Error FD 231

Safety precautions:

- If you smell gas, leave the property immediately, do not operate electrical switches, and call the gas emergency number.

- Do not open the boiler casing or attempt internal electrical repairs; only a Gas Safe registered engineer should work on gas appliances and a qualified electrician on mains wiring.

- If you see signs of electrical burning, scorched wiring, or water contacting electrical parts, switch off the boiler at the consumer unit and call a professional.

Initial checks a homeowner can do:

1. Check for a general power outage: look at other appliances or ask neighbours whether they have power.

2. Check your consumer unit (fuse box) for any tripped MCBs or RCDs and reset them if safe to do so.

3. Locate the boiler isolator or fused spur (often a switch or small box near the boiler) and ensure it is switched on. Check the fuse in the fused spur or plug if accessible.

4. Visually inspect the boiler power lead and plug (if fitted) for obvious damage — do NOT remove any covers or access internal wiring.

Specific diagnostic and fix steps:

1. If household power was interrupted or you had a tripped breaker, restore power and then go to the boiler.

2. Attempt a single reset of the boiler: press and hold the boiler reset button (or follow the reset procedure in your manual) for a few seconds and release. Wait up to 5–10 minutes for the boiler to reboot and attempt ignition.

3. If the boiler clears the FD 231 and returns to normal operation, monitor it for recurrence over the next 24–48 hours. One-off faults after a power cut are common.

4. If FD 231 returns immediately or repeatedly after reset, do NOT keep resetting the unit. Repeated lockouts suggest an electrical fault such as loose wiring, failing internal components (PCB), or a problem with the boiler’s power supply.

5. If there is any visible damage to the external power cable, scorch marks, or the fused spur appears damaged, switch the boiler off at the consumer unit and arrange for a qualified electrician to inspect/repair the mains wiring before using the boiler.

6. If the boiler shows other fault codes alongside FD 231, or if resetting does not clear the fault when mains power is confirmed OK, contact a Gas Safe registered engineer to inspect and repair the appliance.

When to call a professional (and why):

- Call a Gas Safe registered engineer if FD 231 persists after household checks and a single reset, if the code recurs frequently, or if other faults appear. Persistent power-fault codes can point to internal wiring issues, a failing control board, or other faults that require specialist diagnosis and replacement parts.

- Call a qualified electrician if you find tripping breakers, damaged mains wiring, or a faulty fused spur.

Final note: a single FD 231 after a known power cut or a mistaken reset is usually resolved by restoring power and performing one reset. Anything beyond that — repeated faults, signs of electrical damage, water ingress, or gas smell — requires immediate professional attention. Do not attempt internal electrical or gas repairs yourself.