it's siphon fill mode, it's activated after the power has been off on worcester greenstar boilers and it's quite normal. if it comes on without the power being turned off then you need a new pcb.
Ian, April 2011
Haven't got a clue. a bit like your question!
DB, April 2011
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I can answer this question...
i have a symbol that i dont know the symbol is -||-?