The controller (MPPT-273) connecetd to my Victron inverter has failed after only 15 months. The installer tells me the whole inverter, not just the controller, must be returned to Victron. Is this correct? The installer removed the controller and left the inverter working using another controller i.e. MPPT 150 1 35 that takes power from a different set of panels. So the inverter is working, but we are not using the second set of panels. I simply want to know if Victron will insist on the inverter also being returned, even though it is working?