Whale water heater not working. Space heater seems ok. Elddis 115. Red exclamation mark next to tap control on duo panel shows up continually. Tried reset button on underfloor heater unit top panel, single press, extended double press etc. Tried pressing tap image on duo panel and plus button many times. All lights light up on heater lower panel when I do that, very occasionally a quick flash of the gas flame on water heater panel. Gas is on in the van and working ok. Also tried turning on and off van power panel. Don't know how to turn off RCD unit. Presently on site in S. France. Jimbohorlicks where are you?.