TradeAssistIQHome

Worcester Bosch Greenstar 4000 System fault 228

Flame signal without flame present

Gas boiler

What it means

Locking fault (V category). The appliance is detecting a flame signal when no flame is actually present.

Likely causes

  1. Damaged ceramic insulator causing spark to earth
  2. Faulty flame sense or lead
  3. Poor earth tags on boiler or electrodes
  4. Faulty siphon operation causing water collecting in sump
  5. Faulty gas valve
  6. Faulty control unit and/or burner control unit

Where to start

  1. Check the ceramic insulator is not damaged; twist and pull to ensure it is not broken.
  2. Check the flame sense and the lead and replace if required.
  3. Check the earth tags on the boiler and on the electrodes.

The full answer, free

  • 1 more check in order
  • How to put it right, step by step
  • The manual page for this fault (page 71), right under the answer
Ask about 228 freeCreate a free account

Safety: Isolate gas and power before you open the case. If you have been into the gas side, do a tightness test, and a combustion and flue check before you hand back. Gas Safe (UK) or RGI (Ireland) work only.

From the Worcester Bosch manual for the Greenstar 4000 System. Check the model on the data plate before you order parts.

Other Worcester Bosch Greenstar 4000 System fault codes