PCB by a professional.

- If in any doubt, stop and book a Gas Safe registered engineer to avoid unsafe work or invalidating warranties. Do not provide payment/cost estimates here; get a quote from a qualified service when needed.