Worcester Bosch 284 Fault Code
The Worcester Bosch 284 fault code means: your boiler is struggling to deliver the correct mix of air and gas required to light the burner safely.. It appears on 21 Worcester Bosch models in our database.
Technical description: Opening air/gas ratio control valve/oil solenoid valves
What causes the Worcester Bosch 284 fault?
This fault occurs when the boiler's internal computer is unable to communicate with or control the valve that regulates the flow of gas into the burner. It signifies a hardware failure where the gas valve remains closed or unresponsive, preventing the boiler from creating a flame to provide heating or hot water. The most common reasons include a faulty electronic control board, a loose wiring connection, or a mechanical failure within the gas valve itself.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Worcester Bosch models that show the 284 fault code
Click a model for the full fault code list and model-specific repair notes.
- 1000 Repair: £150-300
- 24 RSF Repair: £180-£350
- 26 CDi Xtra Repair: £150-£350
- 30i Junior Repair: £180-350
- 35 RSF Repair: £180-450
- Danesmoor Repair: £180-350
- GB162 Repair: £250-450
- Greenstar 12i System Repair: £150-300
- Greenstar 2000 Repair: £180-350
- Greenstar 27CDi Repair: £180-350
- Greenstar 28CDi Repair: £180-350
- Greenstar 4000 Repair: £150-300
- Greenstar 8000 Repair: £180-350
- Greenstar 8000 Life/Style Repair: £180-350
- Greenstar 8000 Style Repair: £180-350
- Greenstar CDi Compact
- Greenstar i Repair: £150-300
- Heatslave Repair: £180-350
- Hideaway Repair: £180-450
- Junior 24i Repair: £180-350
- Junior 28i Repair: £180-350
Source
Worcester Bosch 284 fault code information on this page is sourced and cross-checked against the official Worcester Bosch service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026