The ELCB protecting the Distribution Board that powers our Baxi 105E has started tripping quite frequently. Mostly when the boiler is off, but occasionally when on. (Mainly by virtue that it is off more often than on!) If it trips when on, and the flame on symbol is showing on the room stat, I have to lower the room stat set point to knock the flame off, and increase it again to switch the boiler back on (which presumably is a function of the operation of the Room Stat). However, what could cause the boiler, if it is that, to trip the ELCB? Thanks.