Resetting Biasi Riva Compact HE Combi

Discussion in 'Engineers' Talk' started by remah, Feb 17, 2021.

  1. remah

    remah New Member

    Hi guys,

    Owing to dhw problems, I have recently replaced the pcb on my biasi model number M96.28SM/C2. The boiler was reset in accordance with section 10.7 of the service manual. All seemed fine and the sequence of the operating lights was as per the manual however the dhw problem still persisted.
    After research on various forums the cause pointed to the main flow switch diaphragm.
    The boiler was drained down and to ease access I disconnected the central heating temperature probe and replaced the diaphragm. The boiler was re-filled and both heating and dhw was operational albeit the pin in the main flow switch didn't move when I opened the hot tap. It did however fully extend to operate the micro switch when in heating mode.
    I have checked the setup as per the service manual and it appears now to be set up in central heating only mode. The problem now is I can't seem to set it back up as a combi boiler from it's present set up.
    Is there a way to re-set the pcb back to the start of the set up sequence.

    Any positive comments would be most welome.

    Btw, the pcb probably didn't need replacing but I was just following the fault finding notes in the service manual.
    terrymac likes this.
  2. remah

    remah New Member

    Sorry, not the main flow switch diaphragm but the Primary Circuit flow switch diaphragm.

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