Error 284

Safety precautions:

1) If you smell gas (rotten egg smell) or suspect a leak, do not operate electrical switches, do not use phones near the leak, open windows and doors, evacuate the property and call your local gas emergency number immediately. Do not try to investigate the boiler.

2) If you do not smell gas, isolate the boiler using the external on/off switch or the fused spur and turn off at the gas service cock only if you are confident doing so. Avoid opening the boiler casing or touching internal components. Wear no special tools or probes around live terminals.

Initial checks a homeowner can do (safe, non-intrusive):

1) Note the full display: record the error code (284) and any accompanying cause codes or flashing indicators. If other codes are visible, write them down.

2) Check other gas appliances in the house (hob, gas fire, cooker) to see if they are working — this helps establish if the house gas supply is present.

3) Check the gas meter and any local gas isolation valve to ensure the supply to the property is on. If you are unsure, contact your gas supplier.

4) Check mains power to the boiler: ensure the fused spur hasn’t tripped and the boiler has power. Check your consumer unit (fuse box) for tripped breakers or blown fuses.

5) Visually inspect the boiler externals for obvious signs of damage, burned wiring, or loose connectors visible outside the casing. Do not remove the boiler cover or touch internal wiring.

6) Inspect the external flue outlet and condensate pipe for obvious blockages or frost (a blocked flue can cause lockouts) and clear any safe, external obstruction like leaves or light debris. Do not force anything into the flue.

Safe reset attempt (only if no gas smell and no other safety issues):

1) Follow the GB162 manual: either press and hold the reset button for around 3 seconds or use the temperature dial reset position as described in your manual. After resetting, return controls to normal and observe the boiler during the next start attempt.

2) Do not repeatedly reset the boiler if the fault returns immediately — repeated resets can mask the underlying problem and may put you at risk.

If the fault clears and the boiler runs normally, monitor for recurrence. If the fault reappears, proceed to call a professional.

What a qualified engineer will do (do not attempt these yourself):

1) Use safe isolation procedures, remove the casing and inspect the gas valve, valve coil, wiring looms and the burner control unit (BCU) or relay that drives the valve.

2) Check for continuity and correct coil resistance on the gas valve coils and check the feedback signal/voltage that the controller sends/receives during a start attempt. Confirm whether the valve is receiving the correct control signal and whether the valve’s feedback matches expectations.

3) Test the burner control unit, relays and any associated code plug for compatibility or errors (some related fault codes indicate incompatible or faulty code plugs / control units).

4) Inspect for wiring faults, short circuits, or connector damage and repair as required.

5) If the valve itself is faulty or the valve feedback is out of specification, the engineer will replace the gas valve or the faulty control module as appropriate, then run commissioning and safety checks including leak and combustion checks.

When to call a professional and what to tell them:

1) Call a Gas Safe registered engineer whenever the fault persists after a single safe reset, if there is any sign or smell of gas, or whenever the boiler shows repeated or intermittent faults. Do not attempt internal repairs yourself.

2) When you call, provide: boiler model (Worcester Bosch GB162), the displayed error code (284) and any additional cause codes, whether you smelled gas, whether other gas appliances work, what initial checks and reset you performed, and when the fault began. This helps the engineer bring the right parts and diagnostic equipment.

Final note: Error 284 indicates a gas-valve related issue which is safety critical. Homeowner checks should be limited to the safe items above and a single controlled reset per the manual. All electrical and gas valve diagnostics and repairs must be carried out by a Gas Safe qualified engineer.