Sorry for the hijack cuppa, but I have a main and sub tank and find that the sub tank leaks into the main even when the switch is not on, not at a great rate but overnight I can see a change on the gauges. Is this by any chance a common issue with the setup.
Mines a 2000 TD42T and I dont get any faults or alarms but am interested to know if this may be due to a faulty pump or maybe a rogue ockie strap protector to!