This part fits:
Worcester Greenstar ErP Compact SI 25
Worcester Greenstar ErP Compact SI 25 LPG
Worcester Greenstar ErP Compact SI 30
Worcester Greenstar ErP Compact SI 30 LPG
Worcester Greenstar ErP System Compact 27I
Worcester Greenstar ErP System Compact 27I LP
Worcester Greenstar ErP System Compact 30I
Worcester Greenstar ErP System Compact 30I LP
Worcester Greenstar ErP Compact 533
Worcester Greenstar ErP Compact 535
Worcester Greenstar ErP Compact CDI 28
Worcester Greenstar ErP Compact CDI 28 LPG
Worcester Greenstar ErP Compact CDI 32
Worcester Greenstar ErP Compact CDI 32 LPG
Worcester Greenstar ErP Compact CDI 36
Worcester Greenstar ErP Compact CDI 36 LPG