While you wait for answers, we may have found some information which could help you.
Click here for Burner Boiler LockingWorcester heatslave 20/25?
How to switch off lock out light?
how many rads can a worcs danesmoor 20/25 run ?
how do I remove the burner from my Worcester Bosch 15/19 - ?
worcester heatslave 20/25 central heating but no hot water?
worcester danesmoor 20/25, lockout/repriming tigerloop and pump?