Error FD

Safety precautions:

- If you smell gas, see signs of burning, smoke, or melted wiring, turn off the gas supply if you can do so safely, switch off the electrical supply to the boiler at the consumer unit, leave the premises, and call the gas emergency number and a Gas Safe engineer. Do not attempt internal repairs.

- Do not open the boiler casing or attempt internal electrical work. Only a Gas Safe registered engineer should work on gas or internal electrical components of the boiler.

- Avoid repeatedly pressing the reset button more than a few times. If a reset does not clear the fault after a couple of attempts, stop and get a professional to inspect it.

Initial checks a homeowner can do:

1. Check the house power: confirm other electrical appliances and lights are working so you know whether there has been a general power outage.

2. Check the consumer unit (fusebox): see if any MCBs or RCDs have tripped and reset them if needed. If a breaker trips repeatedly, do not keep resetting it.

3. Check any external isolation switch for the boiler is ON. Ensure the boiler plug (if fitted) is firmly in the socket and the cable shows no visible damage.

4. Note when the FD occurred and any events just before it (power cut, work on electrical circuits, someone touching the boiler, lightning, etc.). Record any other fault codes or indicator lights shown on the display.

Specific diagnostic and fix steps:

1. Try a proper reset: locate the boiler reset button (refer to the manual if unsure). Press and hold the reset button for about 3 seconds, then release. Allow the boiler a minute to reboot and check whether the FD code clears and heating/hot water returns.

2. Power-cycle the boiler: if a single reset does not clear the code, switch the boiler off using the external isolation switch or at the consumer unit, wait 30–60 seconds, then switch it back on and try the reset again.

3. Check for recurring patterns: if FD appears only after a power cut or during stormy weather, that suggests mains supply instability. If FD appears after touching the unit or after work in the same area, that may indicate accidental button presses or loose connections.

4. Inspect visible power connections: with the boiler powered off if you need to touch plugs, check the plug, cable and socket for damage or overheating (discoloration, melting). Replace or repair damaged external leads, but do not open the boiler itself.

5. Observe behaviour after reset: if the boiler restarts and runs normally for a long period, the FD was likely a one-off. If the FD returns quickly or regularly, stop troubleshooting and call a professional.

When to call a professional:

- If the FD fault will not clear after two or three sensible reset attempts and a power-cycle.

- If the FD reappears intermittently or frequently, indicating a persistent electrical or control-board issue.

- If you see other fault codes, repeated tripping of the consumer unit, burning smells, smoke, or any signs of electrical damage.

- If you are unsure where the reset button is or uncomfortable performing the checks above.

What to tell the engineer:

- Give the exact fault code (FD), the boiler model and serial number, when the fault first appeared, what you tried (number of resets, power-cycle), whether there was a recent power cut, and whether any other symptoms (tripping MCB/RCD, smells, other fault codes) were present. Photos of the display and the boiler location can help.

Summary:

The FD error is usually simple and often resolved by a short reset or by restoring mains power. Do basic safety checks yourself, perform a controlled reset and power-cycle, and inspect external power connections. If the fault persists or if you have any electrical concerns, stop and book a Gas Safe registered engineer (and an electrician if consumer-unit trips or wiring faults are suspected). Do not attempt internal repairs on the boiler yourself.