Hiya,
6 flashes is normally the flow meter. Bad connection is the favourite, unplug it, clean pcb, tighten plug, plug back on and it should work.
Complete metering tank if you want to change the flowmeter.
Seeing as we’re on Diplomat D’Ws i’ve been to one today an ADP8352 that will only show P0 on display, won’t reset to any other program. Is it a dodgy electronic or any other ideas ?