Replaced pub now flashing h5 not sure where the pins go

Paol, August 2017

If you have replaced the pcb
There is normally a small manual explaining how to CONFIGURE the pcb to your specific MODEL boiler
ie icos HE12 HE15 HE18 HE24 HE30 HE36
Depending on which model
Depends on which position JUMPER LINKS are fitted

Ring ideal tech if you are totally stumped

Asbestos, August 2017

Neither are we. You have not told us the make/model or what ins you are talking about.

Best bet is to get someone competent to look at it

Acp, August 2017